SD adapter/reader for the APF M1000/MP1000.
Useage:
The adapter fits in the cartridge slot like a regular APF game cartridge.
The SD is read on boot-up, so needs to be in the slot before applying power.
Reboot (button) will reboot the currently loaded ROM image.
To read a new SD card, power off the M1000/MP1000 and power it back on.
Revision 1 of the reader is set up to emulate all cartridges, including the Space Destroyers which contains extra RAM.
Revision 1B reprograms the PLD to mask the first 4K of the cartridge space as read-only, this affects the UFO catridge.
Revision 1 can load the BASIC 8k section but will have no RAM left to load the program.
The hardware allows for a larger RAM to be used, but development was stopped at the "play all the game cartridges" milestone.
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All chips are DIP, this allowed for prototyping on a solderless breadboard.
There are 3 programmable chips.
ATF20V8B-15PU -- SPLD, 0.3-inch, PDIP-24: This was originally a 22v10 and the "spare lines" were mapped to breakout points for experimentation/expansion on the PCB.
AT28C64B-15PU --EEPROM -- 0.6-inch, 28-pin DIP: Using the PLD, we can remap banks of the ROM, worked with the PCB artist to allow for 27c256 and 27c512...
Atmel: This was an UNO (ATmega328P) and was connected to with a bluetooth serial, it was later programmed with a raw boot image that only read SD and transferred the data to the RAM. Two bank-switch commands were added : Bank-0 will PLD write-protect the cartridge space and remap the boot ROM and RAM on the memory-map. The routine from the boot-rom then calls the boot-vector in order to boot to the cartridge image that was loaded and write-protected (treat it as ROM).
The EEPROM is re-programmable. A routine was created to load the RAM with an updated image of the boot-rom, then the routine re-programs the EEPROM and rebooots. - It is possible to "brick" the device, but it makes upgrades to the boot-rom easier.
--end of edit, Jan-07-2023.--
Initial-Upload of files.
URL Link to My Google-Sites Page : https://sites.google.com/site/apf2sd/home
URL Link to This Page : https://github.com/tom63005/APF2SD/
Note that when I uploaded the files, the comment says 2022 when it should say 2023.
--end of edit, Jan-11-2023.--
Link to UNO Rev-3 board https://store-usa.arduino.cc/products/arduino-uno-rev3?selectedStore=us
(used in the prototype, the finished product uses the ATmega, programmed with a GHEO programmer)
License used earlier was GPLv2, with the provision that anyone can use the code for personal use: learning, experimenting, etc.
I do not beleive there is a profitable application for my code or the circuitry of the experimenter tool created.
I am one person and have no intention of supporting changes to the revision-1 on a corporate development level.
--end of edit, Jan-12-2023.--
Jan-16-2023 :: I located the original PC-Boards (about 30 PCBs in this stack)
... If you are interested in a board, send me a PM ...
I paind to have these manufactured and paid an artist to create the EagleCAD Gerbers.
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Jan-19-2023 :: I found a snapshot of the source-code archived in 2013, before and after the cards were sent to Lance and Adam for "candidate for release" evaluation. - The cards worked for all catridges but needed a re-work of the PLD to block UFO from overwriting the stack on the 2nd time it was played. I uploaded the "re-work" with the original git-hub create. The Arduino code is from the snapshot taken: Dec-2013.
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