PCI, HSP modems and Winmodems
USR and Lucent have made Winmodems for some time, and they seem to perform acceptably. PCI modems are new to the fold as I write (November 98), and nobody seems to know much about them. They are almost universally HSP (host signal processor) modems, also known as software modems. They use the computer's CPU to do the work, and software to link up. This gives them the advantage of easy upgradeability, just change the software. Two main disadvantages are that they do load the processor, so a fast processor is needed to cope, and of course if you wish to use a non-Windows operating system you need different software. Apart from some NT drivers, little exists! For more info about them look at this page. Another good resource is the PCtel white paper (this is in Adobe Acrobat format). My experience of them so far is limited, but the one I have is performing well up to now! I've left the softmodem bashers and will now defend the good ones.
March update: still little expertise around with these modems. The latest software seems to perform well with most modems, although the Motorola/Shark Multimedia SM56 and the SoftK56 chipsets can be troublesome. Avoid them!
Most chipsets now use auto-sensing software for V90/flex, which can be a problem with some modem racks. Forcing V90 with an init string can solve this.
For the Rockwell hardware modem, that's +ms=12. For the Rockwell SoftK56, it's +ms=v90. The PCtel chipset is a little obscure in this respect, but s38=1n0s37=14 does it (that is a zero in the middle). With this I find the E-tech PCI56PVP to be excellent. The PCtel chipset isn't too fond of connecting to Cisco modem racks though.
December update: Software is improving a lot for these modems. Most HSP modems now represent good value with adequate performance.
A new breed is making its debut too - the Micromodem, aka AudioModem Riser. These are built into motherboards such as those from PCChips (slow site!). These use the PCtel chipset, and, though I have only got my hands on one so far, I can report first-time connections, good speed (46k plus), and even connect to Cisco racks! I didn't get a line drop during the hour or so I was connected with it.
I'm trying to compile more information about them. If you have one, I would appreciate it if you could send me info about it.