Epson 486SX - Manual (Page 204)

System Memory Map
02000000h 16MB
(Maximum system
memory on SIMMs)
Extended memory
OO1OOOOOh 1MB
System BIOS ROM: 64KB*
000F0000h
VGA BIOS: 32KB*
000E0000h
Available
000D0000h
Available
000C0000h
Video memory: 64KB (MDA or CGA)
000B0000h
Video memory: 64KB (EGA or VGA)
000A0000h 640KB
Conventional system memory: 640KB
00000000h
l
The system BIOS and VGA BIOS are contained in one 128KB EPROM. The
64KB system BIOS and 32KB VGA BIOS ROM are shadowed in RAM after
the system completes power-on diagnostics. The system and VGA BIOS
ROM area in the 000E0000h through 000F0000h range is shadowed at
000E0000h after the system completes power-on diagnostics.
D-6 Specifications