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From: dank@eng.umd.edu (Daniel R. Kuespert)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Leading Edge Clock Problem
Summary: There's a device driver
Keywords: Leading Edge Clock
Message-ID: <1990Apr9.021431.5531@eng.umd.edu>
Date: 9 Apr 90 02:14:31 GMT
References: <3822.261de7ec@vax5.cit.cornell.edu>
Sender: news@eng.umd.edu (The News System)
Distribution: comp
Organization: Maryversity of Uniland, College Park
Lines: 48

In article <3822.261de7ec@vax5.cit.cornell.edu> pv9y@vax5.cit.cornell.edu (O) writes:
>
>       Here's an odd question.  An office I do some stuff for has two
>    Leading Edge PCs (Model D).  BOth have real-time clocks.  Recently
>    the hard drive on one died completely and I replaced it.  However,
>    this machine was old enough that I used a DOS 3.3 that came with
>    an Epson Equity II+ instead of the DOS 3.1 that was on the Leading
>    Edge's dead hard disk.  Since that time the clock in the Leading
>    Edge whose hard drive died won't keep the time through a cold
>    boot.  I checked the CONFIG.SYS file on the other Leading Edge and
>    that only has the usual files and buffers lines - so there's no
>    clock driver in the config file.  It seems odd that the clock
>    should stop at exactly the same time as the hard disk, so I'm
>    prone to believe that there is a software answer.
>
In my Model D (which I'm using at this very moment) there's a device
driver that DOS needs to read the realtime clock from the motherboard.
(The name is CLKDRVR.SYS)  This is most likely the problem; I don't
have an explanation for why your other LE-D doesn't have the
DEVICE= line in CONFIG.SYS.  Getting Microsoft to modify MS-DOS to
incorporate special features is an expensive proposition, and it's
unlikely that Leading Edge would have gone this route when they could
do it through a simple device driver.

Go and find the original DOS disks and reinstall them. Using a DOS
from another clone is a risky thing to do unless it's Microsoft's
generic version.

>       Assuming the version of DOS I installed is the reason for the
>    clock to stop working, is there an easy way to install an older
>    version of DOS over a newer one without re-formatting?  Can I just
>    delete the COMMAND.COM and the two invisible files and replace
>    them with the equivalent ones from the older DOS?

Boot from the floppy with the DOS you want to install and use the SYS
command (from that floppy) to overwrite the system files and COMMAND.COM.
You'll have to copy the CLKDRVR.SYS file separately, though, and install
it in CONFIG.SYS yourself.

regards,
dan

Daniel R. Kuespert, Ph.A.
Chemical Process Systems Laboratory
University of Maryland, College Park
College Park, MD 20742

dank@eng.umd.edu