This is my attempt at creating a schematic diagram from the PCB of the Souseiki Fammy (創世機ファミー), using KiCad 8.
As I don't have the hardware myself, this is primarily based on some photos taken by Zorchenhimer (following the traces visually), and some work he did with a continuity tester to map out traces that are difficult to see (e.g. hidden behind chips).
The main part of this repository is, of course, the KiCad schematic itself. It is part of the KiCad project, which also contains some other files, some of which are used, others not.
Second, there's a PDF file which contains a plot of the schematic, to allow easier access without having to install/start KiCad.
Additional files:
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analysis.txt holds my higher-level analysis of the circuit. Things like, what the DIP switches do, or the register bits.
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signal-logic.txt holds more details on individual signals in the schematic, including the algebra etc. to figure out what they are.
It also holds some of the conventions used when talking about signals.
While it can also be used for some other things, the primary use case of the Fammy is to copy ROM cartridges to Famicom Disk System disks, and then be able to play those disks later without the cartridge.
The Fammy is designed to sit on top of the Famicom, plugged into it just like a cartridge (albeit much larger), with both the FDS and a ROM cart plugged into the Fammy (which has two slots of its own to allow this).
A switch on the front selects booting from the FDS or from the ROM cart, allowing use of uncopied ROM carts without removing the Fammy.
The front also has a reset button, 4 DIP switches, and an LED.
On the rear, it has a 40-pin (2x20) expansion connector - I don't know if it was ever used for anything commercially.
On the inside, there's a single 2-layer PCB that holds all the electronics, which is what this project is trying to capture.
There are no custom chips on the board, it's all 74-series logic except for the SRAM chip, a standalone BJT, and various passives.