Hi there ! You still with me ? Amazing ! Even more amazing is the fact that you are probably still using a 2400 bps modem.

Picture this:

You just logged into your favourite online host (possibly a BBS, Compuserve or your company’s mainframe) from across the country. There is this massive file you just HAVE to download. The remote host graciously informs you how long it is going to take – just over an hour ! Hmm, let me see – that is 60 minutes multiplied by 60 seconds divided by 2 (being the pulse rate from Bangalore to Delhi). That is 1800 smackeroos ! Wow! Who is going to pay for this ? Your company ? Then that’s OK. What ? You mean YOU are paying for this? Are you out of your mind ????? Stop mumbling about “2400 bits per second is the fastest one can go here”. That was in January this year (when you read my first column in PC Quest). Times have changed – high speed modems have arrived.

Improvements all around

1993 is probably going to be the year when low speed modems finally get to be consigned to the museum here in India. Earlier this year, modem manufacturers introduced reliable 14400 bps modems in this country. I myself was a bit skeptical – how were these speed demons going to perform on our “miserable” phone lines ? Actually, they perform quite well – amazingly well, as a matter of fact. You see, not only have new modems brought in new and improved technology that is better equipped to handle our lines, the Indian telephone system itself has seen quite a number of improvements. For example, most telephone exchanges in the metros (and Bangalore, the metro-that-the-powers-refuse-to-call-a-metro) have gone electronic. The clicking, popping, crackling crossbar exchanges that were once the bane of Indian datacomm are historical relics in many of these cities. Also, the P&T seems to have woken up to the fact that phone lines have a finite life, and need to be replaced at least once per century. Finally, with more exchanges in the circuit, the infamous “last mile” has been reduced considerably, thereby reducing the pickup of noise along the way. Quality of long-distance lines has improved noticably. Today a call from Bangalore to Delhi is normally clearer that a call to an office across town.

Welcome to the Fast Lane!

So what’s the current definition of high speed according to Atul Chitnis ? The simple answer is – anything faster than 9600 bps. This effectively means 14400 bps or better. With V.42bis compression, that can be almost 57600 bps or 5.76 kiloBYTES a second ! One nice thing about high speed modems faster that 9600 bps is that many (if not all of them) are compatible with each other. When 9600 bps modems first arrived here, there were a lot of problems, with different makes of modems refusing to talk to each other. No such problem at 14400 bps – ALL of them use the V.32bis standard for transmission, ALL of them have V.42 error correction and ALL of them use V.42bis compression. There are NO non-error correcting 14.4K modems. Three cheers for standards ! Communicating at 14400 bps is a nice feeling. Six times faster than a 2400 bps connection, things seem to fly. The one hour transfer described at the beginning of this column drops down to 10 minutes, or about 300 bucks STD cost. Since we are talking V.42bis compression here, things could be faster than this, and even ZIP files (a nightmare to transfer using MNP5 when the protocol tries to compress something Phil Katz’s PKZIP 2.04G couldn’t compress any further) trundle along at a respectable rate.

Here is the good news…

Modems in India tend to be expensive, but luckily it has always been a “you get what you pay for” situation – the more expensive modems tend to perform much better than the cheapos. Until recently, a decent 2400 bps modem cost around Rs.20,000, with a few low-cost guys robbing you for around 15K. Today, a decent 14400 bps modem will cost you about 34K (and dropping). That’s six times the speed at about 1.5 times the price ! Not a bad deal, what say ? If you consider the savings in transmission time, you don’t have to be Shakuntala Devi to realise that you make up the cost of the modem in a very short time.

Resistance to change

Sad, but true. Many large corporates still follow the beaten path of being “penny wise, pound foolish”. Recently, a HUGE corporate I know went and bought a stack of 2400 bps MNP modems, thinking that they saved a lot of money in the bargain. Oh really ? Look at these figures: 20 modems x Rs.20,000 = Rs.400,000 Assuming 100 KB data transmission per day per modem (typical in corporate setups), then at 2400 bps it is 20 x (100 x 1024 /240) = 8533 seconds a day, or about Rs.4266 per day at 2 second pulse rates. (2400 bps is 240 BYTES per second) If they would have bought 14400 bps modems instead, it would have been 20 modems x Rs.34,000 = Rs. 6,80,000 and 20 x (100 x 1024 /1440) = 1422 seconds a day, or about Rs.711 per day at 2 second pulse rates. Now multiply transmission costs over a year of 200 working days, and you get Rs. 8,53,200 when using 2400 bps modems and Rs. 1,42,200 when using 14400 bps modems. So the sum total for the “2400 bps wallas” is 12.5 lakhs in the first year, while the “14400 bps wallas” pay only about 8.22 lakhs. Also consider that the 2400 bps modems may seem “state-of-the-art” to your finance department, but a year down the line, they will feel like 8088, 4.77 MHz single-drive CGA PCs do today. The 14400 bps modems, though, will continue to hold their own over a couple of years. 19200-to-24000 bps modems are already available in the USA, 28800 bps will be here before mid-’94, so that 14400 will very soon be entry level. Consider, too, that most of the new 14.4K modems also incorporate fax capabilities, some at 14.4K – much faster than current stand-alone fax machines, and the savings add up, especially when a good fax machine alone costs almost 50% more than a 14.4K fax modem.

The downside

“OK, Mr.A. So 14.4K modems are faster, but who guarantees that they will work consistantly at that speed ?” Not me. Not today. I CAN virtually guarantee sustained performance between metros and within the city, but if your trunk line goes through a couple of lousy crossbar exchanges, then things are likely to slow down. To maybe 12,000 bps, 9600 bps or even 4800 bps. But even in a worst-case scenario, that’s twice as fast as the 2400 bps relic you are planning to purchase ! And many 14.4K modems have a feature thats allows the modem to fall back when the line goes bad, and fall forward again when conditions improve. I CAN guarantee that with improvement in line conditions (as it is happening almost daily), it will be more than likely that you will be able to transfer at maximum speed. One factor that MUST be considered, though, is handshake time. High speed modems tend to take a much longer time to establish a connection initially, typically from 5 to 15 seconds as opposed to 1-5 seconds for 2400 bps modems. So all that high speed may not really pay off if you are only transferring a kilobyte or two of data per day, since the total of handshaking and actual transfer in a 14.4K modem may be longer than the handshake and transfer of a 2400 bps modem. But the, any 14.4K modem can be forced down to 2400 bps if needed, and will perform better than any 2400-only modem can.

Cheapos and Foreign returns…

“Phoren ish besht !” is the accepted credo in most circles. Sez who ? Pick up that incredibly cheap modem in the USA, and you’ll soon understand why it was so cheap. Cheap performance, cheap components and no after-sales support all add up to a disaster. Also remember that 99% of cheap American modems are made in Taiwan or Korea, so the “Made in the USA” tag is no guarantee of performance. And don’t forget the P&T watch dogs who are just waiting to hear that 14.4K carrier tone on your line before slamming you for using a non-TEC cleared modem. Foreign modems are NOT cleared by the P&T, so this is not a game of roulette you should play. If I am beginning to sound like a salesman for a modem company, forgive me, but I am stating facts that I gathered from experience. So before you ask your friend/relative/associate/well-wisher in the USA to pick up a modem for you, think twice. You are likely to end up paying twice as much as it would cost you here. Remember – there is nothing like a free lunch.

Fast Modems need Fast Machines

A critical issue in high speed modem usage is the speed of your machine. You CANNOT use a 14.4K modem on a XT with an 8250B UART, a 20MB ST225 hard disk and a 3-wire serial cable. Period. An 80286 or better machine IS required, and preferably a 16550AFN UART (serial communications) chip. And the serial cable must have all nine critical connections wired up to allow hardware flow control. Anything less, and you are asking for trouble.

Which modem is the best ?

On an average, I am asked this question about 50 times a day, via e-mail, snail mail and telephone calls. I have used high speed modems made by a number of manufacturers, but to date haven’t really sat down to do a complete evaluation. I did ask some manufacturers for evaluation pieces, but all of them seemed to think that modem evaluation is a 30 minute job. No way. Anyway, as soon as I have done a fair and comprehensive evaluation of some of the 14.4K modems available in India, PKR and I will sit down and have a “modem special” that tells you of our findings (provided you are interested – write to The Editor, PCQ, and let him know). Until then, I can only say “no comment”.

Saving money

One of the objectives of my articles is to help you save money. If you are a reasonably heavy Compuserve user, then a high speed modem is likely to help you save. The trick is – call the Compuserve node at Hong Kong (00852-3041332). This is a 9600 bps node with V.42 error correction (as in all carrier networks, it does not support compression, so make sure you disable it with AT%C0 or AT&E14 before calling). If you have a fairly long Compuserve session ahead of you, calling Hong Kong is mucho cheaper than using INET, which charges you Rs.200/64K. The call to Hong Kong is tariffed at 1.2 seconds per pulse (at least something good about being a SAARC country), and you will get an effective throughput of about 750 chars per second as opposed to about 170 chars per second via INET. A 1 MB file transferred from Compuserve will cost you about Rs.1200 via Hong Kong, and about Rs.3200 if transferred via INET. It will also take a lot less time via Hong Kong.

