Help with SJ Research Nexus wiring

Hi All,

I’m looking for the wiring to the cables for the SJ Research Nexus Disc Sharer. I’ve checked all the documents I can find online in the usual spots like Chris Whytehead’s brilliant collection but none of the documents provide the wiring, although there are some clues.

Specifically I’m looking for:

- 4 pin mini DIN podule interface on the client to 9 pin D-sub connector on the SJ Research Nexus unit.
- 4 pin mini DIN podule interface on the client to 4 pin mini DIN connector on SJ Research Nexus Router.
- RJ45 on RiscPC/A7000 client to 9 pin D-sub connector on SJ Research Nexus Router.
- Any other potential wiring, A3010/A3020 network interface to 9 pin D-sub? (Don’t have the A30x0 interface yet!)

I have 1 cable that came with the Nexus unit but it’s 4 pin mini DIN plug on one side and 15 pin D-sub on the other, it doesn’t fit anything I have!

Ideally if I can get the 4 pin mini DIN & RJ45 to the 9 pin D-sub wiring it would be enough to get me going, I can probably work out the rest.

Any help greatly appreciated.

Thanks in advance,

Alan

Have you tried asking over on the StarDot forums, they are usually very knowledgeable on this sort of stuff! – https://stardot.org.uk/forums/

I hadn’t tried there, thanks. However, having searched their forums I see a post very similar to mine about the pin outs and unfortunately it went mostly unanswered there too.

Unfortunately it looks like I’m going to have to investigate myself and see if I can get it right without damaging anything.

Thanks

Just a quick update in case anyone else comes along looking for this…

With the help of Matthew Pye and Andrew Gordon I’ve managed to get a 4-pin mini DIN to 9-pin D-sub cable figured out, I just need to solder it up. I plan to document the whole thing and put it on my website, so I’ll post a link to it soon.

In the meantime…

Podule (4-pin mini DIN) → Nexus (9-pin D-sub)

Pin 1 (Tx+) – Pin 5 (Rx+)
Pin 2 (Rx+) – Pin 1 (Tx+)
Pin 3 (Tx-) – Pin 9 (Rx-)
Pin 4 (Rx-) – Pin 6 (Tx-)

The computer won’t yet boot from the Nexus disc but I can use command-line to browse it and also *filer_opendir to open it in WIMP environment.

Still struggling with re-partitioning the Nexus drive but I’ve managed to backup the original contents. The Nexus Utilities disc from Chris Whyteheads web pages is quite old so I’m not sure if this is the problem. Various Bad SWI errors in some Apps. I’ve got the Disc Sharer manual from his website so when I get a chance I’ll work my way through it to ensure I have everything as it should be. I believe the SCSI disc might be failing too and my attempts to replace it with a CF card to SCSI adaptor have been unsuccessful so far. Not sure if it’s compatibility with the adaptor or if it’s the Utilities disc/module versions at fault. Perhaps the microSD card is too large at 16GB, I should have a smaller one somewhere.

Still struggling with the RJ45 to 9-pin D-sub cable for the RiscPC/A7000 interface card, although Matthew has given me some clues for that but no luck as yet. Possibly incompatible versions with card/Nexus protocols. Not sure what’s compatible with what. Also, I have 2 of the RiscPC/A7000 Nexus cards and one has a small 8 pin chip missing from a socket. Both cards behave the same in my A7000.

Alan