Installing External Cache

You can install either 32KB or 128KB of external cache on your system. Use five DRAM, 28-pin, 8 x 8,20ns or 25ns DIP chips to install 32KB or five 256 x 4,20ns DIP chips to install 128KB of external cache on your system.

1.Locate the external cache sockets on the main system board, shown on page 3-5.

2.If there is an option card in your way, remove it. See page 3-17 for instructions.

Caution

To avoid generating static electricity and damaging the cache chips, ground yourself by touching the metal surface on the inside of the computer’s back panel. Then remain as stationary as possible while you install them.

3.Remove the cache chips from their package and inspect them. The pins should point inward at slightly less than a 90° angle.

If any of the pins are bent, straighten them gently with your fingers or with small tweezers to align them with the other pins. Be careful when you do this; the pins are fragile and can break off easily.

3-22 Installing and Removing Options