Re: [MiNT] Qfunk bug found? (fwd)

[Michael Schwingen <rincewind@discworld.dascon.de>]

On Sun, May 16, 1999 at 06:58:55PM +0000, kellis wrote:

> I was playing around with MiNTsetter CPU caches.
> 
> Then I noticed that my screen was all messed up If the cache:
> "Data Write Allocate" was off.
> 
> The color of some window content were reversed, the font changed, not
> redrawn correctly etc.
> Very bad, but still the computer was up.
> Then I switch the cache back on, And everythng is back to normal.

This sounds like it it turning off the copyback cache without flushing it
first, which means that from then on, the CPU is working with wrong data
(the one from RAM, where the cache contents were not written back).

If you turn the cache back on, you get the old values (and loose data that
was written to RAM locations that were in cache while it was disabled).

Who does the cache switching? Mintsetter? the kernel?

> (I have a falcon wth ct2 with nvdi 5.0 an latest mint official)

Hm - that's a 030, right? That does not have a copyback cache. Where's my
030 manual gone?

cu
Michael
-- 
Michael Schwingen, Ahornstrasse 36, 52074 Aachen