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AcerAltos 900 User’s Guide
A-2
A.2
I/O Address Map
Table A-2
System I/O Address Map
Address Range (hex)
Device
000 ~ 01F
DMA controller 1
020 ~ 027
Interrupt controller 1
030 ~ 037
Interrupt controller 1
040 ~ 047
System timer
050 ~ 057
System timer
060 ~ 06F
Keyboard controller
070 ~ 07F
Real-time clock, NMI mask
080 ~ 09F
DMA page register/speed status register
0A0 ~ 0BF
Interrupt controller 2
0C0 ~ 0DF
DMA controller 2
0F0
Clear math coprocessor
0F1
Reset math coprocessor
0F8 ~ 0FF
Math coprocessor
4F0
AEN4 enables (onboard VGA enabled)
Flash ROM programming
IRQ12 enabled
3.5-inch diskette 3 -mode selection
DMA channel 1 selection
DMA channel 3 selection
4F1
ASM data read/write port
4F2
ASM index write port
0CF8
PCI configuration address regulation
Summary of Contents for Altos 900
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