HP 7942 Service Manual page 84

READOUT
(HEX)
OA
OB
OC
OD
OE
OF
10
11
12
13
14
15
16
17
18
19
lA
IB
lC
Service Inf orma tion
7942 and 7946
Table 4- 2. Disc Drive (Unit 0) Self -Test Subtest List
SUBTEST
GROUP 2
pUPa register written and was OFH when read back.
Value read from pUPa register was not value written.
DMA loopback test failed transfer into DMA RAM.
DMA loopback test failed transfer out of DMA RAM.
Write to 2
3
head select line did not set head bit 3 (bit 1 of DDC self -test
register).
Write to
2
3
head select line did not clear head bit
3
(bit
1
of DDC self-test
register).
Device specific PROM read into RAM - subsequent checksum failed.
12
volt threshold bit (bit
0
of DDC self -test register) not set.
Value read from a disc controller IC register not value written.
GROUP 3
Timeout occurred after drive selected while waiting for drive ready status.
Restore Command issued and failed.
Seek completed, seek complete bit is not set in the disc controller IC status,
but is set in bit 3 of DDC self -test register.
Seek command completed, Seek complete not set in either disc controller IC
status or the self -test register.
Seek command failed, disc controller IC status register indicates reason.
Seek command failed, disc controller IC error register indicates reason.
Seek completed, but pulse count was not
I,
as expected.
Seek completed, but pulse count was not 15 as expected.
Seek completed, but the direction bit (bit 2 of the DDC self -test register) did
not indicate it.
Seek completed, but the direction bit did not indicate out.
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