Xref: utzoo comp.sys.att:9696 comp.sys.ibm.pc.programmer:1741
Path: utzoo!attcan!uunet!snorkelwacker!usc!rutgers!soleil!gopstein
From: gopstein@soleil.UUCP (Rich Gopstein)
Newsgroups: comp.sys.att,comp.sys.ibm.pc.programmer
Subject: Re: How does DOS time work?
Summary: fast interrupt rate
Message-ID: <980@soleil.UUCP>
Date: 1 Jun 90 12:53:41 GMT
References: <1094.266605B1@onebdos.UUCP>
Organization: Harris Semiconductor, Somerville, NJ
Lines: 28

In article <1094.266605B1@onebdos.UUCP>, Robb.Thomas@f1.n684.z89.onebdos.UUCP (Robb Thomas) writes:

>       You should try booting your machine off floppy under a 'generic' 
> version of MS-DOS.  Next, run your clock utilities off the floppy, and POOF, 
> your clock problems should go away!
> 

I am using generic MSDOS, and am running my clock utility seperately
in autoexec.bat.  The problem is that after the machine boots it has the
correct time, but DOS time runs FASTER than real time.  If I wait a few
minutes, the DOS time is a few seconds ahead of wall-clock-time.

I pulled out the schematics for the 6300 last night, and armed with my
calculator, determined that the 6300's timer tick runs at 18.75 ticks/sec
instead of 18.2 as in a standard PC.  The easiest solution would be to
slow the timer down to 18.2 tick/secs, but the timer is already running
as slow as it can be set...  

The question is:  How can I get generic DOS (4.0 in my case), to keep
the correct time given the 18.75Hz clock rate?

Rich

-- 
Rich Gopstein

gopstein@soleil.nj.semi.harris.com
..!rutgers!soleil!gopstein