SBUS 32MB Expansion Board (p/n 501-1823) in Sun IPX

[swynn97]

I'm trying to get an SBUS 32MB expansion board working in a Sun Sparcstation IPX. The issue I'm having is that I don't have the flex cable 530-1814 to connect from the board to the motherboard SAX connector. I tried making a 1-1 cable, but once installed, the system wouldn't startup - not even to open boot, so obviously the wiring was not correct.

I have the pinout for the SAX connector on the motherboard, but I don't have the same pinout on the SBUS card, nor any idea of the correct wiring. Can anyone help here with a wiring diagram, hi-rez photos of the 530-1814 cable, any other help?

thanks,

Simon

 

[swynn97]

I've answered this myself by actually finding a genuine 530-1814 cable - I'll post the wiring soon, but basically it's a 1-1 mapping with a 180 degree twist.

What hadn't occurred to me was that the 501-1823 isn't actually designed to fit in the IPX (duh - that's why it's called a Sparcstation 2 card...). The IPX is essentially the same machine as the SS2, and I installed the card just fine. Booted to an impressive 128MB of RAM with the addition of the 501-1824 card. Then I tried to close the case, but the PSU case hits the SAX connector on the side of the card. The DATARAM cards have this connector positioned further back, so they fit inside the IPX case just fine.

Given that the card works just fine electrically, I proceeded to cut off the connector housing, trim the pins, and hard-wire a cable onto the pins. This gave enough clearance for the PSU. Note, you really need some sharp wire cutters and small needle-nose pliers to remove the connector housing, and you need to be super careful. Anyhow, this hack works just fine! Photos attached.

Simon

 

[swynn97]

If you want to make a clone of the 530-1814 cable, just wire two 8-pin 0.1 inch pcb mount headers with about 9cm of thin wire as follows, see the photo of the real cable - basically pin 1 -> pin 1 etc. A 1-1 mapping, except that in reality, the cable is rotated 180 degrees due to the orientation of the board connectors.

 

[pkhoury]

I don't suppose you'd have any higher resolution photos of what your IPX's systemboard looks like with the modifications you made?