Bombay modem users, please note:

The Bombay MTNL people have introduced an innovative(?) way of telling you that you have crossed the 5 minute limit for a local call – it gives you a loud BEEP. Unfortunately, the decision makers up there don’t seem to use modems. A beep like that immediately breaks any modem connection. A gigantic BOOOO! is called for, and is herewith given. Until the people at MTNL come to their senses, you can avoid the cutoff by setting your modem’s S10 register to a value of 25 or higher. The default value of 14 stands for 1.4 seconds, which is too short to handle the MTNL folly. Setting it to a higher value will keep the connection alive inspite of the beep. You may have to experiment a bit to get the right value. By the way, from the appearance of things, the telecom people at Bangalore DO use modems – no beeps here. Makes you want to move, doesn’t it ?

Gimme a break

I have said it before – I’ll say it again. Writing for PC Quest is one thing – answering personal letters and queries via e-mail and phone calls is another. PLEASE do not flood me with letters and calls asking me questions. I am being bombarded with queries ranging from modems to networks, from DOS to games and from programming issues to requests for pirated software ! I do not wish to sound like a mercenary, but my company does professional consulting – if you are willing to pay for the information that we provide, by all means call. If not, please write to me c/o The Editor, PC Quest, New Delhi. Or, even better, make sure you have a PC Quest subscription – most of your questions are likely to be answered in future columns. At Rs.149 a year for a subscription, that’s a steal. As far as bouquets and brickbats are concerned – I am open to any suggestions or criticisms. Feel free to fire away. Writing to The Editor, PCQ will give you the added advantage of having PKR on your side – he’ll soon set me right. This time, I’ll say bye in the Bombay MTNL way…. BEEEEEEP NO CARRIER

IT HAPPENED ONE NIGHT….

It is late at night. I am sitting at my desk at home, my daughter is finally asleep, my wife is grumbling something about “Computer Widows”, Eric Clapton sings the blues on the Walkman, and my computer hums along quietly.

All of a sudden, I have this terrific urge to reach out and communicate.

Now unless you know of more “night owls” like me, calling someone up at 2 a.m. is likely to make you enormously unpopular in no time.

But if you have access to a phone line and a modem, then there are places that will not only welcome you – they are eagerly awaiting your calls !

I am talking about your local (or not so local) BBS (Bulletin Board Service).

Instead of trying to describe a BBS technically, let me take you through a brief tour of my local BBS, and I am sure you’ll get the idea.

A BBS TOUR

Using my modem, I dial the BBS phone number. A few squeals later, the modem connects, and I am greeted by a sign-on screen that welcomes me and prompts me to “log in”./

I type in my User ID and password, and seconds later, the world opens up to me.

A flashing sign tells me that my Electronic Mailbox has new messages for me. Bulletins tell me what’s new on the system, and a scan of the system tells me that there are dozens of new messages and files in the various forums.

First of all, I go and read my mail. I make the appropriate selection from the menu that appears, and find myself in the E-Mail area of the BBS.

I read the messages waiting for me. There is one from Raju, saying that he’ll be coming in late tomorrow since he he has some work lined up for the morning. And there is a message from Kishore in Delhi – he’s hopping mad because I haven’t sent him the promised upgrade!

OK, enough of mail – let’s see what’s happening in the forums.

I exit from the E-Mail area, and enter the PCQ forum.

A bunch of new messages, including one from Mahi – he suggests that I should upload the utilities mentioned in my articles into the forum library for others to download. “Good idea” I respond in a message of my own, and proceed to upload the said utilities. I also leave a message for all members, asking them if they know of any way by which one could make PKR from PC Quest get a modem and join the BBS.

Over at the Virus forum I find that user Bhargava has uploaded the latest versions of McAfee’s shareware anti-virus programs. A few minutes later I have transferred them to my computer.

Suddenly I remember that I need to find out who sells UPSs in Bangalore – a trip to the Electronic Yellow Pages database soon gives me all the info I need, complete with addresses and phone numbers.

Right – enough of this tour. After a quick trip to the NEWS room, where I pick up the latest computer industry news file, I disconnect from the BBS, and “surface” to find myself back in my room at home again.

Just a couple of years ago, all of the above would have been possible only if I was in the USA, but today even India is getting its fair share of BBSing. A new BBS seems to spring up every day in Bangalore, Bombay, Delhi, Madras and even smaller towns. Some of them are strictly private, meant for use of company staff, some, like the one I just described, are open to the public, either completely free or on semi-commercial (i.e. cover the running costs) terms.

And a good thing it is, too. BBSs have been, to a great extent, responsible for the information explosion in the USA. Now the same thing is beginning to happen in India.

Let’s rewind a bit, and see what a BBS is and how it works.

WHAT’S A BBS ?

For those of you who have been using modems to communicate with another person at the far end, a BBS will be a sort of a surprise – there is NO human at the other end !

Instead, all your interaction with the system is handled by the BBS software and the modem – that includes all the prompts, menus, file transfers, message handling and other operations. As a matter of fact, the only time you’ll actually have human contact on a BBS is if you go into “chat” mode with the System Operator or another user who may be online.

Many of you will have heard, or even used, E-Mail and Information Services such as Compuserve, MCI Mail and British Telecom Gold. These are gigantic commercial communication services that you can log into from anywhere in the world and access a vast range of services, including Electronic Mail, databases, forums, specialised information services, etc.

Well, a BBS is something very similar to, say, Compuserve, but instead of running on huge mainframe computers servicing thousands of people at a time, a BBS runs on a plain-vanilla PC, servicing a couple of users at a time, one after the other. Instead of running somewhere in the world, the BBS runs in your local neighbourhood – a sort of electronic club house. In fact, even the venerable Compuserve started off as a multiline BBS at one time !

WHAT DOES A BBS OFFER ?

Facilities available on a BBS range from simple E-Mail to complex database services, from simple file areas to massive libraries of information.

Unlike a commercial information service, a BBS is VERY easy to set up – all you need is a phoneline, a computer and the necessary software. And, of course, someone to call in.

Instead of a dedicated team of people, a BBS is usually run and maintained by a single person, usually known as the SYSOP (System Operator). He or she is the lord of the domain, and decides what goes on.

What sets BBS apart from commercial information services is (apart from the obvious difference in size) the fact that most of the people using the service know each other (or soon will), and tend to interact as friends, usually on first name terms.

Forums on a BBS (sometimes known as conferences or SIGs – Special Interest Groups) form areas where specific topics are discussed. For example, the PCQ forum I talked about earlier is used by BBS members to publicly discuss my articles, as well as make suggestions or throw a few brickbats. A message posted in the forum can be read by all members having access to the forum, and any member can reply to or comment on a message, thereby continuing what is known as a “thread” of messages – a sort of sub-topic to the forum.

Most BBSs have file areas – places where members can place or retrieve files. Generally known as libraries – these areas are normally grouped along with the message areas of the same topic – i.e. the Anti-Virus Library is right there with the Virus message base. This makes it easy for members to locate particular files.

A not-so-common feature is databases. Some BBSs provide tons of information in such databases, which can be queried similar to the way you would query, say, a dBASE file. For example, you could tell the BBS that you are looking for UPS manufacturers located in Bangalore, and the BBS software would, based on the given conditions (PRODUCT=UPS, CITY=BANGALORE), filter out the required records for you from among thousands of other records. Private, company-run BBSs make available pricelists, stock status and customer information to their staff.

A BBS is also a great place to make friends. Since you can hide or reveal things about yourself just as much as you want to, you do not have be bothered about things such as age, sex or occupation. For example, I have made friends with a retired Test Pilot, a computer consultant, an 11 year old schoolboy, a financial consultant, a magazine publisher and a brewery owner via BBSs. Some of them have now started their own BBSs, thereby helping with “spreading the culture”. Months (sometimes years) passed before I ever got to meet any of them face to face, but when I did, we were already the best of friends.

THE LOOK AND FEEL

A lot of a BBS’s character stems from the way it is run, meaning that it more or less reflects the Sysop’s own personality.

For example, the Kishore’s BBS in Delhi is a great place to be connected to – messages, though mostly serious in nature, tend to have a hint of humour to them. Some of them are hilarious enough to bring the house down. I recall a particular discussion in the Windows forum, where a couple of Macintosh and PC users had a slug-out that went on for months, and every message was funny enough to drive tears of laughter to your eyes.

Being the Sysop of my own BBS, I will refrain from commenting on its character – you’ll have to log in and judge for yourself.

GETTING CONNECTED

OK, enough of drooling – let’s get you connected. First of all, find out the number of your nearest BBS. Set your communication parameters to 2400-N-8-1, and dial the number. If you hear a modem answering, you are getting there.

Some BBSs (like my own) use a device that detects a voice or modem call and routes the call accordingly. It does this by saying “Hello” a couple of times. If a human voice responds, it rings the phone, else it’ll ring the modem. If you DON’T get connected to a modem, don’t dial again repeatedly – some BBSs run only during certain hours of the day – call voice and check with people at the other end.

Once the modem has connected, you will be prompted for a User ID and password. Most BBSs allow you to register online by entering “NEW” as the User ID, after which it will take you through a short registration procedure. Be honest and complete while answering the questions that will be asked – don’t enter a fictitious name or address. Most BBS Sysops will check the details and may even call back on the supplied phone number to verify them before granting access to the BBS. The real name and address of the member are rarely made public unless the member specifically requests it.

If a BBS charges a small amount for the access, it usually gives you some free time to explore the system before you decide whether you wish to pay. The amount payable is normally very small – just enough to help cover the costs of running the BBS. Many BBSs are completely free.

