Compaq 164LX Manual De Usuario
Interrupts and ISA Bus Addresses
6–3
ISA I/O Address Map
6.2.1 Flash ROM Address Map
The address range for the flash ROM is FFF8.0000–FFFF.FFFF. Flash space of 1MB
is obtained by double mapping this 512KB space. FLASH_ADR19 register at I/O
location 800
is obtained by double mapping this 512KB space. FLASH_ADR19 register at I/O
location 800
16
provides this function. Writing a 0 to this location enables the lower
512KB of flash. Writing a 1 to this location enables the upper 512KB of flash.