INT 21 - Novell NetWare 4.0, Alloy NTNX - PRINT SPOOLING
        AH = E0h
        DS:SI -> request buffer
        ES:DI -> reply buffer
        subfunction in third byte of request buffer
            00h spool data to a capture file
            01h close and queue capture file
            02h set spool flags
            03h spool existing file
            04h get spool queue entry
            05h remove entry from spool queue
Return: AL = status