jcm@mtunb.ATT.COM (was-John McMillan) (01/03/89)
In article <453@uncle.UUCP> jbm@uncle.UUCP (John B. Milton) writes: >In article <295@arnold.UUCP> dave@arnold.UUCP (Dave Arnold) writes: >>In article <779@rush.cts.com>, bob@rush.cts.com (Bob Ames) writes: >>> We've got uugetty on the AT&T (3.51, hardware flow control enabled, >>> new combo PROM, HDB/BNU). >> ^^^^ What is a new combo PROM? My Combo card causes my system >>to hang when I use tty001 or tty002, do I need a hardware patch? > >This is NOT a rom upgrade, it is a replacement Zilog 8530 serial chip. >It seems that Combo Boards Rev F. were made with a bad batch of chips. If it was correctly explained to me a year ago: Combo Boards of Revision Level "F" and newer were made with an altered oscillator logic that, belatedly, disclosed a Zilog serial chip defect. The defect occurs as an occasional sustained "ringing" of the Special-Receive-Interrupt which can tie-up the system for seconds at a time, or can crash it (through Kernel-Stack exhaustion?). No software work-arounds could cope with the ringing. It is recommended that the chip be replaced (via the HOTLINE?) if owner's of Rev F. and newer combo-board's are experiencing multi-second system lock-ups or crashes while doing UUCP's or upon receiving BREAK's on Combo-Ports. JCM -- att!mtunb!jcm ... speaking only for himself, if that.