IBM RT PC 10 Hardware Maintenance And Service page 155

3-110 Service Manual
19x
FRU: Floating-Point Board
Additional Tests: Run the Floating Point Accelerator Checkout.
Removal Procedure: See "Processor, Floating-Point, or System
Memory Removal" on page 4-14.
Repair Checkout: Run the Floating Point Accelerator Checkout.
20x
FRU: Personal Computer AT Coprocessor Option
Additional Tests: None
Removal Procedure: See "Adapter Removal" on page 4-16.
Repair Checkout: Run the Personal Computer AT Coprocessor
Option Checkout.
21x
FRU: AT 512 KB Memory Expansion Option
Do not return to the Start of Call PIC, go to "Memory Expansion
Option PIC 2100" on page 3-62.