Mostly as a recreation I got the sources for that venerable game (it
was written with old BASIC) and I modified it for a modern BASIC,
namely the FreeBASIC (see http://www.freebasic.net and
http://www.freebasic.net/wiki/).
The Windows binary is
http://www.tkk.fi/~ajy/FreeBASIC/ST.EXE
and the source code as BASIC is
http://www.tkk.fi/~ajy/FreeBASIC/ST.BAS
regards, Mr Antti J Ylikoski, Helsinki, Finland, the EU