[This file was provided by Wim Osterholt (2:512/56 or wim@djo.wtm.tudelft.nl).]
Last Change: 11/6/94
XT, AT and PS/2 I/O port addresses
Do NOT consider this information as complete and accurate.
If you want to do harware programming check ALWAYS the
appropriate data sheets. Be aware that erroneously programming
can put your hardware or your data at risk.
There is a memory mapped address in use for I/O functions of which I
think it should be mentioned here. See at the end of this list.
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0000-001F ---- DMA 1 (first Direct Memory Access controller 8237)
0000 r/w DMA channel 0 address byte 0, then byte 1.
0001 r/w DMA channel 0 word count byte 0, then byte 1.
0002 r/w DMA channel 1 address byte 0, then byte 1.
0003 r/w DMA channel 1 word count byte 0, then byte 1.
0004 r/w DMA channel 2 address byte 0, then byte 1.
0005 r/w DMA channel 2 word count byte 0, then byte 1.
0006 r/w DMA channel 3 address byte 0, then byte 1.
0007 r/w DMA channel 3 word count byte 0, then byte 1.
0008 r DMA channel 0-3 status register
bit 7 = 1 channel 3 request
bit 6 = 1 channel 2 request
bit 5 = 1 channel 1 request
bit 4 = 1 channel 0 request
bit 3 = 1 channel terminal count on channel 3
bit 2 = 1 channel terminal count on channel 2
bit 1 = 1 channel terminal count on channel 1
bit 0 = 1 channel terminal count on channel 0
0008 w DMA channel 0-3 command register
bit 7 = 1 DACK sense active high
= 0 DACK sense active low
bit 6 = 1 DREQ sense active high
= 0 DREQ sense active low
bit 5 = 1 extended write selection
= 0 late write selection
bit 4 = 1 rotating priority
= 0 fixed priority
bit 3 = 1 compressed timing
= 0 normal timing
bit 2 = 1 enable controller
= 0 enable memory-to-memory
0009 w DMA write request register
000A r/w DMA channel 0-3 mask register
bit 7-3 = 0 reserved
bit 2 = 0 clear mask bit
= 1 set mask bit
bit 1-0 = 00 channel 0 select
= 01 channel 1 select
= 10 channel 2 select
= 11 channel 3 select
000B w DMA channel 0-3 mode register
bit 7-6 = 00 demand mode
= 01 single mode
= 10 block mode
= 11 cascade mode
bit 5 = 0 address increment select
= 1 address decrement select
bit 3-2 = 00 verify operation
= 01 write to memory
