Cyrillic fonts on MSX1

MSX computers are not really designed to use different languages. So you must use a version designed for your language. You can still display Japanese characters with a Kanji-ROM but this is limited to software compatible with the Kanji-ROM. There is very little software for MSX1 which exploits it.

There also a recent cartridge from Korea that alow to support the UTF-8 coded texts. It supports Japanese characters and Hangul but I do not know if Cyrillic font is included. I don't know either if it can be used on the MSX1s. In any case, there is no software.

MSX machine contains a default font in its BIOS ROM.
It can be used directly by programs and games.
To change it, you would have to replace the BIOS of your machine (and it will only work with other machines that have the same font).

That say, nothing prevents you from loading your font in memory (cartridge, binary, file, etc.) and using it in your own programs (with the encoding of your choice).
All depends of your needs.

You have the address of the font in the Main-ROM at 0004h.
You just have to extract the second half of the font (first 128 characters are "almost" international).
So you have to copy 128*8 bytes (1 KB) from [0004h] + 128*8.

Similarly, you only need to update the second half the font in VRAM.
Just copy your 1 KB data to Pattern Generator Table address + 128*8.

I think that do the trick to display Russian characters in Basic or MSX-DOS.

PS: You will need to repeat the operation if you change the screen mode as the default font will be reloaded in VRAM.

Russian MSX don't only have Cyrillic fonts as a difference. I think this change is insufficient to properly use Russian programs, PRINT USING can probably cause problems, and it can become a problem for non-Russian programs.

There is also the system variable CGPNT at 0F91Fh which avoids retransferring the font each time the screen mode changes.

I want to thank everyone who helped me with this question. With openMSX, I was able to copy the font map from a Yamaha YIS-503IIR from vram to ram and bsave that block of memory. Then I reversed the procedure on the (real) Canon V-20 with bload -> peek -> vpoke. It works like a charm.

Included is a photo of the language learning program I'm developing (work in progress).

The only thing I have not solved yet is how to use the cyrillic characters on the keyboard of the MSX, like you can on a real YIS-503IIR. The official Russian machine has a toggle button that let one switch between the latin-cyrillic font map. I guess that won't be possible on the Canon V-20.