Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ukma!husc6!m2c!wpi!jhallen
From: jhallen@wpi.wpi.edu (Joseph H Allen)
Newsgroups: comp.sys.m6809
Subject: Re: fast clock for 6809
Message-ID: <2171@wpi.wpi.edu>
Date: 3 May 89 01:09:24 GMT
References: <1605@ccnysci.UUCP> <1984@wpi.wpi.edu> <410@aucis.UUCP>
Reply-To: jhallen@wpi.wpi.edu (Joseph H Allen)
Organization: Worcester Polytechnic Institute, Worcester, MA. USA
Lines: 23

In article <410@aucis.UUCP> easton@aucis.UUCP (Jeff Easton) writes:

[ -stuff- deleted ]

>  Moral of this story,  The 2 Mhz chip is the same die as the 1 Mhz
>version, its just been tested and guaranteed to work reliably at
>2 Mhz.  You can proably take a 1 Mhz part and run it at 6 Mhz.  You would
>proably need a heatsink on the chip and even then, all the other peripherals
>proably wouldn't keep up with it.
>
>  Notice that I have never tried the above, I only think it would be neat
>to try.  In college someone once boasted that they took a SWTP 6800 machine
>up to 12 Mhz before it quit.  The first part to die was a 6850 ACIA.

Another neat thing to do is try to see how slow the chips will run:  6800 and
6809 have a minimum clock speed because they use DRAMs for the registers.  How
many seconds can you hold up the clock....  (actually there are even some
applications for this: if you want the CPU to be synchronized to a video
system and you do it by stopping the clock during verticle or horz blanking,
or if you only want to processor to run only during the blanking...)

Ps:  6809 and OS9 should have become the standard PC, not the IBM PC (we were
robbed...)