I looked after several 11/70's in late 80's to early 90's running RSX-11m. After any odd failures we would run IOX (I/O exerciser) that was on the RSX-11m boot disk.
The 9 pin connections are the standard 11/93 back panel ports for serial and a 25 pin serial console. The bottom right is DEQNA ethernet and the bottom left is SCSI. The system must have had or has a SCSI controller for the TZ30 tape drive in the front of the system
May be of interest to UK and beyond collectors,
https://www.ebay.co.uk/itm/115811150665
https://www.ebay.co.uk/itm/115811151888
I have no connection with the seller.
These usually come in a BA400 enclosure that may contain some DSSI disks and a TQK70 tape drive. Can you post some photos of the inside front so we can see what controllers it has and if it has any storage?
Teletech, slightly off topic but...in your second photo the keyboard is sitting on top of either a BA11-VA or a TU58 drive (possibly something else!) I have a BA11-VA based 11/02 running RT-11, I'd be interested to know what you are doing with yours, perhaps in a new thread. Thanks.
Are two terminators necessary/supported in the 11/05? I see two in the above photos. Perhaps as also previously suggested you cant try terminating at the end of the first backplane, that will eliminate the issue being in the other two backplanes.
Thanks g4ugm for the offer but I think I've made good progress. I dug out an NEC SCSI CD-ROM drive and while looking in the box I found a DEC RRD43, I've previously only tried known good working RRD42 drives from my VAXstations's.
I connected up the NEC drive and attempted to boot (boot...