> Ok.  If I have had an internal modem with a 8250 UART
 > chip would it do
 > any good to replace it with one of the others?  Such
 > as a 16550?  Or are
 > you better just going out and buying a more modern
 > modem?
If it has a real 8250 UART chip, and *not* an emulation buried in a much 
larger multifunction chip, then replacing it with a 16550 will provide the 
ability to handle strings of characters with a single interrupt.  However, if 
the internal modem *has* an 8250, it probably can't operate at a data rate 
that would make any real use of the performance improvements that are built 
into a 16550.  So I would recommend buying a new modem instead.
Stay away from WinModems (they work only for Windows 3.x and Windows 95 and 
only for Windows programs in those environments - DOS programs will be unable 
to use the modem.)  If you ever, within the lifetime of the modem, switch to 
another operating system than the ones mentioned above, you will find that 
the modem is invisible to those operating systems and I constantly hear 
people, in this echo and others, as well as on Usenet on the Internet, asking 
for drivers for these modems for other operating systems and being told that 
there are none, there will be none, and they should return their modems to 
the store (if at all possible) or just chuck the modem and buy a *real* modem 
instead and consider this an expensive learning experience.
RPI Modems, those modems with V.42bis in software drivers, are not *quite* as 
bad as WinModems, but I would avoid them if at all possible.  The ten to 
twenty dollars you save on these modems are a false economy (in *my* 
opinion.)  They tie up your computer when the modem is connected to another 
modem and while the modems can be seen in operating systems other than 
Windows (unlike the WinModems mentioned above,) the software drivers to make 
full use of them are also limited to the above operating systems and some 
specially written DOS-based communications programs (most of which have 
nothing else in the way of features  to distinguish them from the market 
leaders such as ProComm.)
Choosing between an internal and an external is personal preference.  I 
prefer the flashing lights that an external has, which tells me what the 
modem is doing (I know enough about modems to be able to recognize when 
something is wrong just by looking at the status lights.) I also like the 
ability to power on and off the modem without powering off the computer as 
well. Plus, I can transfer my modem between my PC clones without opening up 
the boxes, and even shift the modem to my Amigas, for which, no internal 
modems were ever made (to the best of my knowledge.)  But other people have a 
space problem or don't like having a jungle of wires coming out of the back 
of their computers and may only have one computer in the house or for 
security reasons, want the modem not to *develop feet and walk off.* For 
them, internals are better, and they are cheaper since they do not need their 
own power supply or case.
Larry
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