INT 14 - PC-MOS/386 v5.01 $serial.sys v5.04 - OUTPUT CHARACTER, WITH TIMEOUT
        AH = 21h
        AL = char to send
        DX = port number
        SI = timeout in timer ticks (0000h = default)
Program: PC-MOS/386 v5.01 is a multitasking, multiuser MS-DOS 5.0-compatible
          operating system by The Software Link, Inc.
SeeAlso: AH=01h,AH=0Eh"PC/MOS",AH=22h"PC-MOS"

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