A BBS rarely assumes anything special at the caller’s end – any computer with a modem and some sort of communication program, such as Procomm, Telix or Crosstalk, will do.

As a matter of fact, this creates another bonus – the people calling into the BBS need not be using PCs at all ! For example, I have used my PC and modem to communicate with Niyam in Delhi, who uses a Macintosh (and HATES PCs!) But I can send him a graphics file that I have created on my PC, and he can view that file on his Macintosh – a process not easily achievable if you want to use diskettes, since there is a disk compatibility problem. All I have to do is to upload the file into the BBS, and he downloads it from there.

LOOKING AROUND

Working with a BBS online isn’t any more difficult than using most PC software today. Usually, the entire works is menu driven, meaning that you only have to pick the right selection to have something done. Many BBSs use ANSI terminal sequences to generate bright and colourful screens and menus, pleasant (and sometimes amusing) to look at and easy to use.

Once you are online, feel free to explore. If you need help, use the help function or leave mail for the Sysop. Some BBSs have a chat facility, which allows you to “page” the Sysop. If the Sysop is around, he may come online and you can “chat” via your keyboards and screens.

Don’t hesitate to say something in a forum or conference. The sooner you do, the faster you are likely to feel the real power of “BBSing”.

While many BBSs will have large selections of files available for downloading, don’t call the BBS just for that. Try interacting with other members, and upload files yourself. Just make sure that the stuff you are sending is not virus infected or pirated – something that could cause your account to go down the bit-bucket very quickly.

WINDING UP

Oh, oh. Out of space again. OK, before quitting for the day, here is some info for you. Many readers have written or called me, asking me questions about this column, and also where they can get the utilities that I sometimes refer to. For this purpose, I maintain the PCQ forum on my BBS. You can pop your questions and comments there, as well as download the said programs. You can also send me e-mail on the system – address your messages to SYSOP.

Next month, I continue this thread by telling you how to call long distance without wrecking the budget.

Until then – Cheerio !

In my past articles, you will have found some reference to Compuserve. After each one, I have been bombarded by questions from readers on how to access Compuserve, what one can find there, how much it costs, etc. Finally, PKR from PC Quest called saying, in effect, that I had teased my readers long enough, and that it was time to cough up the goods. OK, your wish is my command. So, Ladies and Gentlemen, I give you the world’s biggest, best known and most popular Online Information Service – Compuserve.

A little background:

Most of my readers will not really be interested in Compuserve’s history, but let me quickly cover the essentials. Compuserve Information Service (CIS) began as a large computer time sharing setup that made computer time available to people who otherwise had no computing resources. It gradually grew into an information service that today acts as a host to almost a million users world-wide. Initially utilising computer time on various mainframe computers during off-time hours, it now runs on a bank of powerful mainframes located in Columbus, Ohia, in the USA. It has been around for almost a decade, something that is easily recognisable from the name – “Compu” is a prefix that was being used to death in the 80′s in the USA, and even today in India. What makes Compuserve so popular is the mind boggling array of subjects that are covered by hundreds and hundreds of forums and special service areas, including Electronic Mail, Online shopping malls, airline guides and, of course, computing support forums.

Please login:

Compuserve works more or less like you local BBS – you call it with your modem, login using a User ID and a password, and then use the menus to navigate around. To access Compuserve, you’ll have to have a terminal of sorts (PC, Mac, Unix terminal with CU, etc.), a modem and a credit card. You will also need a phone line to either call the USA direct (rattle, rattle, more cash down the bit-bucket) or an account on INET or GPSS. Assuming that you have all these, all you need to do is connect to Compuserve, and register. One of the easiest ways to register is through the ZiffNet gateway. To do this, set your modem to 2400/1200 bps, Space parity, 7 databits and 1 stopbit, connect to INET or GPSS, enter your password and account number followed by the Compuserve NUA. On INET, this means entering “Npppppp,uuuuuu-03132″, where “pppppp” is your INET password, and “uuuuuu” is your account number. On GPSS, enter “Npppppp-3132″. When the connection to Compuserve is established, enter “CIS” at the HOST prompt, “177000,5000″ as User ID and “PC*MAGNET” at the password prompt. When asked for the agreement number, enter “Z11D9200″. Enter the information that will be asked off you, and have your credit card ready (VISA or MasterCard). You will be registered and given a User ID, and about a week later you will receive an access password by post, after which you can get on with the show. Another way is to ask someone in the USA to pick up and send you a Compuserve starter pack (about $25), which gives you a direct Compuserve account without having to go through the ZiffNet gateway. Compuserve steadfastly refuses to offer pre-paid accounts, so unless you have a credit card valid in the USA (or have access to a card of an obliging friend or relative in the USA or Europe), you can skip the rest of this article and get on with reading the ads. This credit card business rules out virtually every aspirant in India, thanks to our government’s rigid foreign exchange policy. Booo!

The Bill, please:

Compuserve has two billing methods – the Standard and the Alternate Billing Plan. Under the former, you pay a fixed charge of $8.95 per month for the use of certain basic items, such as Electronic Mail, some reference areas and areas included under the Standard Plan. Provided you utilise only these services, your Compuserve bill will be $8.95 a month. If you stray outside these areas (as you will, believe me – ALL the interesting forums are outside the Standard Plan), you pay $8.00 per hour while you are in these areas. The Alternate Plan has no fixed charges per month, but you pay $12.80 per hour online. Unless you specify otherwise, you will be billed under the Standard Plan when you join, and there should be little reason for you to change that. If you are accessing via the ZiffNet gateway, you pay and additional $2.50 per month under either plan. Some areas on Compuserve are “Premium Services” that carry an additional charge. For example, you pay $1.50 per magazine article that you request from the Magazine Database. Finally, if your credit card is not issued by a bank in USA (for example, if it is issued by a bank in Europe), then addition $10 per month will appear on your bill to cover international transaction charges. Please note that all these are Compuserve’s usage charges – the factor not covered under this is your communications charge, i.e. your phone bill if you call direct ISD (Rs.1.10 per second), or your INET/GPSS bill (Rs.200/64KB plus Rs.4 per minute). And these charges are the ones that are really going to drive you bankrupt! The recent hike in Indian Telecom Tariff doesn’t help, either.

You’re on!

OK, assuming that you now have a Compuserve account of your own, let’s see what we can find there. Before you go online, a word of caution – time is money. Turn on your communication software’s capture facility (Alt-F1 in Procomm, Alt-L in Telix, Escape/CA ON in Crosstalk). Don’t spend your time reading online, let it all flow into the capture file, then log off and read it at leisure. A good way of keeping your bills down, even if you are calling a BBS. Like I said earlier, Compuserve works more or less like your local BBS. But this “BBS” is much more than a single line host running in someone’s home or office. At any time, you’ll find hundreds and thousands of users from across the planet online with you. Make the “mistake” of asking for a list of available forums (specific interest areas), and you’ll be treated to a list of hundreds of such areas, ranging from Apple Computer Support through Human Sexuality down to Zen and The Art of MotorCycling. (An uptodate list is available on my BBS, call in and pick up CISAREAS.ZIP from the PCQ or COM forum libraries). In the list, you’ll find virtually every computer oriented organisation worth its salt, including IBM, Microsoft, Lotus, Novell, Borland, Apple, NeXT, TurboPower, and many, many more. Compuserve’s Electronic Mail facility is also very powerful, allowing you to send mail to not only Compuserve users, but also to other networks, such as most Internet sites, MCI Mail, many X.400 services such as AT&T Mail, and more. You can also send fax and telex messages worldwide. Massive databases are at your disposal, including the Official Airlines Guide (OAG), online encyclopedias, magazine databases that contain virtually EVERY article published in the past 10 years, and many more. An online “chat” area called the CB (Citizen’s Band) simulator allows you 40 channels that you can access to “talk” live with thousands of people on as many subjects. One of the most interesting areas for first time CIS users is an area called IBMFF (or MACFF if you are a Macintosh user). This area catalogs the hundreds or thousands of files that are available in the CIS forums. Search on a keyword for something that is of interest of you, and you are bound to come up with at least a couple of choices. Try the keyword “shareware” and you are going to get flooded – most of the files available on CIS are either free or shareware.

Foraging in Forums:

When I first joined Compuserve, it was primarily for the use of its E-Mail services, but soon I was seduced into hopping outside the scope of my Standard Plan’s “Basic Services” and go scouting around in the forums. Being a software developer, the first forums that caught my attention were the developer support forums of Borland, IBM and Microsoft. Each of these companies maintains five to ten forums on Compuserve to service various aspects of their activities. For example, Borland has the BPASCAL (Borland Pascal), BCPPDOS (Borland C++ under DOS), BORAPP (Borland Applications) and dBASE forums, amongst others. Each forum is again divided into “sections”, with each section dealing with various sub-topics. For example, the BPASCAL forum has “From Borland”, “TurboVision”, “Windows Programming”, “Vintage Pascal”, etc. Each section, in turn, has a message and a library section. The libraries are the ones that are going to catch you attention when you first come in through the door – thousands of vendor and user supplied files! If you are human, you are probably going to try and download every item in sight, and this will probably continue until you get your first CIS and Phone/GPSS/INET bill, at which point you will spend a lot of time trying to pay the latter, foregoing less important things like food, water and shelter. After you have got past you initial “download frenzy”, turn your attention to the messages posted in forums, because this is where the true value of Compuserve lies.

