MSX2 Computer Panasonic FS-A1 and mods


I am friends with a fellow local retro collector who has an amazing collection of MSX games and software – check out I own a Spectravideo 728 which is MSX compatible, but you really need an MSX2/MSX2+ to be able to play most of the best games on offer. So in a recent trip to Japan I found a cheap MSX2, the Panasonic FS-A1. For about $25 AUD it was a junk item with no power supply. It is also somewhat of a “low end” MSX2, however all I want to do is play games so it is perfect for that. Now I can see what all this fuss is about for MSX computers.

Here it is. I think a nice looking machine. So there are a few things I need to do to see if it works, and if so some further mods/ accessories to get the most out of it.

Firstly, the power supply. The issue for this model of MSX is that the power supply outputs 9VDC & 18V AC which is not common. Then there is the power connector which is an unusual 3 prong triangle shape. These power supplies are like hens teeth to get hold of, and hence attract a high price when sold on auction sites. The Sony HB-F1 also uses the same spec power supply.

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I am going to make a power supply as a future project. For now I have another local friend with a Sony HB-F1 so I could borrow their power supply to try the MSX out. They were also kind enough to lend me a MegaFlashRom cart so I could try out some games.

A quick test with composite cables had the MSX booting into the inbuilt DeskPac software, which meant it was working. Now time to make a few mods to improve things!

RGB Cable

The FS-A1 MSX puts out RGB natively and the pin out for it is the MSX standard. So using the pinout from MSX.Org
I built a cable using a 8 pin “C” shaped DIN. As always RGB output looks great.



8 pin din – looking into back of connector

Completed cable

Firmware removal

The Deskpac firmware serves no real purpose for me. Doing some investigation it is recommended to remove it. Reading through the MSX.Org forum I found a helpful thread on how to to this.

Opening up the case and carefully removing the keyboard ribbon connectors, the chip we want to remove is IC3.

There are a bunch of screws on the motherboard which need to be removed. Helpfully there are screw indicators on the board to show you where to put them back. Carefully flipping the motherboard over, located the solder points of the existing rom chip.


Before using your desoldering method of choice, add some new solder to the chip legs to make it easier to melt and remove.


I used my trusty Hakko desoldering gun to remove the existing room, which made easy work of the removal.


I soldered a new socket in place, and burned a spare 27c512 eprom with the modified firmware with a VP-280 programmer.

Testing again, now the MSX boots straight into basic. If I ever want to put the old firmware back, I just need to remove the existing chip from the socket and drop the old one in.


MSX to Sega Master system controller adapter

I don’t have any specific MSX compatible controllers, however it is easy to make adapters so you can use Sega Controllers. I specifically chose to make an adapter so I could use Sega Master System controllers.

The pinout is very similar, so only minor wiring is required in the adapter.

Pins 1-5 & 8 are connected straight through. Master System Pin 6 connecting to MSX pin 7, and Master System pin 9 connecting to MSX pin 6 being are the only connections to be mapped differently for the buttons.

I cut off a joystick cable from a non work working old joystick, stripped the wires and connected to a new 9 pin male plug with housing.

The completed cable.

Ok now to play some great MSX titles from the flash cart! Over 3000 titles published for MSX, many great classics to be discovered. Here are a few of the first I have loaded up.

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