Re: 6522 vs 6526 (was Re: 6502 to 8501: new details)

From: Andre Kaesmacher (andre_at_kaesmacher.de)
Date: 2002-02-28 02:22:53

ruud.baltissen@abp.nl schrieb:
> 
> 
> The 6502->8501 design is based on my 6502->6510 design. And the 6510 has a
> data-direction register. (Although I wonder if it is used ever again aftre
> the first initialisation) AFAIK the 8501 has a DDR as well. So the 6529

<nitpicking>
The only way to measure the temperature of the CPU!
</nitpicking>

As published by Richard Atkinson:

set DDR as output
set DR as one
set DDR as input
wait until DR is zero

However, because there are no known programs for the +4 which
use this feature, it might be abandoned.
OTOH, keeping this feature would be cool!

(Completely ignoring the fact that common IO Chips do not
have such a undocumented feature as the 6510/8501)

A.K.

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