🚀 go-pugleaf

Hi, all.  I just realized that I have been using a UART 8250 serial port that
came with the motherboard of my IBM PS/1 with my USRobotics 14.4K V.42bis
fax modem.  I think I have been getting 57.6K throughput without any problems
all along when connecting to various BBSes as well as the IBM Advantis
network using my OS/2 Warp Internet Access Kit.  Lately, I have installed
TCP/IP 2.0 on my OS/2 system and I have been using it to access the LAN
at work.  Everything is OK except that the throughput seems to be low and 
that I get these beeps coming from my PC whenever there's large amounts of
data being transferred through the modem even though I have set up the 
connection to use 57600.  After talking to some people at work, I realized that
the problem is that I do not have UART 16550 which I am told is required to
support 57.6K.  Why I do not seem to have problems when I go to BBSes as
well as directly through IBM Advantis at this speed I not know.  However, 
nonetheless I went out and bought an IO card which has 2 serial ports (one 
with 16550 UART), 1 parallel port, and 1 game port.  I thought it would be a
simple matter getting my modem to exploit the 16550 UART with this.  As it
turns out, for some reason, I can get my system to know that my modem is
connected to this 16550 UART serial port, but my modem cannot be initialized.
While testing this, I booted back to native DOS, and using the tool MSD, I can
see that the 16550 UART is recognized under COM 1 (for testing purposes, I
disabled the two serial ports on my motherboard).  However, the settings for
CTS and DTR are NO instead of YES.  Through experimentation, I found out that
when my modem was connected to a working serial port, these two parameters
appear as YES in MSD.  I think this may be the problem.  As a result, I cannot
issue any AT commands to my modem.

I do not think I have set up anything wrong in terms of IRQs and jumpers.  I
even took the card back to the shop where I could see it working when tested
using a mouse.  Unfortunately, the shop did not have the facilities or the 
patience to bother with testing it with a modem for a CDN$25 item.  Even with
this 16550 serial port configured as the only activated COM port did not work.
I am convinced that there is some incompatability issue here.  I also checked
the dip switch settings on my modem but I do not think they are relevant in
this case.

I am deperately seeking for advice on solving this problem of mine.  Any ideas
on this will be very much welcome.

===============================================================================
Frankie K. Sun (dxer@vnet.ibm.com)

IBM Toronto Laboratory
1150 Eglinton Ave. East
North York, Ontario
CANADA M3C 1H7