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Memory Schematic
03/02/2019 at 04:05 • 0 commentsSchematic diagram of the arcade game memory. Program memory is provided by a 27C512 EPROM, and RAM by a pair of CY7C162 static RAM chips (chosen because they have separate input/output lines, which makes implementing the "upstream tap" for the cheap video circuit easy).
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Minor Catastrophe
02/27/2019 at 05:09 • 0 comments -
Memory Map
02/19/2019 at 00:18 • 0 commentsHow the 64KB address space is allocated & decoded.
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Designing for MC6809 or MC6809E
02/18/2019 at 20:43 • 0 commentsHere is the schematic of the CPU part of the design, which shows how to design for either a 6809 or 6809E processor. Note that this depends on certain processor-specific functions (TSC, LIC, MRDY/AVMA, DMA/BUSY) not being used. Note that I haven't actually tested this with a 6809E yet, so you're on your own if you decide to copy it...
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Status VLOG
02/07/2019 at 22:57 • 0 commentsSee YouTube Playlist for updates.