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From: rcollins@altos86.Altos.COM (Robert Collins)
Newsgroups: comp.os.msdos.programmer
Subject: Re: changing cpu speed through software
Keywords: cpu speed
Message-ID: <4363@altos86.Altos.COM>
Date: 8 Nov 90 16:10:42 GMT
References: <1990Nov3.014940.9232@rice.edu> <9802@helios.TAMU.EDU>
Reply-To: rcollins@altos86.UUCP (Robert Collins)
Organization: Altos Computer Systems, San Jose, CA
Lines: 22

In article <9802@helios.TAMU.EDU> briggs@tamunix (Mark Lowe) writes:
>I messed around with the system enough to figure out that an unused bit in
>I/O port 60 or 61 controlled the speed.  Make sure you disable interrupts
>before toggling the bit, though, or you'll hang the machine.
>
>I hope this vague description gives you some clues.
>
By no means is CPU speed change consistent among machines.  Some use
an I/O port.  Some use the keyboard controller, some use memory
mapped I/O.  And you can almost guarantee, that writing to I/O port
61 in this guy's machine won't do it (unless it is the same motherboard
as the abovementioned).

The bottom line?  CPU Speed change is hardware/motherboard dependant.



-- 
"Worship the Lord your God, and serve him only."  Mat. 4:10
Robert Collins                 UUCP:  ...!sun!altos86!rcollins
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