Epson ActionDesk 4000 User Manual page 121

M e m o r y
R O M
video RAM
Shadow RAM
M e m o r y
relocation
C a c h e
M a t h
coprocessor
Clock/
calendar
A-2 Specifications
4MB RAM standard on a SIMM;
expandable to 64MB using 1MB, 2MB,
4MB, 8MB, 16MB, and 32MB SIMMs;
SIMMs must be tin-plated, 72-pin, 32-bit
or 36-bit, fast-page mode type with access
speed of 80ns or faster
128KB Phoenix@ system BIOS, video BIOS,
and SETUP code located in EPROM on
main system board
1MB DRAM on main system board;
expandable to 2MB using two ZIP chips
Supports shadowing of system and video
BIOS ROM into RAM
Supports relocation of 256KB of memory
from AOOO0h to BFFFFh and D0000h to
EFFFFh to extended memory
8KB of internal cache; supports 64KB,
128KB, or 256KB of external cache using
28-pin, 8 x 8, 20ns DIP chips or 28-pin,
32 x 8, 20ns DIP chips
Math coprocessor built into the
microprocessor for DX, DX2, and systems
upgraded to a Pentium OverDrive
processor.
Contained in the 82C491 system controller
chip along with 64 bytes of CMOS RAM
backed up by a soldered NiCad
rechargeable battery