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:

MSX1 Setup:

MSX2+ Setup:

Terminal Demonstration:

With AY3-8910 Soundboard:

With SN76489 Soundboard:

I am proud to say that this project is sponsored by PCBWay.

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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Baffa-2 at RetroRio 2022
Augusto Baffa • 04/04/2023 at 15:10 • 0 comments
Baffa-81: Running ZX81 on Baffa-2 Homebrew Computer
Augusto Baffa • 11/27/2022 at 16:08 • 0 comments

After all, I had to create a set of boards to clone my beloved first Sinclair ZX81 computer. Using the Baffa-2's CPU and Dual Clock board, it is possible to add 3 more boards to provide 32KB Ram/Rom, Keyboard and Cassette and Video I/O to build a ZX81 Clone.

For more information, More info: https://hackaday.io/project/188406-baffa-81-zx81-compatible-computer
In this photo, the Baffa-81 is using the new Baffa-2 backplane lite which has only 6 slots (original has 12 slots). This option was created because it is cheaper and can be used on smaller sets of boards.
Baffa-2 ZX81 Boards on its way!
Augusto Baffa • 09/25/2022 at 07:11 • 1 comment

Baffa-81 is a Sinclar ZX81 clone on Baffa-2 Homebrew Computer. It's based on Grant Searle's ZX80/81 Project and Wilco's ZX80/81 board. Also, the ps/2 interface is based on Danjovic's Tek v2 project.

All boards have arrived! Now I need to have some time to assemble and test them. I would like to thank PCBWay again for all their support on the Baffa-2 project. In addition to the boards being great (excellent quality), manufacturing and delivery are very fast.

Projected boards:

I had also created a reduced version of my backplane to reduce costs of this project :) . It's half the original backplane with only 6 slots. Can be connected to others via expansion port.

To complete the setup, it is necessary to use the Z80 CPU board and the dual clock board.
Baffa-X: MSX1 Compatible Computer tested!
Augusto Baffa • 07/22/2022 at 00:31 • 0 comments

Baffa-X is a project to transform 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 the original Z80 CPU, 64KB RAM and TMS9918 Boards from Baffa-2.

For more information check Baffa-X project page
Apple-1 Running on Baffa-2
Augusto Baffa • 06/28/2022 at 06:05 • 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 • 06/27/2022 at 03:53 • 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 • 06/27/2022 at 03:47 • 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.

View all 14 project logs

Discussions

John wrote 08/04/2022 at 17:41

Can this emulate the ZX81 or ZX Spectrum? That would be very interesting.

Are you sure? yes | no

Augusto Baffa wrote 08/04/2022 at 19:01

Well, it's not an emulation because it uses the same real components but the answer is yes, sure!

ZX81 set was designed last march and were the first boards I designed for Baffa-2 architecture but I prioritized other computers 'cos I assembled a ZX81 before this project. That will probably be the next set of boards I'm going to order and assemble... (check this out https://baffa-2.baffasoft.com.br/whatsnew.php)

ZX Spectrum I haven't been studying yet but is possible after have my ZX81 running. Even commodore 64 later since I've been working with 6502 CPU as well. For now, I'm studying the schematics from Apple ][+ computer and would be nice if I could design boards for it. In Brazil (where I live) the most common computers in 80s were Apple][+(and IIe), ZX81/ZX Spectrum and MSX (the most popular).

Are you sure? yes | no

John wrote 08/06/2022 at 10:06

Great! Looking forward to see your boards for the ZX81 (that was my first computer). I still remember how amazed I was when I found out the ROM programmer was using a single IC, the Z80A, for both the ZXBASIC and for composing the video output signal. Keep up the good work.

Are you sure? yes | no

Baffa-2 Homebrew Microcomputer

Description

Details

Default Setup:

RomWBW Setup:

Colecovision Setup:

MSX1 Setup:

MSX2+ Setup:

Terminal Demonstration:

With AY3-8910 Soundboard:

With SN76489 Soundboard:

Components

Project Logs

Collapse

Baffa-2 at RetroRio 2022

Baffa-81: Running ZX81 on Baffa-2 Homebrew Computer

Baffa-2 ZX81 Boards on its way!

Baffa-X: MSX1 Compatible Computer tested!

Apple-1 Running on Baffa-2

Baffa-6502 plays Atari 2600 games

Baffa-X Boards - MSX1 Compatible Computer

Baffavision: Playing Colecovision games on Baffa-2 Homebrew Computer