msx

8 Articles

Building A DIY MSX Mega Cartridge

September 7, 2024 by 9 Comments

[Mike] from Leaded Solder has a soft spot for old computers, and a chance encounter with a friend sent them deep down the deep hole that is the world of 80s and 90s-era Japanese home computers.  Many people playing with these machines have all kinds of issues to deal with, such as rotting cartridges, failing components, and just dirt and mank in critical places. [Mike] decided that working on an MSX-standard custom programmable cartridge would be sensible, but then got stuck on how the MSX cartridge mapping works.

The Konami 128K scheme uses 4 to 4-of-8 mapping.

You may recall that the MSX platform is not a single computer but a standard to which many (mainly Japanese) manufacturers designed their products. This disconnected the software writers from the hardware makers and is essentially a mirror of the IBM-PC clone scene.

The MSX is based around the Z80, which has a 16-bit address bus, restricting it to 64K of ROM or RAM. The MSX has two cartridge slots, an ‘internal’ slot for the BIOS and RAM and a fourth for ‘misc’ use. Each of these is mapped internally into the physical address space. The cartridge slots have 64K of addressable space mapped into the Z80 physical space.

If this was not complicated enough, many MSX games and applications exceeded this restriction and added a layer of mapping inside the cartridge using bank switching. A register in the cartridge could change the upper bits of the address allowing ROMs larger than 64K.

Continue reading “Building A DIY MSX Mega Cartridge” →

A "portable" computer in a grey enclosure. There is a small CRT on the left hand side of the face of the enclosure and a disk drive and a couple ports exposed on the right hand side. The keyboard is attached with a purple cable. A black cartridge with a grey and red label sticks out of the top of the enclosure.

Portable MSX2 Brings The Fun On The Go

April 11, 2023 by 6 Comments

Something of a rarity in the US, the MSX computer standard was rather popular in other parts of the world but mostly existed in the computer-in-a-keyboard format popular in the 80s. [Aron Hoekstra aka “nullvalue”] wanted to build an MSX2 of their own, but decided to build it in a period-appropriate luggable form factor.

This build really tries to make the computer as plausibly vintage as possible including an actual CRT for the display instead of using an easier to obtain and package LCD. Computing is accomplished with an Omega Home Computer MSX2 SBC by [Sergey Kiselev] which uses components that could have been found when the MSX computers were in production. While 3D printing wasn’t widespread in the 80s, we can assume any of the plastic parts like the internal mounts would have been injection molded instead.

An impressive number of different techniques were used to bring this computer to life including PCB design, 3D printing, CNC, and plenty of soldering. After some troubleshooting on the 50 pin cartridge connector and all the assembly, [Hoekstra]’s Mega Omega MSX2 Portable Computer makes for a very impressive reimagining of the MSX platform that feels like a product that might have actually existed at the time.

If you want more MSX hacks, checkout how to add a Wii Nunchuck or PS2 or USB keyboards to your MSX.

Continue reading “Portable MSX2 Brings The Fun On The Go” →

EXPS/2 Keyboard Adapter Translates PS/2 And USB To MSX

August 2, 2021 by 9 Comments

Say what you will about suitcase computers, but at least most of them still have their keyboards with them. [danjovic] has this vintage Brazilian computer from the 1980s called a Gradiente Expert. These were MSX machines with Z80 chips that ran BASIC, DOS, and CP/M, and they looked like state-of-the-art dual-deck stereo systems. You can still find them pretty easily, but sadly, most of them have lost their rad mechanical keyboard with its giant arrow keys and proprietary connector.

If you now want to get one of these awesome pieces of computing history and would like to be able to talk to it, [danjovic] has you covered with the open-source EXPS/2 keyboard adapter. It will allow you to connect either a PS/2 keyboard or a USB keyboard in fallback mode to the Expert using an ATMega328P and a bespoke DIN-13 to DB-13 cable. As it turns out, there’s a wealth of information on MSX keyboard matrices out there.

How much do you know about the USB keyboard interface? If you want a warehouse of information delivered to your brain in the most pleasant way possible, go watch [Ben Eater] break it down with pen and paper.

An MSX With A Nintendo Controller

August 12, 2019 by 5 Comments

Console owners inhabit their own individual tribes depending upon their manufacturer of choice, and so often never the twain shall meet. But sometimes there are those what-if moments, could Mario have saved the princess more quickly through PlayStation buttons, or how would Sonic the Hedgehog have been with a Nintendo controller? [Danjovic] is finding the answer to one of those questions, with an interface between Nintendo 64 controllers and MSX hardware including the earlier Sega consoles.

In hardware terms, it’s a pretty simple device in the manner of many such projects, an Arduino Nano, a resistor, and a couple of sockets. The clever part lies not in its choice of microcontroller, but in the way it uses the Nano-s timing to ensure the minimum delay between button press and game action. The detail is in the write-up, but in short it makes use of the MSX’s need to attend to video lines to buy extra time for any conversion steps.

