Installing External Cache - Epson ActionDesk 4000 User Manual

Installing External Cache

You can install 64KB, 128KB, or 256KB of external cache on
your system.
To install 64KB of external cache, use eight SRAM, 28-pin,
8 x 8, 20ns DIP chips, and one 8 x 8, 20ns tag chip
To install 128KB of external cache, use four SRAM, 28-pin,
32 x 8, 20ns DIP chips, and one 8 x 8, 20ns tag chip
To install 256KB of external cache, use eight SRAM, 28-pin,
32 x 8, 20ns DIP chips, and one 32 x 8, 20ns tag chip
To install any cache on a 486DX/50 system, make sure the
tag chip is a 15ns chip.
For the cache memory to work properly, you must install chips
in the following configuration (each bank contains four cache
memory sockets):
Cache memory configurations
BANK0
U20,21,22,23
8 K x 8
3 2 K x 8
3 2 K x 8
4-22 Installing and Removing
BANK1 Tag SRAM
U36
U29,30,31,32
8 K x 8
8 K x 8
8 K x 8
X
3 2 K x 8 3 2 K x 8
Options
Total cache
64KB
128K8
256KB