2014
RE: [oberheim] Re: Faster CPU & firmware mod for the Oberheim Matrix 1000
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chriswareham@chriswareham.demon.co.uk
Sep 11, 2014
Hi Jan,
The ANDA instruction will perform a logical and of the contents of register A with the immediate value argument. Register A being the eight most significant bits of register D. In your example, it's performing a logical and on the most significant bit of register A.
Cheers,
Chris
From:
oberheim@yahoogroups.com [oberheim@yahoogroups.com]
Sent:
10 September 2014 20:52
To:
oberheim@yahoogroups.com
Subject:
[oberheim] Re: Faster CPU & firmware mod for the Oberheim Matrix 1000
I'm not really that far into the disassembly yet, but what I find at that point of the code is this:
ANDA #$80 *C693: 84 80 '..'
So, no adding, rather an AND, so the patch value would rather have to be 0x7F - or am I wrong there