Cheap PC modems ... use w/ a Mac?

The question on sharing an internet connection started me thinking about my own computers.

Specifically:

I have a PowerMac (beige; pre-USB) that I would like to hook up a 56K modem to. Now, every external modem I’ve every used has been designed for both PC and Mac–you just plug in a different serial cable adapter, and install the appropriate driver.

If I buy a PC 56K modem, will I be able to use some generic modem driver to run it? (Apple serial modem tool? I’ve never had to use it, but I think it ships w/Macs…) I ask b/c I’m cheap, will use this modem only infrequently, and PC modems seem to cost about half what Mac modems do.

Hardware-wise, all you need is an adaptor to adapt the PC modem cable’s DB-25 (I think?) end to a Mac serial DIN-9. Or buy a standard Mac modem cable, either way.

Software-wise, you need to select a “modem description” file for your Modem Control Panel to use with PPP dialup, and if you use proprietary dialing programs that doesn’t rely on the Modem Control Panel (AOL, for example; lots of FAX software for another), you’ll need to pick from the list of known modems there as well. That means that you can do what you want to do if you buy a PC modem that is a direct analog of a Mac modem that appears on these lists. Mainstream modems from well-known companies like Hayes, Zoom, Practical Peripherals, and Supra should work fine. You may also get away with off-brands that are “100% Hayes-compatible” by selecting “Hayes Optima 56K” or “Hayes Accura 56K” from the list, but YMMV.

Don’t buy anything named “Winmodem”.

External modems are all generally compatible with any computer with a serial port, hardware-wise. (I know this first-hand from a long association with Amiga computers which are poorly supported by most hardware manufacturers.) The only Mac-specific requirement is a Mac modem cable. The trick is software. Theoretically, you can figure out the initialization string yourself and get it working fine with your Mac. Most decent external modem makers include an appendix in the manual that details the AT commands the modem supports.

NB All internal PC modems are totally incompatible with pre-PPC Macs. PCI modems may work with PCI Macs if the manufacturer includes a driver.

NB2 IIRC, Winmodem is a 3Com/USR trade name. Check their website to see if they offer any PowerMac drivers for their PCI internal modems.

Don’t Mac modems require carrier detect to be set HIGH? That’s a switch on a PC modem you used to have to change but I don’t know today. ebay.com probably has tons of cheap Mac modems though.