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PC PORT ASSIGNMENT, Intel 8088, 80C88, 8086, 80286, 80386 CPUs

hex addr.                    Function

0000-000F       8237 DMA controller
0010-001F       8237 DMA controller  (AT, PS/2)
0020-0027       8259A interrupt controller
0020-003F       8259A interrupt controller  (AT)
0040-005F       8253-5 programmable timers
                (note: 0041 was memory refresh in PCs. Not used in PS/2)
0060-0067       8255 peripheral interface
0060-006F       8042 keyboard controller  (AT)
0200-020F       game-control adapter
0210-0217       expansion box (PC, XT)
0278-027F       LPT3
02F8-02FF       COM2
0300-031F       prototype card
0320-032F       hard disk controller
0378-037F       LPT2
03BC-03BF       LPT1
03D0-03DF       CGA, MCGA, VGA adapter control
03F0-03F7       floppy disk controller
03F8-03FF       COM1

  Note: These are functions common across the IBM range. The PCjr, PC
        Convertible and PS/2 (both buses) have enhancements. In some
        cases, the AT and PS/2 series ignore, duplicate, or reassign
        ports arbitrarily. If your code incorporates specific port
        addresses for video or system board control it would be wise
        to have your application determine the machine type and
        video adapter and address the ports as required.