Sinc I just joined the GAP-forum, I don't know about "the
kbhit()-problem". Could you tell me what that was?

The DJGPP version was spending a rather large proportion of
its time switching back into 8086 mode to check if a key had
been pressed (in case it was an interrupt key). By reducing
the frequency of such tests (see the GAP-3.2 sysdos.c) a
substantial performance improvement was acheived.

Steve