This is the repository of the HB63C09M Home brew computer.
This is a 10x10 fully functioning HD63C09 Single board computer in the form factor (mostly) of the Z80-MBC2.
This project uses off the shelf IC's and parts with the only legacy part being the HD63C09.
Gerbers are now released! please see the Design files folder, This is what is being called the "PRE-RELEASE" edition. It is ready though really geared towards software folks who might be interested in porting different platforms to the PCB.
A few provisos:
Currently, the board boots to MON09, with the ability to jump to basic. the framework for LBA volume access is roughed into the firmware, and mirrors the LBA access on the Z80 MBC2. The only difference here is the use of Big Endian addressing where 16 bit numbers are sent to the controller.
what is currently needed is help developing ports to flex, Nitros09, Cubix and more. If you think that's you, but the prospect of soldering the board from scratch is a hold up, I have a few pre-production boards left I can assemble and you can keep if you'll help with porting a platform to the computer.
you can find a significantly updated Programmers reference in the documents folder, if interested.
4.2 Is the most recent version of the PCB and is verified to work.
NOTICE: the AHC logic bom has been found to cause issues I have rolled back to the mouser HC bom. Please use this moving forward. issues were found specifically relating to propigation delay of the chipset, in combination with the 74AHC254, which would occasionally cause the ram to miss writes -- especially when the 63C09 was runing in native mode, or when atempting to write the ram from the microcontroller. switching to the HC chips resolves this issue.
You can find more details at: https://hackaday.io/project/193108-hb63c09m-mini-itx-63c09-form-factor-computer -and- https://www.hackster.io/z80dad/hb63c09m-mini-itx-hd63c09-avr-based-homebrew-computer-34904b
Additionally this project is sponsored by PCBWay.com
PCBWay handles all the prototyping costs for the HB63C09M Please check out their website for PCB Fabrication, CNC Mechineing and 3D Printing.
Thank you PCBWay!
PCB and hardware under the CERN-OHL-P V2 Licence
Software is under the GPL 3.0 Licence, Libraries and additional attribution can be found in the "attribution" folder under a specific folder, where they can not also be called out inline.
This Repository uses the floppy emulation code from the Z80-MBC2 Project by Fabio Defabis this code is slightly modified to fit the differing architecutre, however the original code is (C) Fabio Defabis under the terms of the GPL.
You can find details about the Z80-MBC2 here: https://github.com/SuperFabius/Z80-MBC2 -or- https://hackaday.io/project/159973-z80-mbc2-a-4-ics-homebrew-z80-computer
(C) 2024 David Collins