Chip Yamasaki <chip@osh3.osha.gov> (04/30/91)
I've got a problem with REAL BAD bursts of noise (or something like it) on my system. The situation is this: I have an ITT 386 system running SCO Xenix (286, don't ask why) which I'll refer to as "the 386", and an ALR MultiAccess system running SCO Unix Sys V 3.2.2 which I'll refer to as "the 486". The 386 has 9 T2500 modems on a 16 line rotary with the interface locked in at 9600 baud and they are plugged into ports on ITTs MTS multiport cards. The 486 has 2 T2500s on non-rotary lines at 19,200 plugged into the ALRs multiport option boxes. The two systems have a direct cable at 9600 to log into the 486 from the 386. I am getting bursts of "noise" that are terrible when I dial in from home (25 miles, normally good lines) using a Codex 2400 bps or Telebit T2500 on a PC. The noise happens only occasionally and comes in occasional bursts. It happens more when I am in the 386 system and most when I am in the 486 from the 386. At first I thought it could be the rotary giving problems when another call comes in (and I still think that may be a contributor), but I get it on the 486 sometimes. Does anybody know anything about the T2500 that might contribute to the problem? Does anybody know anything about problems with noise on rotary lines when a call comes in to a neighboring number? Does anybody know anything about problems with SCOs serial port drivers that might make them generate garbage if they are under stress? Any other ideas? Any help would be greatly appreciated. This is driving me nuts! Charles "Chip" Yamasaki chip@oshcomm.osha.gov