How to do it properly

How to setup Windows for KOI8-R properly

It is nice if some program support KOI8-R<->CP1251 translation automatically, but:

Such programs are very rare and many interesting Internet software knows nothing about decoding needed.
Emulating KOI8-R via CP1251 is incomplete because charsets are different.

In this situation it will be nice to have KOI8-R as separate Code Page 878 for Windows until some critical mass of decoding programs will be reached.

Really we don't need fonts conforming to KOI8-R charset at all, .TTF from Microsoft is always in UNICODE charset and proper way is using them. The only boundary for Win3.11 is that single .TTF can contain 256 character glyphs only. The only thing that you must do is to add KOI8-R -> UNICODE translation table using \Windows\System\gdi.exe resourse. This resource is simply array with 256 entries of word size: index is ANSI code of character, value is Unicode code. It is RC_DATA with ID=1000 in American Win3.1x, PanEuropean gdi.exe has that resource for some of CP125* code pages as controlled by system.ini:

[boot]
wincodepage=

for Win3.1*. Currently Windows use this resource to translate from CP1251 to UNICODE.

So, proper way to handle KOI8-R for both Win3.11 is not installing KOI8-R fonts, but running some program which can change ANSI -> UNICODE mapping to KOI8-R and restore old values by request or HotKey.

If you understand what this stuff means and have experience in programming under Windows and have enough free time and will to write such program, you will be real hero saving all souls crying for help. Please, contact me in this case.

This material given by Walter Kondrashov <Walt@gecko.crec.mipt.ru>, thanks to him.