Re: [cc65] Atari Extended Memory Driver Anybody?

From: Oliver Schmidt <>
Date: 2012-09-10 14:21:20

> [...] which should make the driver simpler and faster.

Talking about optimizations: Judging from this in your 130XE driver
"@4:     jsr     STACK                   ; copy one byte" it seems
that you call to the stack routine for every byte on copyfrom and
copyto. Is there a sepcific reason why you don't do the copy in that
scenario page by page (similar to the map/commit scenario) with the
last page potentially being a partial page? I must admit I haven't
fully understood the source - I more or less just saw your comment...

> At the least it shows MULTDEMO run the way it should... loading different
> drivers and picking one that works.  Speaking of MULTDEMO, does it only
> check a certain number of files in a directory (doesn't seem to, looking at
> the code, so maybe it's readdir that does this?)  I noticed putting the
> driver further down the directory list causes it to not find the driver.

That has to be an issue with readdir() as the MULTIDEMO runs fine on
the Apple II. Interestingly the CBM readdir() seems to have the very
same problem. I've written a small test program to reproduce it on
CBM. Maybe you want to check on the Atari to see if it reproduces the
issue there too:

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Received on Mon Sep 10 14:22:03 2012

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