Baffa-2 Homebrew Microcomputer

Description

I started this project thinking about creating a machine with a Z80 CPU based on Grant Searle's project but I found so many possibilities that I keep expanding its hardware. I've been studying several old computers that used the Z80 CPU and I'm trying to adapt many of them to this project.

My goal is purely educational and for that, I created an emulator to run the original files (ROM and CP/M) before building my first prototype.

Basic Features:
* CPU: Z80 running at 7.3728 MHz
* Interface: Two high-speed serial ports capable of 115200 Bauds. (one running via wifi).
* Disk: 64MB or 128MB Compact Flash card support, containing 8 or 16 logical drives, respectively.
* RAM: 64K Byte
* ROM: 16K Byte, switched off when CP/M active.
* Resets: Both cold (full reset) and warm reset (used to return to CP/M prompt) circuitry
* CP/M support: 2.2 with included software.

Details

Default Setup:

RomWBW Setup:

Colecovision Setup:d

Terminal Demonstration:

With AY3-8910 Soundboard:

With SN76489 Soundboard:

Components

1 × Backplane The Backplane was originally designed for Baffa-1 Project but intended to be used in many other projects.

1 × Z80 CPU Board

1 × Z80 SIO2 Dual Serial Board

1 × Dual Clock Board

1 × 64KB Ram Board

Project Logs

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Apple-1 Running on Baffa-2
Augusto Baffa • 3 days ago • 0 comments

I've just tested a new set of boards for using the 6502 CPU. The project is slightly inspired by the RC6502 and I believe it may collaborate with it in the future. Initially it is a simple 6502 computer that is capable of running the Apple-1 rom but it should evolve soon.
Baffa-6502 plays Atari 2600 games
Augusto Baffa • 4 days ago • 0 comments

Baffa-6502 is a subproject of Baffa-2 to create a new series of boards around the 6502 CPU architecture. This allows a new group of retro computers to explore in my project.
The first "setup" is an Apple -1 that runs Atari 2600 games (like CP/M that runs Colecovision) and is still in development. For now, I was able to test the new Atari 2600 card for the Baffa-6502 (Codename "Baffatari" 2600)
More info: http://baffa-6502.baffasoft.com.br and https://baffatari.baffasoft.com.br/
Baffa-X Boards - MSX1 Compatible Computer
Augusto Baffa • 4 days ago • 0 comments

Baffa-X is a project to turn Baffa-2 into a MSX1 Computer. It's based on Brazilian Sharp's HB-8000 (Hotbit) schematics and Beer 202 IDE Board. The projects also uses original Z80 CPU, 64KB RAM and TMS9918 Boards from Baffa-2 and will be available soon.

More info at Baffa-X (MSX) Project
Baffavision: Playing Colecovision games on Baffa-2 Homebrew Computer
Augusto Baffa • 04/16/2022 at 23:39 • 0 comments
Baffa-2 Homebrew Microcomputer - Nyan Cat Demo
Augusto Baffa • 04/16/2022 at 22:25 • 0 comments
Baffa-2 Printer Interface
Augusto Baffa • 04/16/2022 at 17:24 • 0 comments

This is a Printer Interface for Baffa-2 :) The next step is to update the BIOS Rom for the Baffa-2 computer to support the printer via CP/M. The BIOS is sourced from Grant Searle and adapted for Baffa-2.
Playing Colecovision games
Augusto Baffa • 04/10/2022 at 03:13 • 0 comments

Coleco ports conflict with 64Kb paged RAM so It's necessary to use a 512kb/Rom board with Romwbw HBios. But I'm having some problems with my 512kb/rom board and It creates some glitches. It means that I'm almost there but I need to fix this to get a fully functional homebrew videogame.
TMS9918 Board
Gameboard
New SN76489 Soundboard for Baffa-2
Augusto Baffa • 04/03/2022 at 23:54 • 0 comments

This is the new dual SN76489 soundcard for Baffa-2 based on the original design by J. B. Langston's SN76489. The board was sponsored by PCBWAY and adds some changes I had to do to get the prototype working properly. This changes are in the back of the board and maybe will be available in revision 1 (how knows... someday).
New Boards Arrived
Augusto Baffa • 04/01/2022 at 00:28 • 0 comments

I've just received four new boards that I designed for the Baffa-2 project. They were delivered by PCBWay and I'm very impressed with the quality of the material of the pcb ( and copper and routes). It was very easy to send the gerber files, view my project preview and place the order using the website. Also, the order was processed and delivered very very quickly. The pads/holes are very accurate and even the small print is clear and well read. I've ordered boards from several other companies and the difference between the boards is clearly visible when looking side by side. PCBWay is really a good choice for your pcb projects and I will be ordering from them other boards that I already have designed for sure.... really very good stuff :)

Three boards are based on the Coleco project by J. B. Langston: TMS9918 Video (same as MSX/Sega), SN76489 Sound and GameControl (the board design is a little different but the authorship and schematics are based on Langston's project and referenced on the boards).

The fourth board is a Parallel PIO based on Stephen Cousin's SC103 and will be used as a printer port for centronics cable (and an epson printer of course) :D

Soon tests and demos ...
Main Kit
Augusto Baffa • 03/02/2022 at 17:24 • 0 comments

Basic PCB Set

The backplane says "Baffa-1" because it was initially designed for the "Baffa-1 Project". Currently, I changed the name to "Baffa-backplane" as it is a general-purpose backplane.

Z80 CPU

Z80 SIO2 Dual Serial Board

Dual Clock Board

64KB Ram

Paged Rom Board

CF Card Board

AY3-8910 Sound Board

Minimal-Terminal version 1