Installing HSZ80 DIMMs

This document provides detailed instructions for installing and replacing DIMMs (memory modules) in HSZ80 cache modules, which can range from 64MB to 512MB. It outlines separate procedures for Dual-Redundant Controller Configurations and Single Controller Configurations.

Key Common Procedures and Warnings:

1. Electrostatic Discharge (ESD) Prevention: Always wear an ESD wrist strap and ensure it's properly grounded to prevent damage to the cache module.
2. External Cache Battery (ECB) Management: The ECB must be disabled by pressing its disable switch (until the status light stops blinking) before disconnecting the ECB cable or removing the cache module to prevent shorting.
3. DIMM Insertion: Insert DIMMs straight into the socket, ensuring notches align with tabs, then press gently until fully seated and the retaining clips engage.

Dual-Redundant Controller Configuration:

• Removal: Requires connecting to the operational controller, disabling failover (SET NOFAILOVER), and using the FRUTIL utility to select and remove the "other cache module." The process involves quiescing device ports and has a 2-minute time limit for module removal.
• Installation: Utilizes FRUTIL to install the "other cache module" (also with a 2-minute time limit for insertion), connecting the ECB cable, inserting the cache module, and finally re-enabling failover (SET FAILOVER COPY=THIS_CONTROLLER).

Single Controller Configuration:

• Removal: Involves dismounting logical units (and shutting down the host PC for Windows NT), connecting to the controller, shutting down the controller (SHUTDOWN THIS_CONTROLLER), and turning off subsystem power before removing the cache module and DIMMs.
• Installation: Requires inserting the DIMMs and cache module, connecting the ECB cable, restoring power to the subsystem (which auto-enables the ECB), mounting logical units on the host, and setting the subsystem date/time.

The document emphasizes precise steps for using the FRUTIL utility for dual-redundant systems and outlines system shutdown/startup procedures for single controller environments. Visual aids are provided for DIMM insertion and memory configurations.