Server Fault is a question and answer site for system and network administrators. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

Thanks to the fact that our banking industry in Australia is... outdated (which is the politest word I could think of when describing the banking industry)... to do a certain kind of transaction our bank requires us to use a dialup modem and send serial data to them.

When reading through their documentation (last update: 1995), they state that any "Soft Modems" (by which I assume they mean internal modems, as they refer to a AMR socket on a motherboard, which I haven't seen in donkeys years) should not be used because of "possible incompatibilities"

Seeing as buying an external, serial-port modem is actually quite expensive these days and I have a whole box of PCI modems taken out of a bunch of Dells I really don't want to have to buy an external modem. Additionally I think their documentation is simply outdated.

Has anyone had experience with internal modems causing issues, where an external modem didn't?


Thanks for the tips everyone. It would appear that my interpretation of what constitutes a 'Soft Modem' was incorrect. It's interesting to see how these concepts evolve over time! 15 year old documentation never helps the cause either!

share|improve this question
up vote 5 down vote accepted

The actual problem with softmodems (aka winmodems in the era in whch that book was written) wasn't that they were internal. There were/are internal modems that aren't soft modems. Soft modems had less complex physical hardware and used software to emulate many of the features that traditionally were handled by hardware. How different modem manufacturers emulated the features in software varied wildly. Also there were huge problems with buggy drivers.

I don't think you should have any trouble with it now. I use an internal modem to for some of my organizations banking transactions. Granted I am in the US...but banks change slow everywhere it seems.

share|improve this answer
Yep... the reason external modems were recommended was because the abstraction of a serial cable guaranteed that all the processing was being done on the modem itself, rather than offloaded to the host CPU. Then USB modems came along and blurred the line - they can be external modems which are also soft modems. Good quality internal modems will be fine for your purposes - you just need to confirm they run complete processing chips and don't offload to the CPU. – Chris Thorpe Mar 15 '10 at 21:24

Wow... you're taking me way back. I used to work front line support at an ISP back when softmodems hit the shelves.

Soft modems were sometimes a problem because they didn't do any of the DSP stuff on the modem itself, but within the OS driver. This was cool because you could add new features to the modem with a driver upgrade. It was also the source of many problems because you were relying on Windows to do the job previously left to dedicated hardware.

More info at Wikipedia:

share|improve this answer

Back when we used them commonly the main advantage to an external modem for us was that if it locked up on us (which both types did from time to time) we could simply power off the modem without having to reboot the computer -- the internal ones would often take the whole shebang down when things froze up. And oh, how they did freeze up. We had the best luck with U.S. Robotics -- the Couriers were indestructible and the Sportsters only slightly less so. To this day, if I needed a modem I'd probably look for a Courier on eBay.

share|improve this answer

Soft modems were troublesome at the best of times, as the software emulation of proper modem hardware was considerably less than perfect. The PCI modems you have are not soft modems and will work fine. They are build using the same chipsets as external modems and don't rely on emulation software.

If you ever do find a need to obtain an external modem just talk to other admins in your area, as most of us have accumulated a bunch over the years.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.