mengm@homxa.UUCP (P.MENG) (04/19/84)
We recently had problems with the Racal-Vadic auto-dial VA212 modem. When using it with a remote terminal characters that were being transmitted from the host were being dropped intermittently. This can be evidenced by running a small shell program like the following: while : do; echo SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS done After contacting the vendor and our computer center the problem was found to be a compatibility problem with the Micom port selector and the Racal-Vadic. Appararently (not proven yet) the Micom port selector, a facility to accomodate dial-up and dedicated lines to the mainframes, at certain times will transmit characters at speeds greater than 1200 BPS. It was found that the Micom would transmit up to 1235 BPS (any Micom people out there care to refute this?). It seems this was never a problem before because most modems can handle this overspeed condition. Anyway, Racal Vadic was notified and provided somewhat of a fix for the problem. They sent us a replacement rom chip (prototype) to handle speeds up to 1225 BPS which is a lot better but still not 100%. Racal Vadic engineers say this is as fast as they can get it. This new rom chip should be available shortly. Incidentally, this pro- blem only seems to exist on the auto-dial model. Peter Meng