mirror of
https://codeberg.org/cryu/micro-sci-a2-controller
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apple2-bus.pretty | ||
doc | ||
firmware | ||
production | ||
.gitignore | ||
apple2.kicad_sym | ||
eprom.kicad_sym | ||
fp-lib-table | ||
LICENSE | ||
MicroSci Floppy Controller.kicad_pcb | ||
MicroSci Floppy Controller.kicad_pro | ||
MicroSci Floppy Controller.kicad_sch | ||
README.md | ||
sym-lib-table | ||
TTL.kicad_sym | ||
usci.png |
micro-sci-a2-controller
This is a clone of the Micro-SCI / Franklin floppy drive controller.
v0.1 is a direct clone, reverse-engineered from a Micro-SCI board. It was cross-checked with a Franklin-branded board, as well as the (belatedly discovered) official Franklin schematic (included in doc/service_and_schematics.pdf)
v0.2 has the following enhancements over the original design:
- the 2708 EPROM has been replaced with a more-common 2716/2732 EPROM
- decoupling capacitors have been added
- footprints for all capacitors and resistors have been modernized
- firmware EPROM bank selection jumpers replaced with a DIP switch
- obsolete MPS-U51 transistor replaced with modern equivalent
- clearly-marked calibration test points have been added
- ground pours used to increase operational stability
Firmware images can be built via the Makefile in the firmware subdirectory. The build framework requires cc65.
EPROM bank select switches (J4)
- 1:off 2:off - controller test firmware (0x0000)
- 1:off 2: on - 16-sector firmware (0x0100)
- 1: on 2:off - 13-sector firmware (0x0200)
- 1: on 2: on - firmware "put jumpers here" splash screen (0x0300)