.sp
F0: requires set wheel byte (Backgrounder II)
.br
-F1: public file (P2DOS, ZSDOS), forground-only command (Backgrounder II)
+F1: public file (P2DOS, ZSDOS), foreground-only command (Backgrounder II)
.br
F2: date stamp (ZSDOS), background-only commands (Backgrounder II)
.br