The CFT Project

The CFT is a home-designed, home-built mini-computer made from scratch. I've designed and built the instruction set, data path, processor, computer, software stack, cross-assembler, emulator, software toolchain and even some of the tools needed to do this. You can call this a ‘fantasy mini’. I'm in the process of testing the processor and building peripherals and the ROM, while trying to document the whole thing.

Hardware

The CFT Project: Summary

The CFT is a homebrew mini-computer made from scratch out of discrete logic chips. I’m making the instruction set, processor, computer and software stack from scratch in my increasingly sarcastically dubbed Copious Free Time.

2010

hardware

State of the CFT

Sub-project	State
Backplane	Done.
DFP Board	Being tested.
MEM Board	PCBs received.
Front panel	One of four modules done.
Case	Being designed.
DFP Firmware	Porting from DFP1 firmware.
CTL Board	PCB finalised.
REG Board	PCB received.
ALU Board	PCB finalised.
BUS Board	PCB finalised.
Processor	Passing Verilog tests.
Documentation	Out of date.
Verification	Updating test benches.
Cross-Assembler	Done, passing tests.
Emulator	Implementing 2019 features.
Firmware	Waiting for Verification.
Operating System	Waiting for Verification.
Forth	Waiting for Verification.

The CFT Book

The CFT Book is an insane amount of notes collected together, and slowly formatted into proper documentation. It'll probably be a draft forever.

2013

Front Panel Module

June

DFP Board

Last October

Backplane: It Fits!

Parts for the backplane have arrived and everything fits properly.

Last September

MEM Board Render

The MEM board holds 512 kW to 6 MW of RAM and 512 kW of ROM.

Last September

I just realised the new Memory Banking Register unit has a serious bug that's only evident at the microprogram level. This will take a bit of redesigning to fix, but hey: that's what testing is for. It's just a bummer the Programming Model document and the Microcode Emulator will have to go on the back-burner until I fix this.

Last September

DFP 2 Render, revision 1939

I messed up—the previous revision of the DFP had the backplane connectors mirrored, so it'd never have mated. I chose to redo the board from scratch, but the layout is better and it looks nicer now.

Last September

The CFT project is now on Github. You'll find it at github.com/alexiosc/cft.

Last August

The CFT Book, 2019 Edition

The CFT Book is an insane amount of notes collected together, and slowly formatted into proper documentation. It'll probably be a draft forever.

Last August