Epson SQ-B50/2550 Technical Manual page 266

REV.-A
A.1.1.3 E05A21AA
• Lower address latch, and out put
• Bank latch output
• Bit caluculation
• MMIO address decode, MMIO signal output
• Character genelator, PROM, RAM decode and chip enable signal output
• Select built-in PROM / external PROM
• Reset signal generator (power on reset / cartridge mount, dismount)
• ON LINE SW state reading
7FFFF
7FDOO
60000
(BANK)
40000
20000
10000
00000
MMIO
RAM
OOH-3FH 40H-1FH 80H-BFH COH-CFH DOH-DFH EOH-EFH FOH-FFH
CGO CGl KCG KCGO CAO CAl
RAM
256KB 256KB 256KB 256KB 256KB 256KB 256KB
X X X
X
X X
X
64
64 64 16 16 16
16
EXTERNAL
PROGRAM
INTERNAL
PROGRAM
l28K
256K
64K
64K
Figure A-7. E05A21AA Memory Map
A-8