Newsgroups: comp.arch
Path: utzoo!henry
From: henry@utzoo.uucp (Henry Spencer)
Subject: Re: Differing clock rates in one system...
Message-ID: <1989Dec15.170014.21470@utzoo.uucp>
Organization: U of Toronto Zoology
References: <3069@cello.UUCP> <8861@cbmvax.UUCP> <24992@cup.portal.com>
Date: Fri, 15 Dec 89 17:00:14 GMT

In article <24992@cup.portal.com> Ordania-DM@cup.portal.com (Charles K Hughes) writes:
>      The computer is a 6502 running at 1.79MHz with a 6520, 64k ram/rom, 
>and 3 special purpose chips that provide interrupts, i/o, and graphics.  
>I want to speed up the 6502, 6520, and ram/rom to run at 3.59MHz, and I want
>the other chips to stay at 1.79MHz.  I can get 4MHz versions of the 6502 and
>6520, but not of the special chips.  One of the special chips will steal
>cycles from the 6502 in order to read ram (never writes).  Can I do this 
>without redesigning the computer?

Actually, sci.electronics would have been a better place to ask...

However, the answer is virtually certain to be "no".  All those special
chips will almost certainly malfunction if you try to run them at twice
their rated speed, and it is most unlikely that your machine has any
provision to run different parts at different speeds.
-- 
1755 EST, Dec 14, 1972:  human |     Henry Spencer at U of Toronto Zoology
exploration of space terminates| uunet!attcan!utzoo!henry henry@zoo.toronto.edu
