*updating* 8088's

[Allison]

>
>Subject: Re: *updating* 8088's
>   From: Jim Leonard <trixter at oldskool.org>
>   Date: Tue, 20 Nov 2007 19:35:14 -0600
>     To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org>
>
>Chris M wrote:
>> --- Alexis <thrashbarg at kaput.homeunix.org> wrote:
>>  
>>> You might run into an issue of minimum clock speed
>>> too. I don't know what
>>> the minimum for the 386/486 is. I know RISC
>>> microcontrollers can go down to
>>> DC, but the 8386/486 might not.

Correct they are dynamic internally.  The minimum clock is 
far slower than most would tolerate (under 1mhz).


>>  Presumably the boards these things come with have
>> their own crystals. I would not expect a '486 upgrade
>> for a '286 to run at 8mhz or anything comparable (but
>> Tony could tell us).
>
>They did indeed.  Which brings us to why these were stopgaps at best: 
>The processing may have been faster, but the memory/bus interface was 
>the same, so you were not truly getting the overall performance of the 
>real machine (that's why the advertised benchmarks were careful to 
>demonstrate how much faster the upgraded machine was compared to how it 
>was before, and NOT to a "real" 386).

Some resorted to PLL chips top multiply the existing clock to
something fast.

Allison

>-- 
>Jim Leonard (trixter at oldskool.org)            http://www.oldskool.org/
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