Get a Real Modem

By Rich Steiner

Introduction
Some time ago someone had a problem using a cheap 14k4 modem (a Zoltrix 14.4 RPI modem) with OS/2. He mentioned a brand that I'd heard of shortly beforehand in another forum. The main problem is that the modem depends on host software for some of its functionality. The modem belongs to a class of modem loosely called "winmodem." Like winprinters, it requires special Windows software and uses host processing capacity to provide function.

I summarised the discussion saying the consensus of opinion seemed to be, "Get a real modem."

After that, the verbal donnybrook started. The owner of the modem took afront, others leaped in offering various explanations and contrary opinions. Many agreed with, "Get a real modem." Others report that they work well.

Richard Steiner seemed to me to offer the best summary of the problem and has agreed to me publishing it here.

It seems particularly timely as there were a couple of other threads dealing with winmodems about the same time.

Be aware that Richard wrote from memory and didn't do the research he would have had he expected it to have a more permanent life.

js>With Rich's permission, I'll add it to my web pages rs>That would be fine, but these links may provide much better information:
 * 1) http://www.nb.rockwell.com/mcd/bman/rpi_faq.html
 * 2) http://www.aimnet.com/~jnavas/modem/faq.html

There are other sources of excellent information out there, but these will give people some idea of what they're in for if they decide to purchase an RPI modem.
 * The story according to Richard Steiner

Here in comp.os.os2.comm, marco@nbnet.nb.ca spake unto us, saying:

>John Summerfield wrote: > >> I've heard that this is a WINMODEM and does not work with OS/2 just as >>    the WINPRINTERS don't. >> >> The recommendation I saw in another forum is, "Get a real modem." > >I can't believe my ears..."Get a real modem"...How about "Get a real >OS"? Win95 works with it...OS/2 *is* dead. I can't believe how people >just like to give up. It will work, and I'll fix it...you can bet on >that!!!

The problem is that RPI (Rockwell Protocol Interface) modems have part of their firmware implemented as software. It's a cost-cutting measure on the part of the manufacturer, and it may (not always, but sometimes may) introduce some very real software dependencies in a device where no such dependency usually exists (most modems have their firmware completely implemented in hardware and are largely OS-independent).

An RPI modem generally implements some normally-essential code (I think it's mostly support for error correction and data compression) in the driver software instead of on the modem itself. If you don't have the proper driver for the operating system you're running, the modem will sometimes operate in a suboptimal manner, particularly if you're trying to use it on a relatively noisy line. You'll normally see dropped data, which normally manifests itself as CRC errors on Zmodem transfers (or similar packet errors on a PPP connection) and slightly slower file transfer rates.

"Get a real modem" is generally relatively sound advice for RPI modem users if they have problems when using the RPI modem without its drivers and still want to use an operating system not supported by the modem's manufacturers.

Yes, it's possible to get it to work if you have relatively clean phone lines, and I've seen that done. But there are also people who are not in that situation, and in those cases you're essentially out of luck as long as you decide to continue to use that hardware. Without the EC software, connections at 9600 bps and faster can be a real problem on a noisy line. You ain't using 2400 bps where EC wasn't as important.

FWIW, most RPI modems have had a bad reputation for years (I remember threads on FidoNet slamming them about them YEARS ago because of the high numbers of problems being reported on the net at that time). And AFAICT, it's largely a well-deserved bad reputation. The cost savings just isn't worth it if you want to use something other than Windows...

My two cents.