Example?

http://wasiliy.myftp.org/space.zip

"procedure schiffe" contains the patterns and "procedure init_schiffe" is supposed to write the patterns to video ram. It worked back then when I had Windows 98. So I don't think that it's a problem with the code.

INT 10/11 works fine, but your program is not managing the segment for the character patterns correctly in the context of a protected mode program. ES is destroyed after the DPMI provider switches to real mode and calls DOSBox's INT 10 handler. Maybe a simple solution is to compile for a real mode executable.

Right, the fact that the game is buggy is hidden by w98's dpmi host,
it does not work on a real dos system.

Oh, sorry then. I must admit that I've never worked with a real dos system =)

I'll try writing directly to VGA memory.