Yes, Bryan - today's modems will work on a Tandy 1000SL. The
   Tandy 1000 SL is an XT-compatible, running at approximately 8
   Mhz. External modems will run to speeds up to 9600 bps reliably,
   so if you want an external modem, getting a 14.4 and running at
   9600 bps would be a safe bet. *[as 14.4's are relatively cheap
   nowadays] Internal modems are a better choice. *I don't have
   experience running internal modems on an XT-compatible (I have a
   286 - 1000 RLX :-> ), but I suspect you can run an internal
   modem (as long as it has the 16550A UART chip on it - look for
   it!!), you should be able to run the modem at the speed its
   rated at. Data compression is a different story - on my 286
   here, even though my modem says "57,600 with compression", I can
   usually safely run the comm port at 38,400, and always safely
   run it at 19,200. *But one important thing to remember: the
   difference in most transmissions is *small* between using modem
   data compression and not using modem data compression.
   Transferring binary files (.ZIP, .GIF, etc) will never run at
   57,600, 38,400, or 19,200 on a 14,400 bps modem. *They will
   transfer between 10,000 bps and 17,000 bps, depending on how
   good your connection is, how fast your hard drive is, and the
   hard drive of the sender is, etc. Hope this helps! *My
   suggestion is: Get an internal modem - 14.4 or 28.8, your
   choice. *I know that the 14.4 will work great (there is at least
   one SL owner on here (Yee Chang Lee) who runs a 14.4 at 19,200
   and is pleased with it. *I don't know for certain how a 28.8
   would work, but I can't see why it wouldn't run at at least
   38,400. Ken