;
-; this routine updates errno. do a JMP here right after calling
-; CIOV. we expect status in Y.
-; __retminus is a routine with returns AX with $FFFF
+; __do_oserror updates __oserror. Do a JMP here right after calling
+; CIOV. It will return with AX set to -1 ($FFFF). It expects the CIO
+; status in Y.
+;
+; __retminus is a routine whitch returns with AX set to -1 ($FFFF).
;
.include "errno.inc"