ldg@necssd.NEC.COM (Doug Gibbons) (09/02/87)
We recently upgraded our VAX 780 from Ultrix 1.2 to 2.0 and experienced modem problems because of it. We have been using a Hayes 1200 SmartModem (EF) to handle both incoming and outgoing calls. After 2.0, we could still make outgoing calls with no problem, but incoming calls would seldom be answered. When they were answered, they were sometimes dropped after a couple of seconds. Upon closer examination of the modem during a quiescent period, we found that with just a getty running on the line, DTR was being raised for 30 seconds once every 60 seconds. Because of this, the modem was in an auto-answer state only 1/3 of the time. If a call came in during the 30 second period, it would be answered, otherwise only RI would flash. Strapping DTR to high via a dip switch was not a desirable alternative. After explaining the problem to DEC support, they suggested rebuilding the kernel and including the *UNDOCUMENTED* option NODSR. I can only guess its function by looking at the header files on our object-only system, but after I put it in, things seemed back to normal. Now, with a getty running on the Hayes port, DTR is always high and all incoming calls get answered. -- Doug Gibbons @ NEC America, Inc. ihnp4!mirror!necntc!necssd!gibbons (214) 580-9334