The Soul of Compuserve:

“How do I…”, “What is…”, “Where can I find…” Questions, questions. And each one is likely to get a dozen answers, from vendors, users or bystanders. Almost immediately. Yes, this is really where Compuserve shines. The forum message sections. This is where you go when you have a problem. Post your question, and you are likely to be inundated with answers. Try getting the same effect by calling you local vendor for support. What a contrast! The soul of Compuserve is its users, and the fact that they are always ready to help out, no matter how arcane, complex or silly your problem may be. People spend their time and money helping YOU, a person they have never met before, a complete stranger. No “Indian Crabs” syndrome here. One of my first attempts at getting help on Compuserve was when I ran into a problem with Turbo Pascal 6.0 – one of my libraries simply stopped functioning when I switched from TP 5.5 to 6.0. I posted my problem in the Pascal forum, and “went home”. When I logged in later that day, I had dozens of replies, complete with explanations, sample code and pointers to further references, all supplied by users from across the face of planet Earth. If I would have tried to solve the matter myself, I would have spent days, if not weeks or months, trying to resolve the issue. But via Compuserve, my problem was cleared up in under a day. As a matter of fact, the first replies had started pouring in within minutes of my posting the question! This phenomenon is not unique. On Compuserve, every user logging in is a potential support person. It may be that the user had faced a problem before and got an answer, and now he or she, in turn, does his “good deed for the day” by helping you out when you face the same problem. The willingness of Compuserve users to help is incredible! Lord Baden Powell (founder of the Boy Scout movement) would have approved, and would have definitly been a Compuserve user.

Getting the most out of Compuserve:

Compuserve (and INET/GPSS/P&T) make their money out of your presence online – the longer you stay on, the more you pay. In my first few months on Compuserve, I used to regularly rack up around $200-$300 a month, because I was going around doing things manually. Today, my average Compuserve charge per month is about $40-$70, yet I am doing more online than ever before. How do I achieve this ? Simple – I use an automated program to do all the scanning, downloading, posting and reading for me. This program is another pointer at the attitude of Compuserve users. OzCIS (as the program is called), is a “gift” from Steve Sneed, a TurboPower programmer, to Compuserve users – a massive, comprehensive and easy to use program that does almost everything for you automatically, spending the least possible time online. And here is the miracle – it is completely free. Yes, not even shareware – it is free! OzCIS works by accepting all message and file requests from you before you call, then goes online, does all the work, then logs off and lets you savour the results. It is very reliable, and is the “navigator” of choice by thousands of Compuserve users. On Compuserve, it bypasses menus and works in command mode, and option available on Compuserve. Since no menus are used, less characters flow down the line, further lowering your bill. (OzCIS is also available on my BBS. Go to the COM forum and download OZCIS1.ZIP, OZCIS2.ZIP, OZCIS3.ZIP, OZCIS4.ZIP and OZTOOLS.ZIP. The last file contains some utilities and scripts written by me for Indian OzCIS users to make it work properly with INET and GPSS. Like OzCIS, they are also completely free). Compuserve itself offers a program called CIM (Compuserve Information Manager), but it is slow, and favours Compuserve, i.e. it tries to keep you online as long as possible. Though quite easy to use, I wouldn’t recommend it to Indian users. CIM is a commercial product available from Compuserve, and costs about $50. A Windows version has also been recently made available. Yet another Compuserve navigator is TAPCIS, the first of such programs. Though essentially similar to OzCIS in operation, it has a pretty outdated interface and can be quite beastly at times. Besides, it doesn’t work with GPSS or INET. It is shareware, and costs $79 on registration. All the above programs are for DOS and require a hard disk and DOS 3.3 or later, with 640 KB RAM except OzCIS, which works only on 80286/386/486 based machines with 1 MB RAM. All of them are supported online on Compuserve in their own forums. Similar programs are also available for the Macintosh, so Niyam and Ajay (and PKR, of late ) get your hackles down.

Logging off:

OK, OK, I know that I am out of space again. But before I log off, I would like to say that if you can manage to get access to Compuserve, then you will never regret it. If you ever run into a problem, send me E-Mail (my Compuserve ID is 70620,563) and I’ll try and help. Next month, I will cover a few more online services, including BIX (The Byte Information Exchange), British Telecom Gold and MCI Mail. Oh, and before I forget, here is the command for disconnecting from Compuserve: Bye

Login:

My apologies for last month’s “disappearance” from PC QUEST. I got hit by a virus (of the human kind) that kept me non-productive for quite a while.

It looks like my readers aren’t going to let me keep my schedules. In June I talked about about Compuserve, and briefly touched upon Electronic Mail (as I have done in previous articles). Promptly my mailboxes are full again, this time with requests for more details on E-Mail.

OK, so let’s talk about E-Mail.

Making History:

One of the most mundane and irritating duties of my secretary is taking messages for me. A call comes in, it is for me, and I am not there. So she takes a message, which asks me to call back. I get back, return the call, and find that this time THAT person isn’t available. So I leave a message…

What I have just described is known in Corporatese as “Telephone Tag”. In future generations, it will be clubbed in historical essays with AIDS and taxes as a factor that led to the downfall of modern civilisation.

Many times, my secretary tells the caller to “leave an E-Mail message if it is urgent”, to which (at least for now), the caller more often than not replies “uuuhhh – E-Mail???”

Changing norms:

In this age of computers, the very least you’d expect is that computers are smart enough to take a message for me, keep it private, forward it to me whereever I may be in the world, and carry back a reply.

Surprisingly there is such a way of communication, and it is called Electronic Mail (or E-Mail).

It works in a ridiculously simple fashion – you use your PC and modem to connect to the E-Mail service, leave a message in my account, and quit. I will call in 3-4 times a day to check for mail from whereever I may be, find your message, read it and reply in the same fashion.

The beauty of this all is that neither party needs to know where in the world the other one is. And, because only I can read the messages sent to my account, messages remain completely private.

This definitly beats the Fax and Telex (or even telephone messages) which require you to know my exact location, and also will not keep the message private (since anyone can read an incoming Fax or Telex message).

It is hardly surprising then that American business took to E-Mail like a fish to water. And now, in a more leisurely fashion, Indian business too is getting in on the game.

The advantages of E-Mail:

As I have stated before, one of the biggest advantages of E-Mail is the fact that neither the sender nor the recepient need to know where the other is located. This completely and permanently kills the dreaded Telephone Tag Syndrome that is bogging down Indian business.

Secondly, it is much more private than a Fax message, since only the intended recepient has access to the message.

Thirdly (and probably of most importance) is the fact that E-Mail, if properly used, is likely to be much faster and convenient than postal mail or even a Fax. This is because the rerouting of a verbal, written or faxed message in itself will take time to reach the addressee, while an E-Mail message remains in a fixed place, and the recepient knows that any message meant for him will be available at this location, so there is only one place to check.

Getting into E-Mail:

There are primarily two ways by which you can get into E-Mail – subscribe to a commercial E-Mail service (such as MCI Mail, Compuserve, etc.) or set up your own.

The first option if probably the most convenient, since you are likely to achieve the widest reach. A service such as Compuserve is used by hundreds and thousands of people, so it is very likely that your intended correspondent already has an account there. Also, most commercial E-Mail services have gateways to other mail services. For example, from Compuserve, I can send mail to MCI Mail, InterNet, AT&T Mail, etc., and can also receive mail from these services.

The disadvantage is that unless you have access to a Dollar account, it is going to be difficult getting onto one of these services. Though one or two E-Mail services in India are just beginning to get active, it is going to take a long time before any of these come up to scratch. The ones that I know of here are more or less just electronic courier services, and are not very convenient to use. But I suppose things will improve. If they don’t, then I guess I’ll have to do something about it…

A cheaper way of getting access to e-mail services is using the InterNet – a massive, international network of computers linked to each other that are theoretically supposed to service educational institutions, but are also “mis”used by non-educational entities (like me, for example). To get access to InterNet e-mail services, you have to get an account with one of the many educational institutes that have InterNet access. Once you do, e-mailing is essentially free, but getting an account like this is extremely difficult.

Rishab Ghosh covered InterNet in an excellent article in the June issue of PCQ (CyberSpace) – check it out for more details on InterNet. You can also pick up the file INTERZEN.ZIP from my BBS – it contains the text article “Zen and the Art of InterNet”.

Rolling your own:

The other option is to set up your own, private E-Mail service.

This is probably the only way to fly if you are part of a large organisation an have a lot of intra-office messaging. The advantage is that things will really remain private (i.e. it is unlikely that the Government is going to read your mail), convenient (since you can setup things to suit your company’s requirements rather than having to adapt to someone else’s idea of E-Mail) and cost effective.

There are a number of schemes that you can use to set up your own mail service – all of them involve modems. There are BBS-like solutions that have a central host (which have the advantage of being location and operating system independant), and there are point-to-point solutions (which DO have the disadvantage of having to know where the recepient is located).

One thing is clear, setting up your own E-Mail network is not a black art anymore – in most cases, all it involves is calling the vendor and asking him to install the thing for you. (It does involve a minor detail like paying for it, though…)

Using E-Mail:

Using E-Mail isn’t any more difficult than using a WordProcessor.

