Overview Of Address Space - HP Vectra XU5 Reference Manual

Overview of Address Space

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).
Vectra XU Technical Reference Summary of the HP BIOS 44