User's 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

BANK1

Tag SRAM

U20,21,22,23

U29,30,31,32

U36

Total cache

8Kx8

64KB

32Kx8 X

8Kx8

128K8

32Kx8

32Kx8 32Kx8

256KB

4-22

Installing and Removing

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