If you have problems using a WordProcessor, maybe you should consider learning to use one – even if you are the boss of the company and tend to say “I have people to do this for me”. Remember that the “people who do this for you” then also read your private mail, so no one will send you any.

You get online using your modem and communication package, supply your user ID and password, put in your message and the user ID of the intended recepient, and get off.

There are a few tips, though, that will make the use of E-Mail easier:

- Don’t type your message online: Many people tend to do this, and it is stupid. The editing facilities available on most E-Mail services tend to be awkward – why fight them ? Use your text editor (like Teddy or Norton Editor or WordStar in non-doc mode) to prepare your message beforehand. Take your time to make the message worth reading. Then, when you are satisfied with it, save it, call the E-Mail service and, when asked to type in your message, simple use your communication software’s ASCII upload feature to send the prepared message (in Procomm, press PgUp, then select ASCII). Much faster, much more convenient.

- Don’t read messages online: Another weird habit – just because you are online doesn’t mean that you should do everything online. Reading online wastes connect time. Instead, open a capture file before calling the service (in Procomm, press Alt-F1). Everything that appears on your screen will be saved in that file. Now ask the E-Mail service to display all messages to you non-stop. Things will flow past you faster than you can read, which is fine. After all messages have been shown, log off, then read the captured text file at leisure without having “your meter down”.

- Delete messages after receiving them: People tend to be packrats – they never throw anything away. Similarly, people tend to keep all their messages in their Electronic Mailboxes because “they want to refer to them later”. While the argument is fine, the method is wrong. Most E-Mail boxes have finite limits to storage capacity (for example, on Compuserve, you can have no more than a 100 messages pending). Instead of keeping all the messages online, capture them in a text file (as shown above), then delete them from the mailbox.

- Keep using it: I know of many people who have e-mail accounts, but never use them, or at least use them very rarely. This has the negative effect of discouraging your correspondants from using e-mail to contact you. Make sure you check your mail at least once a day, and to reply promptly, even if it is just to say that you will be replying in greater detail soon. If people know that you use your e-mail account regularly, they will use it to contact you, thereby giving you all the benefits that e-mail has to offer.

- KISS!: This (modified) acronymn stands for “Keep it short and simple!” and is, in effect, the guiding rule that governs effective emailing. When you send a message, be concise and to the point – don’t repeat yourself over and over again and make your point in the clearest and shortest manner. If you are replying to a message, make it a point to quote from the original message (easy to do with cut’n'paste) in your message before making your reply – this way the reader will be able to keep track of the context without having to refer back to his own message, which may have been sent some time earlier. For example, supposing you are replying to a message that extolls the merits of email. Your reply would look something like this:

> I think that E-Mail is a very effective medium of > communication. What do you think ?

I agree completely. Without E-Mail, things would be very difficult…

In the above example, lines beginning with “>” are lines quoted from the original message. Lines without this sign are your comments on the quoted material. This convention is very commonly used and you too should employ it.

- Emote: It is sometimes very difficult to get across the actual meaning of a sentence using e-mail. For example, if I say “PKR is too miserly to buy a modem” it will probably cause a rift in my relationship with him, but if I say “PKR is too miserly to buy a modem ”, he will know that I am saying this tongue-in-cheek.

In case you haven’t understood this – look at the “:-)” sideways – it is a face smiling at you. This is called a “smiley” or “emoticon”, and there are thousands of them available that can give your messages the right flavour. For example, here is the emoticon for a bespectacled man smoking a cigarette, whose hair stood up on seeing his latest phone bill:

=B-Q

Pick up the file EMOTICON.TXT from the PCQ forum on my BBS for more samples). Usage of emoticons will avoid unintended insults or hurt feelings.

Getting the word out:

Email is catching on all over the world and is today the preferred way of communication. But how do you let people know that you have an e-mail address ?

Actually, that is simplicity in itself. Display it prominently on your letterheads and visiting cards (and even fax messages). Most mail services can be addressed in the InterNet fashion. for example, my Compuserve ID is 70620,563. To send me mail via InterNet from any other service (such as MCI, America Online, ERNET, etc.), just send the message to achitnis@exocore.com. This address appears on my visiting cards and correspondence, and you will be amazed if you would see how many people prefer to communicate with me this way !

Logout:

OK, I am out of space again. But before I sign off…

In my June article on Compuserve I had mentioned the program OzCIS, and that it is available on my BBS. Steve Sneed (the author of OzCIS) has informed me that he is releasing a new version on or before July 15th. Because of this I have temporarily taken OzCIS off the board to prevent you from blowing major money on downloading a soon-to-be-outdated program. The new version will be available for downloading by 3rd week of July.

Also, I have been receiving TONS of mail (e-mail and snail-mail) from my readers. I try to answer ALL my e-mail, and even some snail (postal) mail, but there are limits to how much of my professional time I can spare. So please understand if I cannot answer every letter or message personally.

The “recommended” shareware of the month is FONEBOOK, a phonebook-cum-dialler written by Varun Arora of Bombay. Neat. Keeps track of names and addresses, and dials the phone number if you have a modem attached. Can be found on most BBSs around the country (including mine).

Finally – this month I will NOT tell you what I am going to write about next month ! Make sure you get your PCQ issue as it hits the stands if you want to find out ! (Take this seriously – I have had to STEAL a copy for the past few months because they are sold out within a day of appearing on the stands!)

Ciao for now !

In this issue, I am going to talk about File Transfer Protocols. This particular article is going to be a wee bit technical, but I’ll try to make it as human as possible.

What is a File Transfer Protocol ?

Many times you will need to send or receive information that cannot be handled using a text based message. Examples of this are data files, programs or any other kind of file that are not text based.

Unlike text messages, binary files cannot tolerate even the slightest error or anomaly. To explain this, let us take the example of a simple message :

Deer Raju,

Hi! hou arre yoo ? Deed yu geth de letyer Aih sended yastrdey ?

Rply suuuun,

Atul.

In the example shown above, it is fairly obvious that the writer (in this case me, and this is an example – I was NOT sleeping during grammar and spelling classes at school) has made some gross errors in both spellings and grammar. Yet the message, once received by the addressee, will carry its meaning across, inspite of all the errors. This is because the interpretation of the message is left to the human brain, which is much more accomadating (or fault tolerant) than a computer can ever be.

But take the example of a binary program that, let’s say, reads and displays sectors of a disk. It uses the DOS interrupt 25H to read the sector, and then displays it to you. By itself, this represents a relatively innocent and safe utility program, but if it is even slightly altered, it can be a potential monster. If this program, sent over the telephone line using modems, gets “hit” by line noise or interference (as described in the first of these articles), then a simple bit shift can turn the Interrupt 25H instruction into Interrupt 26H. This is fatal to the user of the program, because Interrupt 26H does not READ from a disk sector, but WRITES to it, and the innocent program you sent potentially can wipe out the addressee’s hard disk !

Or take the example of a database file that contains salary information. A single hit, and Mr.ABC’s salary for the next month suddenly jumps a hundred fold, causing losses to the company ! This is not too uncommon, and you yourself may have experienced it if you have ever sent a fax or telex message that got garbled.

To prevent this sort of thing from happening, we use a system called “Protocol Driven File Transfers” involving “Error Detecting and Correcting Methods”. In plain English this means that a File Transfer Protocol lets you transfer files without a chance of an error creeping into the file. If one does creep in, it is detected, and corrected.

A file transfer protocol is an agreed upon method or set of rules (between the sender and receiver) of transfering file information. These rules, unique to each protocol, form the basis of the comparitive strengths and weaknesses of differing communications protocols.

There are literally hundreds of file transfer protocols used today, but the most common ones are XMODEM, XMODEM-1K, ZMODEM, YMODEM BATCH, YMODEM-G BATCH and KERMIT.

Most good communication packages support all the above mentioned protocols, both for sending as well as receiving files.

Selecting a Protocol

Any file transfer begins with your selection of File Transfer Protocol (FTP) that you wish to use. Naturally you must choose a FTP that is supported by both sides of the connection.

Which transfer protocol should you use ? There is no definite answer to this question, but there ARE some guidelines which you can follow :

1. First of all, check which of the protocols is supported by your communication program. You can determine the FTPs available in your communication program by going through its manual. If you are using ProComm, hit to see a menu of available protocols.

2. What is the line condition like ? If you are NOT using an error correcting modem, and frequently see junk on the screen, then it is advisable that you use either of the “short packet” FTPs, i.e. XMODEM or KERMIT. Though the throughput of these FTPs is less (slower) than that of XMODEM-1K, YMODEM BATCH or ZMODEM, they provide faster error recovery.

3. Are you calling using a 7 bit line ? Normally you shouldn’t, because most Communication Hosts specify that you should call using 8 bits no parity, but in some cases using a 7 bit setting may be unavoidable, such as when you are calling from a mini computer terminal or your communication software does not permit anything else. If you ARE calling at 7 bits, then you have only one choice – KERMIT, which is the only FTP that works on a 7 bit connection.

4. Are you calling using an error correcting modem ? If yes, then the high-throughput FTPs XMODEM-1K, YMODEM BATCH, YMODEM-G BATCH or ZMODEM should be used. Since the chances of an error occuring are remote, these FTPs allow you to push through larger data packets, speeding up the process immensely.

OK, now that you have decided which protocol you wish to use, indicate your choice to the remote host (who usually shows you ITS available protocols in the form of a list or a menu).

