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PB450 Cache Upgrade

Caution Only authorized service personnel should upgrade the system. Anyone who wants to upgrade the system themselves should know about the dangers of ESD (Electro-Static Discharge) and the necessary precautions. Unknowingly zapping the components of the computer will void the warranty.

Component Locations
The Cache and TAG RAM are either 28-pin for 128KB of cache, or 32-pin for 512KB of cache.

Purchase Referrals
End users should contact end user Service for cache modules. The part numbers are as follows
 
B093    128K
B096    512K

(The 512K set is available through C/S, however, end user may purchase part W241024AK-20 9402
Manufacturer Winbond from any mail order catalog co.).

CACHE CHIP TYPE 128K 512K
Tag SRAM (U55) One 32Kx8, 15ns One 32Kx8, 15ns
DB SRAM (U57/58) One 64Kx1, 15ns One 64Kx1, 15ns
  Four 32Kx8, 20ns Four 128Kx8, 20ns