Technical data

Troubleshooting
Chassis Test Codes
4-26
4 In the `Replace’ column, the system board is listed as the assembly to replace.
If the chassis code indicates a normal function or test, but the board computer is not
continuing on with its process, the assembly listed in the `Replace’ column should be
replaced.
5 Replace the Model 743 system board to repair the board computer.
Chassis Code Terms
Table 4-8 shows the abbreviations used in the chassis codes.
Table 4-8 Chassis Code Terms
ALU Arithmetic logic Unit
CPU Central Processing Unit
DTLB Data Translation Lookaside Buffer
FLT Floating-Point Co-Processor
IODC I/O Dependent code
IPL Initialize Program Loader
HPMC High Priority Machine Check
MIOC Memory and I/O Controller, part of the CPU chip
PDC Processor-Dependent Code
TLB Translation Lookaside Buffer
TOC Transfer of Control