What happens next is dependant on the choice of FTP, the operation (upload/send or download/receive) and the procedure from where the file transfer was initiated.

Transferring a File

If the transfer involves a download (receiving a file), then the remote host will almost always ask you for the name of the file you wish to receive (unless there isn’t any choice, since there is only one file).

If the file requested is found, then the remote host will ask you to initiate your receive procedure using the specified protocol, and will await your start signal. At this point, you can usually abort the transfer by pressing a couple of times.

To initiate the transfer at your end, you have to instruct your communication package to begin downloading the file with the matching protocol. If you are using ProComm, then hit and select the same protocol as you have instructed the remote host to use. (If you are not using ProComm, you can determine the exact procedure from your communication software manual.) In the case of either of the XMODEM FTPs, you will have to tell your program what file name to use at your end, while the YMODEM BATCH, YMODEM-G BATCH, KERMIT and ZMODEM protocols do that automatically for you.

Now you will usually see a status screen on your terminal, telling you about the progress of the transfer. The actual transfer should begin within 1-10 seconds. If it does not, then something is wrong, and you will have to cancel the transfer.

Once the transfer begins, you will see the number of blocks of data that your computer has received, and the error status. Don’t be worried if you see errors being reported. This is actually a positive sign – it means that the FTP has detected an error, and is correcting it ! Of course the non-appearance of errors is a good sign, too.

After the transfer completes, your communication program will tell you so.

That’s it ! The file has been successfully transferred ! If it has not (because of excessive or fatal errors, or because you chose to abort the transfer), you will usually be given an option to retry. Answering “YES” will restart the process from the point of the FTP selection, answering “NO” aborts the process and returns you to the calling procedure.

More about File Transfer Protocols

Although each file transfer protocol differs in the specific rules that it follows in transferring information, all FTPs have certain similarities:

* Each Communication session begins with an initialization state where the receiver and sender establish the specific method of information transfer. (Techno-jargon that means that both sides agree on which “language” they are going to speak in)

* The contents of a file are transmitted in the form of packets or frames of an agreed upon format.

* All of the protocols are “stop and wait” protocols where after sending a packet or frame, the sender stops and waits for a response to the sent packet. Ymodem-G Batch and Zmodem are exceptions to this – they blast data across “full throttle” unless specifically told to pause by the protocol at the other end.

* Each packet or frame has a Start-of-Header character or sequence which indicates to the receiver the beginning of the packet or frame.

* Each packet or frame is uniquely identified by a frame number or sequence number.

* The integrity of the frame or packet is assured through the use of an error detection code typically placed at the end of the packet or frame.

* The packet or frame contains a data portion which is the file information being transferred.

Like I said, the basic reason for the use of a file transfer protocol is to maintain the integrity of transmitted and received data. Since all communications may be subjected to noise or other data corrupting forces, use of a communication protocol will insure that all information is transmitted and received error free.

Let’s take a closer look at each of the common protocols.

XMODEM and XMODEM-1K :

This protocol is the “grand-daddy” of them all, since it was the first one ever to appear for general usage. It was conceived and developed by Ward Christiansen in the late 70′s, and gained rapid popularity because of its straight-forward implementation, and wide spread support on many BBSs.

XMODEM is receiver-initiated – both the receiver and sender computers are aware of the file transfer. XMODEM is generally used to download a file from a host to a user’s PC that is operating as a terminal emulator. File name is not preserved and receiver and sender must both specify the file name of the file being transfered. File length is not preserved and is padded to the nearest 128 byte (XMODEM) or 1024 byte (XMODEM-1K) increment.

The XMODEM session begins with an interchange of initialization characters in order to establish the format of the data transfer. Once the session has been initialized, the sender begins transmitting information starting with frame number 1. The session progresses with the sender transmitting a data frame and the receiver responding to the data frame. Upon successful transfer of the last data frame, the sender indicates to the receiver that the session has completed.

YMODEM BATCH :

YMODEM BATCH is a receiver initiated protocol. Essentially, it is an embellishment of the XMODEM-1K protocol which provides CRC error detection. It can use 1K data blocks, multiple files can be transferred within one session, and both the transfered file name and exact file length are sent to the receiver.

Like XMODEM, the YMODEM BATCH session begins with an interchange of initialization characters in order to establish the format of the data transfer. Once the session has been initialized, the sender begins transmitting information starting with packet number 0. Packet 0 contains the file name and (optionally) the file length information of the file data to be transferred. The session progresses with the sender transmitting a data packet and the receiver responding to the data frame. Upon successful transfer of the last data packet, the sender indicates to the receiver that the session has completed.

Since the filename of each file being transferred is preserved (from sender to receiver), the receiving YMODEM BATCH session need only specify the destination drive/directory for the path argument of the YMODEM BATCH receive function calls.

YMODEM-G BATCH :

This is probably the fastest possible file transfer protocol that exists today.

YMODEM-G BATCH is, essentially, an embellishment of the YMODEM BATCH protocol which provides CRC error detection, 1K data blocks, multiple files transferred within one session, and preservation of both the transfered file name and exact file length. In addition, this is a “flowing” protocol, especially meant for the use with Error Correcting (MNP) modems.

YMODEM-G BATCH is almost identical to YMODEM-BATCH, but in the case of YMODEM-G BATCH, the receiver does not respond to the data frame, unless an error takes place, in which case the protocol is aborted.

KERMIT :

The Kermit file transfer protocol was developed in 1981 by Frank da Cruz and Bill Catchings at Columbia University in order to facilitate the transfer of information between mainframes and PCs.

Kermit provides for multiple files to be transferred within one session and for preservation of both the file name and exact file length. It also allows for communication to take place on both 7 and 8 bit communication channels (This is accomplished via the 8th bit prefixing option. Any 8 bit data is prefaced with a special character that tell the receiver to treat the next character as an 8 bit byte).

Kermit transfers all information in the form of packets. After a packet is sent, Kermit will stop and wait for a response (in the form of a packet) before it sends the next packet. All Kermit packets are composed of printable characters

Kermit packets can be a maximum of 96 bytes in length and use the 8 bit folded into 6 bit checksum error detection method to insure data integrity.

This is the only protocol that can be used to transfer binary data over 7 bit lines, but does have the disadvantage of being less throughput efficient than any other protocol.

ZMODEM :

Zmodem is sometimes referred to as the “King of FTPs”, and with good reason. It can do things that almost no other protocol can do, such as receover from a crash, by continuing the transfer from the point where the transfer failed, rather than sending all the data once more.

Zmodem also has a unique “Auto Download” feature, that automatically starts the transfer at the receiver’s end (provided this feature is enabled at the receiving end).

The protocol was developed by Chuck Forsberg, a developer at a company called Omen Technology, on request of the carrier network giant Telenet, for a very specific purpose : to overcome the pitfalls of packet switching networks.

Packet switching networks are data links similar to telephone lines, but specific to computer communication. They too use a form of data packetisation, which interferes with the functioning of normal file transfer protocols. (More on packet switching networks, including I-NET, in my next article).

Omen Technology developed the protocol, which was later placed in the public domain by Telenet.

Zmodem, like Ymodem-G Batch, uses the streaming style of data transfer, i.e. it doesn’t wait for an acknowledgement of a packet before sending the next one. But unlike Ymodem-G Batch, it recognises error messages from the receiver, and takes action to rectify the problem.

Winding Down

Woops, out of space again ! (How words fly)

OK, my apologies about the “techno-junkie” feel of this article. Next month, I look at various ways to broaden your horizons, including BBSs and Carrier Networks – in particular I-NET, India’s premier network.

Till then,

Ciao !

This must have happened to all of us at some time or the other while using a modem:You are transferring a file, the error count keeps building up, and finally the transfer crashes. Bad line ? Not necessarily. As a matter of fact, it could be too good a line that’s causing the problem. Data could be coming in too fast to be handled by your computer !

What’s faster – your 486 or your serial port ?

Ever sat through a file transfer that seemed to take forever for even a small 100 KB file ? And, to make it worse, after the transfer was over it took just two seconds to copy the same file from one disk to another ? Can anything be slower ?

And yet it is possible for a modem to run faster than your computer can handle it !

Modems have always been rated very low in terms of speed, and saying that a modem could “outrun” your computer would bring pitying smiles on the face of the listeners. “Outrun my 486 based, 33 MHz, Cache RAM based super desktop ?” they would say.

After all, a modem typically works at 2400 bps, or 240 bytes per second (in asynchronous communication, 10 bits are required to transfer a single 8 bit byte). How can something as slow as that be faster than even a 4.77 MHZ PC ? Ridiculous !

But think again, friends. There are darker sides to your PC that make it an ideal target for “Comm Overruns”. You don’t believe me ? Well, read on, and be prepared for some surprises.

The Dark Side of the Moon

The PC (whether 8088 based or 80486) communicates with your modem via its serial port. This includes internal “modems-on-a-card”, which typically have serial port circuitry onboard, but suffer from the same serial port problems as an external modem nevertheless. And this serial port functions on the principle that it receives one character from the modem, then waits for the PC to pick up that character, thereby clearing the way for the next character. This includes internal “modems-on-a-card”, which typically have serial port circuitry onboard, but suffer from the same serial port problems as an external modem nevertheless.

Should a character arrive from the modem when the earlier character has not yet been picked up by the PC, then we have an overrun.

