Mitsubishi Electric Apricot Owner's Handbook Manual page 158

BIOS Page Register 120h (write only)
This controls the BIOS and SRAM paging. All bits are cleared on reset.
When the Flash disk/SRAM decoding is disabled, the BIOS has a page
size of 32 Kbytes. Bit 4 of the Control Register = 0.
Bits Function
7:3 n/a
2:1 BIOS page (0
0 n/a
When Flash disk/SRAM decoding is enabled, the BIOS has a page size
of 16 Kbytes. Bit 4 of the Control Register = 1
Bits Function
7:3 n/a
2:0 BIOS page (0
DOS Flash Page Register 121h (write only)
This controls the Flash disk paging. All bits are cleared on reset.
Bits Function
7:0 Flash disk page (0
T e c h n i c a l I n f o r m a t i o n
3)
7)
255)
OWNER'S HANDBOOK 5-43