This project aims at implementing a Sega Master System on a Papilio, that output PAL. The rom images will be read from a SD card with a custom bootloader.
A first working version is out: see this forum post You'll need a VGA wing on AH, a joystick wing (with a 2 button joystick) on AL and an audio wing on BH. You may want a uSD wing on BL.
Regular info on http://fpga-hacks.blogspot.com
Code on https://github.com/ben0109/Papilio-Master-System
Technical info on the SMS can be found at http://www.smspower.org/Development/Documents.
We need to implement the parts of the SMS:
- the Z80 cpu
- the Video display processor?
- the programmable sound generator
- the joypad interface?
- the glue logic
- the memories
To get it to work, we need some io:
- for the video: PAL or NTSC, digitally generated and converted through a R-2R 6-bit DAC
- for the sound: 1 bit, using delta-sigma modulation,
- for snes controllers ?: 2 bits for latch/clock and 1 bit for each controller make a total of 4
- pause button, reset button: 1 bit each
- for the external ram?, to hold the rom image: a 16 bits wing
- for the micro sd card interface: an 8bit wing