eightbit.computer


My 8-bit hardware projects: breadboard + PCB computers, NES recreation, and more!


Breadboard 6502 Computer

Built for CMU 98-341 (which I now kind of TA). Many thanks to Salix, Sky, and Robbie for all the help.

Architecture: 6502 CPU, ROM, RAM, simple I/O. Based off of the Ben Eater 6502 computer, with minor changes.

[ course docs | ben eater ]

Unbreadboard Computer (PCB)

Same high-level architecture as the breadboard build, migrated to a PCB. Includes a CH32X035-based flash programmer: 6502-debugger.

Focus: robustness in wiring, integrated flash programming, smaller form factor.

Next Steps: V2 with keyboard support (over UART) and VGA display support (using a derivative of Sky's VGA Driver). "Breadbox" computer + keyboard case design.

[ schematics | assembly bom | hand-assembly bom ]

NES Recreation

In progress. A from-scratch recreation of core NES subsystems with the goal of eventually running NES games. Emphasis on learning and accurate interfaces over speed. Should pass the Accuracy Coin NES behavior tester.

Currently looking into PPU emulation and understanding differences between the 6502 and the Ricoh 2A03. Generally trying to figure out how everything works.

[ dev log (soon) | coming soon ]

Anycomputer

In ideation. A modular backplane plus swappable modules (CPU, RAM, I/O) to enable a mix-and-match 8-bit computer. The backplane provides bus power/lines; modules identify via DIP-switch address mapping. First targets: 6502 (NES, Apple II, VIC-20) and 6510 (C64) systems .

[ concept overview | backplane pinout (soon) ]

6502 System on a Chip

Waiting until I learn SystemVerilog. An SoC implementation of the 6502, SRAM, GPIO, and more. Aiming to tapeout on TinyTapeout's 130nm process.

Hopefully will use the shorter propogation delay to run at clock speeds in excess of 50MHz (and maybe 100MHz :o), beating the record set out to break by 6502 designer Bill Mensch


About

I’m Matthew. This is my online repository for mainly 6502 based 8-bit hardware projects. Is this esoteric? Totally, but hey, it's fun.

Contact

My Personal Website


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