Understanding DECsystem 5100 Self Test Failure

Robert Jarratt robert.jarratt at ntlworld.com
Sun Jan 4 15:31:05 CST 2015

> -----Original Message-----
> From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of emanuel
> stiebler
> Sent: 04 January 2015 20:04
> To: General at classiccmp.org; Discussion at classiccmp.org:On-Topic and Off-
> Topic Posts
> Subject: Re: Understanding DECsystem 5100 Self Test Failure
> On 2015-01-04 12:46, Robert Jarratt wrote:
> > When I power up my DECsystem 5100 I get the output shown at the end of
> > this email. I thought this was to do with the DS1287 chip as it seems
> > be an NVRAM battery error (perhaps). Since I know these devices fail I
> > took out the DS1287, put in a socket and then bought a replacement
> > DS12887A. But I still get the same problem. It could be that I bought
> > a bad replacement, or that I have done some damage in my desoldering
> > of the original, or it could be that the error is something completely
> > different. In fact the Maintenance Manual suggests test 9 is to do
> > with the DZ, and I can't find what test 4 relates to.
> test 4 is RTC test

Hmmm, that seems to pass OK if I do this:

>> test -v 0x4

-004-03 rtc tsts
-004-04 wrt nv ram w/ aa
-004-04 chk nv ram w/ aa
-004-04 wrt nv ram w/ 55
-004-04 chk nv ram w/ 55
-004-05 wrt nv ram w/ inc pat
-004-05 chk nv ram w/ pat
-004-06 wrt rtc reg w/ inc pat
-004-06 chk rtc reg w/ pat
-004-07 set time - enb uie int
-004-08 chk periodic int

The  test numbers in the power-up sequence don't match the numbers in the
extended list of tests where the test numbers are in hex (test 10 in the
power up is test 0x4 - RTC).

Having discovered the test -v options I got a bit more detail from test -v

-005-05 dz ln 01 int rx/tx lpback tst
?45a nv ba?45a nv bat
                     -005-05 dz ln 02 int rx/tx lpback tst
?45a nv ba?45a nv bat
                     -005-05 dz ln 03 int rx/tx lpback tst
?45a nv ba?45a nv bat
-006-03 sii tsts
-006-04 sii buf ram tst
-006-05 sii trgt tst
-006-06 sii initiator tst
-007-01 lance tsts
-007-03 lance csr tst
-007-04 lance intrnl lb tst
-007-06 lance crc err detect tst
-007-07 lance promiscuous mode rx tst
-007-08 lance coll detect tst
-007-09 lance multicast rx tst
-007-0a lance irq tst
-008-03 eeprom tst
-008-03 chk pats
-008-03 chksum tst
05..04..?45a nv bat


It suggests the 09 test is a loopback problem, and that would be OK as I
don't have a loopback connector installed, but looking again, the test is an
internal loopback test. But it does not help at all on the 04 failure....



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