Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!samsung!usc!ucsd!rutgers!mcdchg!ddsw1!andyross
From: andyross@ddsw1.MCS.COM (Andrew Rossmann)
Newsgroups: comp.sys.ibm.pc.hardware
Subject: Tis a puzzlement
Message-ID: <1990Aug10.002428.16237@ddsw1.MCS.COM>
Date: 10 Aug 90 00:24:28 GMT
Reply-To: andyross@ddsw1.MCS.COM (Andrew Rossmann)
Organization: ddsw1.MCS.COM Contributor, Wheeling, IL
Lines: 22


  I have a rather interesting problem. I noticed that when I ran my
INFOPLUS program, that COM1 (which is a Practical Peripherals 2400 baud
internal modem) had a baud rate of 2! I tried changing it to something else
with the MODE command, but it wouldn't budge. I'd been (and still am) using
it with no problems, until I tried running DSZ. It complained that the port
was defective. What is really strange is that this happened when I was
running it 'plain.' I've generally been running under Windows 3, and it
works fine then!! (Under 386 enhanced mode.)
  I tried pulling various cards, but nothing changed. I then put the modem
in my old computer (Tandy 1000SX), and there were no problems. I tried it
in a Tandy 3000NL, and it worked fine there, too (at both 8MHz and 10MHz
bus speeds.)
  My computer is a Gateway 2000 386/25 w/ cache (Micronics) and the bus is
set to 8.33MHz. If I slow the computer down, the baud rate is 'stuck' at
452 baud.
  Has anyone seen something like this before? And why does it work fine
under Windows 3 enhanced mode?
  The UART on the modem card is a surface mounted 8250. 

  Andrew Rossmann
  andyross@ddsw1.MCS.COM