ASCII8, ASCII16, Konami, Konami SCC - all these names are well known in the MSX community. These are so-called "mappers" that allow games larger than 64kb to work on our favorite MSX computers. The mapper technology requires additional electronic components to be used on a cartridge board. Those could be custom chips by Konami that incorporate mapper and SCC sound or special ASCII8/16 mapper chips. Those chips are impossible to buy these days. So, if your cartridge has a broken mapper chip, it's unlikely that you can fix it.

There are several available multimapper cartridge solutions. And each solution has its pro and contra, but most of the universal solutions require either CPLD or FPGA chips. Those chips are expensive and hard to come by these days. And they are hard to place on circuit boards. How to make things easy for everyone? There is an answer! The new member of RBSC - Pyhesty - decided to help the community. He has created a project called "Unimapper" that uses commonly available PLD (programmable logic) chips and a FlashROM. Very simple and effective solution!

The Unimapper project allows the cartridge to be assembled in 2 different variants - with 2 or 3 PLD chips. By reprogramming those chips it's possible to support 4 different mappers, that were mentioned above. The cartridge supports up to 512kb EEPROMs, so it's even possible to run Metal Gear 2 from it. Moreover, the v3.0 of the cartridge supports Konami SCC mapper and that opens the doors for DSK2ROM-converted floppy disk images to be put into MSX cartridges.

The project has been released into the RBSC's repository and is available for everyone to try. The board just needs 3 or 4 commonly available chips, a few resistors and capacitors. The chips are in DIP casing, so even an amateur can assemble this cartridge. Feel free to take a look at the project's files in the repository.

As usual, RBSC can give the permission to produce the Unimapper cartridges commercially. Please contact the RBSC's coordinator, if you are willing to make a commercial batch.

Relevant link: Overview on RBSC's website
Relevant link: Unimapper in RBSC's repository

Comments (8)

By norakomi

Paragon (1154)

norakomi's picture

19-07-2022, 08:58

Could you gave an estimation of the price for these cartridges ?

By Sander

Founder (1874)

Sander's picture

21-07-2022, 21:41

Hi Norakomi. that's not how RBSC works. They develop the technology, sometimes they produce a small first batch and that's it. They just publish the files so other people can produce the boards with a license. If you need help with a production run you can contact me and I'll see if something can be arranged with RBSC and other famous MSX users.

By poke-1,170

Paragon (1783)

poke-1,170's picture

22-07-2022, 20:59

hmmmm now that color combination Wink

By cax

Prophet (3741)

cax's picture

28-07-2022, 19:23

Yellow sun and blue skies Running Naked in a Field of Flowers
Seriously, it's a great project, but almost nobody seems to be interested?

By Sebbeug

Champion (406)

Sebbeug's picture

01-08-2022, 15:24

Nice project !
If an order is planned, I am interested in some PCBs...

Question : Is the v3.0 version supports Konami, Ascii8 and Ascii16 mappers if we only use 2 GAL chips ?
Or if i understand, we need v2.0 version for Konami/ASCII8/ASCII16 and v3.0 version for KonamiSCC ?

By norakomi

Paragon (1154)

norakomi's picture

09-08-2022, 12:24

unfortunately I havent gotten a reply from the people I contacted about this.
is there anyone interested in producing/selling these cartridges ?
I'm just curious (but also working on a game which requires a 4MB ascii cartridge)

By Sebbeug

Champion (406)

Sebbeug's picture

10-08-2022, 09:45

I plan to assemble a few units for my personnal use.
I'm waiting an answer about v2 and v3 différences (if possible to use v3 as konami/ascii8/ascii16)

By Mumbly

Expert (126)

Mumbly's picture

11-08-2022, 21:43

I will be interested for sure, certainly the V2 version, this is awesome project !!!!