Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!watmath!clyde!cbatt!cwruecmp!neoucom!wtm From: wtm@neoucom.UUCP Newsgroups: comp.sys.att Subject: Re: 6300 Clock & PC-DOS 3.1 Message-ID: <381@neoucom.UUCP> Date: Mon, 9-Feb-87 17:22:12 EST Article-I.D.: neoucom.381 Posted: Mon Feb 9 17:22:12 1987 Date-Received: Tue, 10-Feb-87 18:36:44 EST References: <254@rocksanne.UUCP> <967@ur-tut.UUCP> <1969@mmintl.UUCP> Organization: Northeastern Ohio Universities College of Medicine Lines: 48 Summary: possible sources of clock problems A: I run AT&T DOS 3.1 without an ethenet card and also without enet.sys. I have experienced little trouble with the system clock. Congrats to AT&T for not having the date rollover bug that so many other implementations of DOS have. On many flavors of MS-DOS and (all flavors??) of PC-DOS, if the first BIOS call after midnight is a disk operation, the flag that indicated date rollover is lost, and the date is a day behind at the occurance of the next timer tick. Either I have been lucky or this is not a problem on AT&T MS-DOS. B: Possible clock problems. 1. Sappy batteries cause the clock to loose time. This happens when the battery itself poops out, or if the machine is used infrequently. 2. It has been my experience that about 3/4 of the 6300s that we have have a tendency to loose time at about 1 min/day. You could try to adjust the trimmer cap. next to the clock chip. With a low-capacitacne scope lead, a frequency counter should read 32 768 . 000 Hz. 3. Resident Diagnostics version 1.43 cures some problems related to getting goofy times, if the time rolls over while the clock chip is being read. 4. Some overly IBM-specific programs are confused by the 6300's way of keeping the system time-- Norton Utilities, for instance. 5. This shouldn't matter, but could leaving the ethernet board in your computer but taking enet.sys out of your config.sys file leave the hardware on the ethernet controller in a state that keeps the clock from working correctly? That is, IF you left the board in. C: One of our 6300s is weird. It stops keeping time when the a.c. power is off; almost as if the clock oscillator is not running. The time when the system was shut off is frozen while the a.c. is turned off. I haven`t had time to put my oscilloscope to it yet to see what is going on. --Bill Bill Mayhew Division of Basic Medical Sciences Northeastern Ohio Universities' College of Medicine Rootstown, OH 44272 USA phone: 216-325-2511 (wtm@neoucom.UUCP ...!cbatt!neoucom!wtm)