The MSX computers have had their share of controller upgrade courtesy of Nintendo hardware in the past, we’ve seen a Wii nunchuck controller talk to them before, as well as a SNES one.

Header image: [mboverload] (Public-domain).

Raspberry Pi Cyberdeck Inspired By Rare MSX

July 16, 2019 by 11 Comments

When we see these cyberdeck builds, the goal is usually to just make something retro-futuristic enough to do William Gibson proud. There’s really no set formula, but offset screens coupled with large keyboards and a vague adherence to 1980s design language seem to be the most important tenets.

Granted the recent build by [lewisb42] still leans heavily on those common tropes, but at least there’s a clear lineage: his Raspberry Pi retro all-in-one is styled after a particularly rare bright red variant of the MSX that Sony released in Japan. Known as the HIT-BIT HB-101, some aficionados consider the circa-1984 machine to be the peak of MSX styling. Since getting his hands on a real one to retrofit wasn’t really an option, he had no choice but to attempt recreating some of the computer’s unique design elements from scratch.

The faceted sides were 3D printed in pieces, glued together, and then attached to a 1/4″ thick backplate made out of polycarbonate. For the “nose” piece under the keyboard, [lewisb42] actually used a piece of wood cut at the appropriate angles with a table saw. The top surface of the computer, which he calls the FLIPT-BIT, is actually made of individual pieces of foamed PVC sheet.

If all this sounds like a big jigsaw puzzle, that’s because it basically is. To smooth out the incongruous surfaces, he used a combination of wood putty, body filler, spot putty, and more time sanding then we’d care to think about. For the 3D printed surface details such as the screen bezel and faux cartridge slots, he used a coat of Smooth-On’s XTC-3D and yet more sanding. While [lewisb42] says the overall finish isn’t quite as good as he hoped, we think the overall look is fantastic considering the combination of construction techniques hiding under that glossy red paint job.

As for the electronics, there’s really no surprises there. The FLIPT-BIT uses a keyboard and touchpad from Perixx, a seven inch TFT display, and of course the Raspberry Pi 3. The display runs at 12 V so [lewisb42] used a combination of a generic laptop-style power supply and a 5 V step-down converter to keep everyone happy. While it doesn’t currently have a battery, it seems like there’s more than enough room inside the case to add one if he ever wants to go mobile.

If this build doesn’t properly scratch your Neuromancer itch, never fear. Just take a look at this decidedly less friendly-looking build that even includes a VR headset for properly jacking yourself into the matrix.

Pitting 8-Bit Chess Games Against Modern Foes

May 23, 2019 by 19 Comments

UltraChess is a vintage chess game for the 8-bit MSX platform, running on the Z80. [flok] wondered just how capable the game really was, and set forth to test it against a variety of other chess engines.

Having been designed in the 1980s, UltraChess is far from up-to-date as far as the chess software world is concerned. By using the OpenMSX emulator to run the game, [flok] was able to implement scripts to read and write the gamestate in UltraChess, and make it compatible with the Universal Chess Interface. This would allow UltraChess to be played off against a variety of other chess engines to determine its approximate ELO rating.

The scripts worked well, and are available on Github for those who wish to tinker further. Unfortunately, [flok] has thus far been unable to determine a rating for UltraChess, as it has lost every single game it has played against other chess engines. This is unsurprising given the limited processing power available, but we’d love to see a tweaked and hotrodded Z80 chess program take on the same challenge. If you’ve done such a thing, let us know, or alternatively  you might like to try playing like Harry Potter.

An Old Video Game Controller On Even Older Computer

October 6, 2017 by 13 Comments

For those of us not old enough to remember, and also probably living in the States, there was a relatively obscure computer built by Microsoft in the early 80s that had the strong Commodore/Atari vibe of computers that were produced before PCs took over. It was known as the MSX and only saw limited release in the US, although was popular in Japan and elsewhere. If you happen to have one of these and you’d like to play some video games on it, though, there’s now a driver (of sorts) for SNES controllers.

While the usefulness of this hack for others may not help too many people, the simplicity of the project is elegant for such “ancient” technology. The project takes advantage of some quirks in BASIC for reading a touch-pad digitizer connected to the joystick port using the SPI protocol. This is similar enough to the protocol used by NES/SNES controllers that it’s about as plug-and-play as 80s and 90s hardware can get. From there, the old game pad can be used for anything that the MSX joystick could be used for.

We’ve seen a handful of projects involving the MSX, so while it’s not as popular as Apple or Commodore, it’s not entirely forgotten, either. In fact, this isn’t even the first time someone has retrofitted a newer gaming controller to an MSX: the Wii Nunchuck already works for these machines.