I keep meaning to post this and I keep forgetting...
Nexus cable types
MiniDIN pinouts
Looking into the female connector on a Socket Box or Podule, pins are numbered from 3 o'clock, 1-3-4-2.
1: TX+
2: RX+
3: TX-
4: RX-
4-pin IDT pinout
This is a 4-pin IDT connector compatible with the 0.156in pitch 4-pin Molex KK. The IDT is no longer available but the Molex is a reasonable substitute.
With pins pointing up: order is 1-2-3-4.
1: RX+
2: RX-
3: TX-
4: TX+
If you get RX and TX swapped you can in theory flip the connector upside down...
9-way D-sub pinouts
Seen on Nexus disk Sharers. DE9 female on the "client end", DE9 male on the "server end".
1: TX+ out
2: 5V input
3: 0V
4: 5V output
5: RX+ in
6: TX- out
7: Not 10 Grant
8: Not 10 Req
9: RX- in
To force 10MHz mode (for long cable runs) connect pins 3 and 7 on the client end, and 3 and 8 on the server end.
I don't think any "clients" had these connectors, but they were used on the ends of in-wall runs.
15-way D-sub
Seen on A3020/A4000 interfaces.
6: TX+ out
8: RX- in
14: TX- out
15: RX+ in
Other pins unknown
RJ45
Seen on RISC PC NICs
Looking into the socket on the Podule (or at the plug with pins facing away), pins are numbered 1 to 8 from left to right.
4: TX+
5: TX-
7: RX+
8: RX-
Because this uses the pairs 10/100 Ethernet doesn't use, it might be possibly to put 10/100 and Nexus on the same cable (maybe). Doesn't sound like a good idea to me, though.
I've got some scanned Cumana Nexus documentation someone sent me which I need to sit and read through... but from what I recall it doesn't include pinouts.
Nexus cable types
- Station cables (from socket box or sharer to client): Cross-over. TX+ to RX+, TX- to RX-, and vice versa.
- Trunking cables (from disk sharer to cable in trunking): Straight.
- MiniDIN to DE9: From a Disk Sharer to a Socket Box.
- MiniDIN to MiniDIN: From a Client Station (Podule) to a Socket Box.
- MiniDIN to DA15: From a Socket Box to an A3020 or A4000 with a NIC-slot Nexus network card.
MiniDIN pinouts
Looking into the female connector on a Socket Box or Podule, pins are numbered from 3 o'clock, 1-3-4-2.
1: TX+
2: RX+
3: TX-
4: RX-
4-pin IDT pinout
This is a 4-pin IDT connector compatible with the 0.156in pitch 4-pin Molex KK. The IDT is no longer available but the Molex is a reasonable substitute.
With pins pointing up: order is 1-2-3-4.
1: RX+
2: RX-
3: TX-
4: TX+
If you get RX and TX swapped you can in theory flip the connector upside down...
9-way D-sub pinouts
Seen on Nexus disk Sharers. DE9 female on the "client end", DE9 male on the "server end".
1: TX+ out
2: 5V input
3: 0V
4: 5V output
5: RX+ in
6: TX- out
7: Not 10 Grant
8: Not 10 Req
9: RX- in
To force 10MHz mode (for long cable runs) connect pins 3 and 7 on the client end, and 3 and 8 on the server end.
I don't think any "clients" had these connectors, but they were used on the ends of in-wall runs.
15-way D-sub
Seen on A3020/A4000 interfaces.
6: TX+ out
8: RX- in
14: TX- out
15: RX+ in
Other pins unknown
RJ45
Seen on RISC PC NICs
Looking into the socket on the Podule (or at the plug with pins facing away), pins are numbered 1 to 8 from left to right.
4: TX+
5: TX-
7: RX+
8: RX-
Because this uses the pairs 10/100 Ethernet doesn't use, it might be possibly to put 10/100 and Nexus on the same cable (maybe). Doesn't sound like a good idea to me, though.
I've got some scanned Cumana Nexus documentation someone sent me which I need to sit and read through... but from what I recall it doesn't include pinouts.
Statistics: Posted by philpem — Wed Feb 04, 2026 10:07 pm