TQK50 Q Bus Controller Modules

This Field Change Order (FCO) document, TQK50-I001, provides instructions for upgrading TQK50 Q bus controller modules (M7546) below revision F1.

Key Information:

• Applicability: Required for all 1123 and 1153 systems operating under RSTS 9.2, and modules experiencing memory corruption or boundary crossing issues.
• Objective: Resolve memory corruption caused by bus grant problems and fix issues with phantom device addresses and software messages.
• Procedure: Involves replacing chips at positions E3, E28, and E29 with new components (23-065L1-00, 23-249E5-00, 23-248E5-00) and updating switch settings on component E38. This updates the microcode to REV 4 and hardware to REV 6.
• Safety: Emphasizes the use of a VELOSTAT kit to prevent electrostatic discharge damage to the module.