2 ; __do_oserror updates __oserror. Do a JMP here right after calling
3 ; CIOV. It will return with AX set to -1 ($FFFF). It expects the CIO
6 ; __retminus is a routine whitch returns with AX set to -1 ($FFFF).
10 .export __do_oserror, __retminus
13 sty __oserror ; save os dependent error code