MMU changes wasRe: [Coco] Re: Coco Repack

Willard Goosey goosey at virgo.sdc.org
Tue Aug 10 05:13:52 EDT 2004


>From: KnudsenMJ at aol.com
>Date: Mon, 9 Aug 2004 23:24:34 EDT
>
>In a message dated 8/8/04 1:55:34 PM Eastern Daylight Time, jdaggett at gate.net 
>writes:
>
>> Yes you can establish page size to any size block of memory that you want. 
>1K 

Rather than changing the block size of the GIME's MMU, I'd add more
contexts.  It only has two.  4 would be cool, more even better.

IIRC, to print a character on the screen, an OS-9 program goes through
3 context switchs: user program -> kernel -> grfdrv.  The first
task-switch is nice and quick, the kernel lives in context #0 and the
user process in #1.  But that third switch has to save the user
context somewhere and load grfdrv's.  Then it has to switch back.

>Maybe that would be OK.  But given the number of good apps (and OS-9 as a 
>whole) written with 8K blocks, do we really need to screw with this now?
> --Mike K.

Gotta agree.  Even my idea would probably break lots of software. :-(

Willard
-- 
Willard Goosey  goosey at sdc.org
Socorro, New Mexico, USA
"I've never been to Contempt!  Isn't that somewhere in New Mexico?"
   --- Yacko



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