MSX1 Homebrew Clone for Baffa-2 Project

Description

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, Clock and TMS9918 Boards from Baffa-2.

Baffa-2 is an educational and personal project with the aim of understanding how computers work through 80's 8-bit commercial machine designs. It has a modular concept with boards that can be combined to develop your own design and configuration.
More info: https://hackaday.io/project/183266-baffa-2-homebrew-microcomputer

Details

After the Baffavision project and reading some notes by J.B. Langston, I realized that I could continue studying to make Baffa-2 an MSX clone. I already had CPU, VDP (video card), PSG (sound card), clock and base memory (64KBs), so I just had to put it all together with a parallel peripheral interface (PPI) msx.

In Brazil, we only had contact with MSX1. There were some national kits to upgrade it to an MSX2 but most people didn't upgrade at the time. For this reason, I thought of creating a clone of what we had contact with and based it on the schematics of one of our main machines: Sharp's Hotbit (HB-8000).

I still plan to add a serial via wifi to be able to connect it to the internet and the printer interface card (using DB29 connector). In the future I also see that it is possible to create a memory mapper and a VDP using the v9958 chip, which will allow compatibility with MSX2.

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

Other Acknowledgments:

PS/2 Keyboard matrix firmware is adapted from Danjovic's EXPS/2 project code
TMS9918 VDP is based on J.B.Langston's Game Boards for RC2014
AY-8910 PSG is inspired on Ed. Brindley's YM2149F/AY-3-8910 sound card for RC2014
Baffa-X IDE is an adaptation of Egor (SOLID) Voznesensky's Beer 202 ATA IDE for MSX

MSX-2+ Setup:

I've been working on a MSX upgrade during last months and between february and april I got stuck due to many v9958 fake chips. I could have everything working in early April and define the organization of the boards after testing. MSX2 uses VDP v9938 while MSX2+ uses VDP v9958 and has a real time clock. Unfortunately the Beer 202 IDE does not have ROM support for MSXDOS2 and it was necessary to replace it with an interpretation of Sunshine IDE.

Project Logs

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MSX1 and MSX2+ together...
Augusto Baffa • 10/14/2023 at 22:43 • 0 comments

When I was assembling all the PCBs for my MSX2+ project, I used all the compatible PCBs that were available in the MSX1. And since there were still the VDP 9918, the Beer IDE and the 64KB Ram from MSX1 project, why not build another one?

To do this, it was necessary to assemble a new Clock, CPU, PPI, Clock and PSG.... PCBWAY minimum order is 5 pieces, so I still have some spare parts :)...

Above MSX2+... Below (and connected to monitor) MSX1
Baffa-X (MSX) using Wifi Modem
Augusto Baffa • 04/09/2023 at 22:26 • 0 comments

Baffa-X (Baffa-2 with MSX Boards) now has a Wifi Modem based on 16550 and Esp32. It's similar to original Baffa-2 SIO Board and compatible to BadCat Card software/terminal.
Aleste Music using FM-PAK + PSG on Baffa-X
Augusto Baffa • 04/07/2023 at 19:53 • 0 comments
It's Alive - Baffa-X2 (MSX-2+)
Augusto Baffa • 04/06/2023 at 00:28 • 0 comments

Finally, I could test all the boards together. Now, it's possible to upgrade the Baffa-X from MSX1 to MSX2+. It replaces the VDP v9958 (compatible with other Baffa-2 projects), Memory of 64KB by 1MB Ram Board (megaram) and adds Rom/SlotExpansion and RTC Boards.
Finally an original V9958! 8th order!
Augusto Baffa • 04/05/2023 at 21:16 • 4 comments

As we know, the V9958 package has no notch (hole). All fake V9958 have the same code 2703 2122 IACC, and we can notice the painting of the label that is different. (the last one at bellow is the original IC)
Another V9958 Fake (this time) received from UTSource
Augusto Baffa • 04/04/2023 at 18:07 • 0 comments
Baffa-X (Baffa-2 MSX1) at MSXRio Mar-23
Augusto Baffa • 04/04/2023 at 18:05 • 0 comments
Lots and Lots and Lots of Fake v9958
Augusto Baffa • 03/25/2023 at 23:41 • 1 comment

Hi folks,

bad news. The retro market is flooded by rebranded v9958 fake chips. I bought six already from different Aliexpress stores and all came with the same serial and "notch". As we know, the package of yamaha v9958 has no notch. (Example on figure bellow)

For while, I tried those six I received from Aliexpress stores. All have the same code and manufacturing date:

It seems that the are rebranding "toshiba" 64 pin ics like 68000 or 1253. Compare for yourself....

Unfortunately, this is leading to a price dispute and ruining the MSX2+ spare parts market. And this project is stopped waiting for a part that works.

My first v9958 was about 10 usd on august, 2022. ... Today (march, 2023) I got a quote of 111 usd from utsource.
MSX2 Setup coming soon
Augusto Baffa • 02/23/2023 at 12:05 • 0 comments

The new MSX2 setup is coming soon.
1MByte Memory Mapper on Baffa-X
Augusto Baffa • 02/22/2023 at 03:09 • 0 comments

1MByte Memory Mapper working correctly. This board is part of the new set of boards to transform the Baffa-2 MSX1 into an MSX2(+) compatible computer.
I'm waiting for the missing components to arrive to finish the other boards. News coming soon.