“OK, but why should the PC not pick up the character waiting in the serial port’s buffer ? After all, the PC is thousands of times faster than the fastest speed that the serial port will work at !” says the sceptic.

True, a PC is much faster than its serial port, but there is a catch – a PC is sometimes not free to service the serial port. And just like even a Ferrari Formula 1 racing car cannot win a race if it doesn’t even participate in it, the character waiting at the serial port can get overrun because the PC isn’t checking for that character.

“How come ?”

To explain that, I’ll have to give you a bit of background on how communication software deals with the serial port.

May I interrupt you for a moment ?

Modern communications no longer works on the basis of “polling” (checking every now and then) the serial port for characters. Instead, it relies on interrupts from the serial port to inform it that a character is ready to be picked up. This is much faster than polling, and is the way 99% of modern communications programs work.

To understand this, picture yourself sitting in an office, with a phone by your side. Now the phone is a useful thing to have, but its utility would be severely curtailed if you had to pick up the receiver every now and then to see if there is a call coming in.

Naturally, the phone has a way to tell you that there is a call waiting to be answered. It rings a bell. So you stop whatever you are doing, pick up the phone and talk. If the phone doesn’t ring, you know that there is no call, and can go about doing something else.

The PC’s communication interrupt mechanism works in a similar fashion. Instead of constantly checking the serial port, the PC relies on the fact that when a complete character has been received and needs to be picked up, the serial port sends an interrupt to the CPU, effectively tapping it on the shoulder and saying “Hey ! Could I have your undivided attention for a moment ?” The CPU passes this signal to your communications program, which in turn picks up the character from the port.

Unfortunately there are instances when the PC “takes the phone off the hook” for a while by turning off all interrupts, thereby making it incapable of receiving an interrupt from the serial port. If this happens, the CPU never realises that there is a character waiting to be serviced, and as soon as the next character comes in, it kicks the original character out of the buffer, causing data loss.

Paradoxically, the most common of such instances is when the PC is accessing the disk ! When this happens, the PC’s BIOS turns off all interrupts until the disk access is complete. And if this happens for long enough, we get overruns at the serial port !

How long is “long enough” ?

Assume you are receiving data at 2400 bps from the modem. This means 240 characters per second, or one character every 1/240 of a second. So, the first character is ready after 0.004 of a second, the next one is there after 2/240, or 0.008th of a second. And that, my friend, is your “long enough” time. If your PC hasn’t picked up the first character by the time the second character is fully received, then an overrun takes place !

Now just take a typical disk access. Assume that you are receiving data and, after every 1024th character, are writing this data to disk. The instant you start writing to disk, the PC turns off all interrupts, and begins the write operation. Now, if your hard disk is slow, this can take as long as a second (longer if the target is a floppy disk). That means that your PC could be “out of action” long enough to lose upto 240 characters !

Haven’t had enough yet ? Consider that most modems today are MNP or V.42 modems, and are capable of operation at 9,600 to 34,000 bits per second, the “time out” is shortened radically ! If you take as an example a modem delivering data at 9600 bps to your PC, then the “long enough” time is 2/960th of a second ! Want to really fall into depressions ? Try 34,000 bps on your calculator !

The Electronic Traffic Cop

OK, enough of doomsday. Now that you know WHY overruns happen, let’s see what we can do about it.

Actually, the matter is simple. Just tell the modem to stop sending data for the duration of the disk write.

“Aha !” you say “send an XOFF (Ctrl-S) to stop the flow !”

Nice try, my friend, but no cigar.

If your modem (or the remote source of the incoming data) is set up to recognise XOFF as a “hang on a sec” signal, then a spurious XOFF (caused by line noise or even program error) can send your communications link into limbo. Besides, sending an XOFF takes too long, anyway. And if you are transferring binary data such an EXE file using something like YMODEM or XMODEM, an XOFF that is part of the data can be misinterpreted as an error.

The answer lies in the very definition of the serial port’s signals. If you have a description of a serial port’s signals in front of you, you’ll see that two of the pins are marked as “RTS” and “CTS”. On a standard 25-pin serial port, they are pins 4 and 5. Now there must be a reason for these signals to be there in the venerable CCITT’s recommendation of RS232C. And there is. These signals are known as the “hardware handshake lines” or, more commonly, as the “hardware flow control” lines.

The RTS and CTS signals are interpreted as follows:

When the PC is ready to receive data, it raises its RTS (Request To Send) signal. This causes the CTS (Clear To Send) signal of the modem (or remote device) to be raised, indicating that it is safe to send data.

If the PC needs to halt the flow in order to do something like a disk write, then it lowers the RTS signal, which causes the remote CTS to drop, telling the sender to “hang on while I do something”.

Since the RTS and CTS signals are not part of the data stream, they are transparent to the actual data flow, and do not interfere in any way, making them ideal for purposes of flow control.

Using Hardware Flow control

So how do you implement it when using your communications program (such as Procomm or Crosstalk) ?

Easy enough. Just enable this hardware flow control setting in the program’s setup. And make sure that your modem is set up to recognise them, too. In Procomm this setting can be found in the Terminal Setup, in Crosstalk, it is in the main setup screen. While you are there, make sure that you disable software flow control (XON/XOFF) which has no place in high speed communications, anyway.

Secondly, make sure that your serial cable from the PC to the modem has all the nine critical wires connected correctly. Some people have been using three-wire cables for modem communications, which is not enough if we are talking about speeds in excess of 300 bps.

Your modem needs to be set too. On most modems, the AT&R0 setting causes the modem to let RTS and CTS act normally (there may be some jumpers involved). On most MNP modems, the ATQ3 setting will enable the modem’s hardware flow control (on some it is AT&E4&E7). Check your modem’s manual for this.

Now try downloading (transferring to your computer) that king sized file that you have been wanting for so long, but always failed to get because the transfer failed. Voila ! It worked !

Fish ‘n’ Chips

There are some other things you could also do to ensure that your communication session doesn’t cause you grief. One of the most common problems in PCs sold in India is that the serial port chip (known as the UART) on the I/O card is very often not meant for use with that particular machine.

Specifically, all BIOSs written for the 80286 and above expect to find a chip called the 16450 managing the serial port. But some “fishy” manufacturers, in order to save money, use the older 8250B chip. What most people do not know is that the 8250B has a documented bug in it that causes the chip to “lock up” at random when operating at speeds in excess of 1200 bps. Older XT BIOSs were written keeping this bug in mind. But the newer AT and 386 BIOSs were not. That is why you can virtually guarantee disaster if you are using such a chip on an AT class machine.

I use an public domain utility called UARTID (written by TurboPower) that tells me what chip is in use on a machine, but you can also check this out physically by sneaking a peep at the I/O card in your PC. This can be a problem if your I/O card uses one of those “all-in-one” ASIC (application specific integrated circuit) chips, which hide the true identity of the circuitry. In such a case, you WILL need the UARTID utility.

If you find an 8250B chip in your AT class machine, change it pronto to a 16450, and many of your problems will go away.

You could also use the newer 16550AF UART in place of the 16450. This chip has a special buffer built in that avoids port overruns. Many newer communications packages recognise and activate this chip, resulting in almost perfect data flow.

RAMbling on

Finally, a little tip for those concious of the clock when they are online. Instead of downloading onto a hard disk, try downloading onto a small RAM disk. This RAM disk should be about 10% bigger than the largest file you plan to transfer.

With protocols such as YMODEM-G BATCH or ZMODEM, this can make a substantial difference in transfer time and reliability, since the time taken to write to a RAM disk is negligible compared to the time taken to a Hard or Floppy Disk. Because of this, the time that the PC “takes the phone off the hook” is reduced considerably.

Winding down

Oh oh – did someone ask “what are YMODEM-G BATCH and ZMODEM?” I thought you knew about those !

You didn’t ?

Well, they are two of the most popular file transfer protocols in use today, and they, along with other protocols, feature in next month’s column, where I will be talking about different aspects of file transfers using modems, including which to use when and how to achieve the fastest possible transfer times.

See you next month !

Hi there !Welcome to my new column, where I will be addressing various computing issues that concern the end-user, i.e., you.

This month, I begin with the first of a series of articles dealing with modem communications.

A Tale of Bargains

Sometime back, I went to see a friend who was having a bad time. Let me tell you all about it:

This friend recently went on a trip to the Far East. Being a computer buff, always ready to go in for “the latest,” this chappie went in for a modem. “After all, with I-NET and other communication services coming up in India, a modem is a useful thing to have” was his argument.

Unfortunately, knowing nothing about modems, he went the classic route – he bought what seemed a really good bargain. “After all, all modems work the same way” says he.

Famous last words.

When he hit town, he connected everything up as shown in the three and half pages of documentation that accompanied the modem, fired up the pirated communication package that he got with it, and tried to log into my BBS (Bulletin Board Service).

Next morning, I looked at the activity log on my BBS machine, and saw a chaos of failed transfers and junked messages recorded there. I immediately got on the phone to my friend to check what had happened.

“I got all sorts of junk on my screen, and everytime I tried to transfer a file, the transfer got aborted because of too many errors” says my bargain-hunting friend. I told him I’d be right over to see what was the problem.

Reaching the scene of the crime, I flipped through the pages of the manual (which didn’t take too much time, considering its size), trying to find out how to enable the modem’s error correcting feature. It had to be there somewhere . . .

