HP 5061-6565 scsi loopback plug

Glen Slick glen.slick at gmail.com
Mon Jul 9 19:44:46 CDT 2018

On Mon, Jul 9, 2018 at 12:53 PM, Sven Schnelle via cctalk
<cctalk at classiccmp.org> wrote:
> I'm actually the one who asked Al about this test hood. It seems like
> it's a SCSI connector that connects the control lines to the data lines.
> I've added some code which emulates this in software and the ROM said
> 'test hood connected' after the HP98265A message, and waited 1 minute on
> boot. The 300 Test software also passed all checks. I'll verify that on
> real hardware, and post the connections.

See also this manual on hpmuseum.net :


Page 7-7 (Page 76 of the PDF), Table 7-2. Loopback Test Panel Configuration
DATA0 <--> I/O
DATA1 <--> C/D
DATA2 <--> MSG
DATA3 <--> REQ
DATA4 <--> ACK
DATA5 <--> ATN
DATA6 <--> SEL
DATA7 <--> BSY

No idea if the HP 1000 A-Series 12016A SCSI interface would use the
same loopback connections, but it wouldn't surprise me if they did.

(The earlier Feb 91 second edition version of the 12016-90001 manual
on Bitsavers does include the DDL Diagnostic Program Chapter 7, which
has the Table 7-2. Loopback Test Panel Configuration)

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