HP 7942 Service Manual page 96

Table 4- S. Diagnostic Summary
UNIT 0 AND UNIT 2 SELF TEST
SELF TEST
1. 78 Sub tests. Subtests indicated on rear panel 2-digit hexadecimal display
Subtest code range: OA-68H (unit 0), 00-07, 88 (unit 2).
2. 16 supplementary error condition codes. Error code range; 30- 3F.
SELF TEST REPORTING, UNIT 0 and UNIT 2
1. Front pa.nel FAULT/ON LINE indicator: pass/fail.
2. Rear panel 2-digit hexadecimal readout:
• Failed unit.
• Failed FRA(s).
• Failed subtest.
SELF TEST REPORTING, UNIT 0
1. QSTAT=1
2. REQUEST STATUS message format:
• Bit 24 set
• P 1: Most likely failed FRA
• P2: Second most likely failed FRA
• P 3: Failed subtest
• P7: Failed error condition
• P8: Supplementary error codes - data error byte,
disc controller Ie error
register, fault code list, number of seeks, and
disc controller Ie status register.
UNIT
O~
RUN TIME ERROR AND FAULT REPORTING
RUN TIME ERROR AND FAULT REPORTING
1. QSTAT=l.
2. REQUEST STATUS message format:
• Bit 24 not set.
• P7: Fault code list
• P 8: Supplementary error codes - disc controller Ie
e:rror and status registers.
3. Log entries
• All faults/data error codes logged in fault log/data error log.
• Data error address, status byte occurrence count logged in
run log.
Service Information
7942 and 7946
4-27