It wasn’t.

My friend had spent his money on a cheap, non error correcting modem. Something akin to buying a bullock cart for the German Autobahn. What had seemed a bargain was in fact a piece of junk.

Cross Connections

If there is one thing that is consistant about India’s telephone system, it is the terrible quality of the lines. Often, a call to a local number feels like a long-distance call to the moon – via Pluto. Cross-connections, crosstalk, clicks, buzzes and beeps are part and parcel of any phone conversation.

Now consider how a modem works. What it does is to take your computer’s digital signal, and turn it into Audio tones, which can be transmitted over the phone line. The receiving modem turns these tones back into digital signals for the receiving computer’s listening pleasure.

Great in theory. Now, just to provide a bit of entertainment to the process, add a heavy dose of “Indian Telephone Line”.

Fireworks ! Special Effects ! Chaos ! Now you know where the director of the movie “F/X” went for inspiration.

Since the receiving modem tries to make sense of every blip, beep and squawk it hears on the line, the noise on the line drives it plain batty.

This is what was happening to my friend’s first attempt at datacomm. Since his modem lacked a way to distinguish between signal and noise, what he got on his screen was his modem’s interpretation of the “symphony” it heard on the phone line.

The fact is – Indian telephone lines are completely unsuitable for unprotected computer conversations. (Actually, I have felt that way about some human phone conversations, too). The line noise caused by outdated crossbar exchanges and rotten trunk cables makes the Indian telephone system a place they send little modems to if they have been bad boys.

So how does one “protect” a datalink from line noise ?

Error Correcting Modems

Picture this :

You are talking to a friend and are giving him a phone number he wanted. Line noise being what it is, he doesn’t hear you clearly, meaning that he doesn’t get the phone number.

So he says “hold it, I didn’t get that clearly, can you repeat that please ?” and you repeat the number until he gets it perfectly.

That is how error correcting modems work. They “packetise” the data being transferred, and add some more data to it that allows the receiving modem to decide whether the data packet is “clean” or has been “hit” by line-noise. If it detects such an error, it asks the sending modem to retransmit the data packet until it gets through clean. This process is completely transparent to the user.

Error detection and correction is a basic requirement if you plan to use a modem on Indian telephone lines. This feature comes in two flavours – MNP and V.42.

MNP is the grand-daddy of error-correcting schemes, and was developed by modem manufacturer Microcom (therefore the acronym MNP – Microcom Network Protocol). Almost every error correcting modem produced today incorporates this scheme.

V.42 is the CCITT’s version of almost the same thing. The CCITT is the international body that decides what is a standard in communications, and what is not. It tags these weird names to their recommendations (such as V.42) that in itself tells you nothing except that it is official.

Anyway, MNP and V.42 are two schemes used for error correcting modems, and they ensure that they can communicate with other modems speaking the same lingo without errors. The two are compatible, and will talk to each other.

But error-correcting modems don’t stop at that. They have another function – data compression.

Effectively, what this means is that the modem collects a packet of data, compresses it, then sends it on its way. The receiving modem decompresses the packet and passes it on to the computer. Since it takes less time to send a compressed packet of data, the effective throughput of data between the modems is increased.

MNP has the MNP5 compression standard (MNP4 is the error correcting part of the protocol), where as V.42 has V.42bis. Unlike the error correcting parts of the protocols, MNP5 and V.42bis don’t talk to each other.

This is also where the old gives way to the new. MNP5 has a maximum compression ratio of 2:1, meaning that the effective throughput of a MNP5 modem running at 2400 bps (bits per second) is at the most 4800 bps.

V.42bis, on the other hand, compresses things down to 4:1, giving an effective throughput of 9600 bps.

The two also differ in how they treat pre-compressed data, such as the contents of a ZIP file. Whereas MNP5 tries to compress every packet of data it gets, thereby wasting time on data that cannot be compressed further, V.42bis recognises the pre-compressed state of the data, and simply sends it on its way without any further waste of time.

Most V.42bis modems also incorporate MNP5, so that if you are calling a MNP5 modem with your V.42bis modem, it will step down to the older protocol. Naturally, the same is not true the other way round.

By now you must have guessed that my friend’s modem had neither MNP nor V.42 error correction – to say nothing about compression.

Modem Vendor Jargon – Tricks and Traps

“This modem has dynamic signal balancing circuitry” says Vendor X, trying to convince me that his modem is just what I needed. When I asked him about error correction, he slunk away.

“This modem is rated for 2400 baud – meaning that you can transfer 2400 bytes in one second !” says Vendor Y. Surprising, I said. I have always thought that “bps” stands for “bits per second”, and that it takes 10 bits to transfer one 8 bit byte, meaning that 2400 bps equals 240 bytes a second. The vendor quickly became a dot on the horizon, fading out.

“This modem works at 1200 bps. Since Indian telephone lines do not support faster speeds, this saves you money because you don’t spend on expensive 2400 bps capabilities that are useless to you” warbles Vendor Z. I just cast a pitying smile on the poor animal, while checking on the progress of the 9600 bps file transfer from Bombay on the V.32/V.42bis modem standing on my desk.

“An internal card modem is much more productive than an external modem” says yet another aspirant. When I eagerly asked him to prove his point by attaching the modem to my Notebook computer (on which I am writing this and which does not have any expansion slots), and then move it to my other machines all within a minute, he politely wished me good day.

“This modem is imported from the USA, and is better than anything available in the Indian market” shimmers the heavily accented salesman. “Great !” I say, “naturally it also comes with the Department of Telecommunications License that allows me to use it on P&T lines without having my phone disconnected . . .”

Where did he go? Probably left before I could ask him about servicing of his modem in India in case of problems.

“This 2400 bps modem actually operates at 9600 bps” gloats another. “Oh Gee !” smiles his tormentor, “let’s try that with this heavily compressed ZIP file”. Is that a bird ? Is it a plane ? Nope, it is just another jargoning salesman beating a hasty retreat.

I think the savvy reader is beginning to see the point I am trying to make. Modems are new to most people, and many modem vendors and their salesmen will try to confuse you with technical jargon that is designed to cover the obvious flaws of the merchandise, such as the lack of Error Correction.

I think this is highly irresponsible, and whereever possible try to get such vendors blacklisted by my clients. To help my clients decide what is genuine and what is not, here is a set of questions that I ask them to place to the vendor (some vendors call them “Atul’s Dirty Dozen”) :

1. Does the modem have error correcting facilities ? (The answer better be “YES”)

2. If yes, what is the error correction scheme that is used ? (Should be MNP or V.42)

3. Does the modem have compression ? (Ideally, should be “YES”)

4. If yes, what scheme does it use (Should be MNP5 or V.42bis. Some vendors use MNP7 – a protocol that was Dead on Arrival and is not used anywhere in the world)

5. What is the modem’s true speed ? (should be 2400, 9600 or 14400 bps, with four times that if using compression)

6. Does the modem have the D.O.T. license for use on the Indian P&T lines ? (Must be “YES”, or you may have your phone disconnected)

7. Is the modem an internal or external model ? (An eternal model has many advantages over an internal one, such as easy mobility, status lights, a voice/data switch, independant power supply, audible speaker, etc.)

8. Does it come with any licensed communication software ? (The answer must be “YES” – modems are useless without communication software, and the software must be legal – piracy is a crime)

9. Does the modem come with any written warranty of at least one year? (If no, you can expect it to fail two days after the invoice is paid)

10. Is the modem made in India ? (Unlike many other electronic devices, Indian modems made by reputable manuacturers tend to perform better under Indian conditions than imported ones, and have the advantage of local support in case of problems. Besides, I am pretty patriotic)

11. Is a comprehensive manual included with the modem ? (You’ll need one to optimise performance and adapt to different situations)

12. Is a serial cable included with the external modem ? (Many vendors try to make this a hidden cost for which they charge you later. Make sure that this is not so)

Get the answers to these questions from the vendor in writing. If possible, ask for a list of references, such as at least five other customers. Check with them about the vendor’s claims of performance and support. If more than 20% of them have complaints, you can expect to join their ranks soon.

Also make sure that the support personnel knows their business. Ask someone from the company to show you how to use the modem, and ask him to demonstrate a file transfer between two of his modems, as well as between his modem and that of another make. If he cannot demonstrate a file transfer, or resorts to the Kermit protocol (a very slow file transfer protocol that places the least strain on the communication link – more on this in a later article), then you cannot expect much support from the vendor when you have problems.

Finally, make sure that you test the modem yourself for at least two days, preferably in the presence of a friend who knows something about modem communications. I have often seen situations where someone blames the bad performance of the modem on his lack of knowledge about such things. This is rarely true.

If you expect the modem to act as a Host Modem that receives calls 24 hours a day all round the year, do not buy the modem if no customer can report long-run performance of the modem. Many modems are likely to fail under such conditions because of component degradation due to heat and power fluctuations.

Winding down

Hey ! Don’t tell me I am out of space already ? I don’t like that evil gleam in my editor’s eye as he advances with his dreaded pair of scissors.

Anyway, to close this piece – my friend bit the bullet and bought a modem locally according to my guidelines. I am happy to report that he not only happily communicates all over the world with his new modem, but is also busy advising people on how to buy a modem.

Next month, I am going to get a bit technical by talking about things like Hardware Flow Control and how it plays an important role in high speed communications. So stay tuned !