User`s guide

Installing External Cache
You can install 64KB, 128KB, or 256KB of external cache on
your system.
P To install 64KB of external cache, use eight SRAM, 28-pin,
8x8, 20ns DIP chips, and one 8x8, 20ns tag chip
0 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
Q 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
0 To install any cache on a 486DX/50 system or a system
with a Pentium OverDrive processor, make sure the tag
chip is a 151ns 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 BANK1 Tag SRAM
U44,45,46,47
U48,49,50,51 U43
Total cache
8Kx8 8Kx8 8Kx8
64KB
I
32Kx8
I
(empty)
I
8Kx8
I
128KB
I
32Kx8 32Kx8 32Kx8
4-22 Installing and Removing Options