Hp I/O Port Map (I/O Addresses Used By The System) - HP Vectra VA6 Technical Reference Manual

For example; if the current year is 1996, the year code would be 1996 minus
1960, which is 36h expressed in BCD.
Week of the ROM BIOS Release
0F000:00FFh = Week of the ROM BIOS release in Binary Coded Decimal
(BCD)
Length = one byte
Encoding is as follows:
nn
where nn is the week in which the BIOS ROMs were released expressed
in BCD. The range is 01h to 52h.
HP I/O Port Map (I/O Addresses Used by the System
Peripheral devices, accessory devices and system controllers are accessed
via the system I/O space, which is not located in system memory space. The
64 KB of addressable I/O space comprises 8-bit and 16-bit registers (called
I/O ports) located in the various system components. When installing an
accessory board, ensure that the I/O address space selected is in the free
area of the space reserved for accessory boards (100h to 3FFh).
This is not BIOS dependent. It applies to the operating system, too.
However, the Setup program can be used to change some settings.
I/O Address Ports
0000h - 000Fh
0020h - 0021h
0040h - 0043h
0060h, 0064h
0061h
0070h
0071h
0081h - 0083h, 008Fh
0092h
1. If configured.
Function
DMA controller 1
Interrupt controller 1
Interval timer 1
Keyboard controller
System speaker
NMI mask register, RTC and CMOS address
RTC and CMOS data
DMA low page register
Alternate reset and A20 Function
4 Summary of the HP/Phoenix BIOS
BIOS Addresses
1
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