Loop-Back Tests - IBM 9348 Service Information

Diagnostic Test 54 (Master Dual-Port Direct-Access Storage [DPR] Interrupt Test)
Parameter A = 0, 3, or 4.
This test verifies the ability of the dual-port direct-access storage (DPR) to operate
with interruptions.
Loop-Back Tests
Diagnostic Test 60 (Interface Loop-Back Test)
Parameter A
=
loop-back check number.
Parameter Loop-Back Check
A
0 Run all loop-back checks from 1 through 3
1 Loop-back correct data
2
Data to buffer with a parity error
3 Data from buffer with a parity error
Diagnostic Test 61 (Buffer lnitiated LoopBack Test)
Parameter A = loop-back type.
Data is generated in the buffer then looped through the formatting section of the
readlwrite card, using the multiprocessor loop-back command. Parameter A indi-
cates the extent of the test.
Parameter Loop-Back Check
A
0 Run all loop-back checks from 1 through
5
1
Correct phase encoded (PE) data
2 Correct groupcoded recording (GCR) data
3
Correct groupcoded recording (GCR) data underrun
4 Correct groupcoded recording (GCR) data overrun
5 GCR data with a parity error
Parameter Data Pattern
B
0 All zeros
1
All ones
2 Alternating ones and zeros
3 Rotating 0
-
255
4 Pseudorandom
Diagnostic Test 62 (Tape Unit lnitiated Digital LoopBack)
Parameter A
=
loop-back block type.
Loop-back data or a write pattern is generated by the controller and passed through
the formattinn circuits of the read/write card.
Appendix B. Diagnostic Tests
B-9