Test Circuit used for ACID reverse engineering

ACID Reverse Engineering

Schematic

Desoldered ACID chip from Fano's cartridge (thanks, Fano), attached to PC's parallel printer port:

 ACID        PC
 CLK    ---- Strobe
 CCLR   ---- Init
 SIN    ---- Busy
 /OE    ---- Select
 A0..A7 ---- Data 0..7
 GND,5V ---- GND,5V

Source Code

For curiosity, here's the original source code used for reverse-engineering. It's barely commented or user-friendly.

• Media:AcidTest.asm

Pictures

• Original messy circuit
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  Bottom
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  Parents desk

This is original circuit, assembled while I was visiting my parents. I couldn't find a 36pin centronics socket, only a (very) old 25pin RS232 cable, so I needed to use that.

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• Newer clean circuit
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  Nocash Headquarters, don't try this at home

When I came back home, I wrecked the original circuit, and made a miniaturized adapter with robust centronics socket. Not that I'd still really needed it - I've been already done with the rev engineering at that time - I just don't like messy cables.