Divemaster does carry the cables, but of course he's got to pay to get them, and then make a profit, so even though his shipping is very reasonable, it ends up costing more for the 2 I need (one Opti-Pack, one IPac) to get them from him than to get them from Ultimarc straight.
For others considering buying an IPac or OptiPac used: Be sure to consider cabling in your purchase decision. I bought from a person who didn't have the cables I needed, so now I'm having to cope. If I bought the cables from Ultimarc now, I'd end up paying MORE than if I'd just bought the whole mess from them originally. Buy making them myself from junk I already have, I'm keeping the cost down, but as a warning: Consider cables and their cost!
I've worked out the pinout for the IPac USB cable myself.
Connector diagrams are found at
http://pinouts.ru/connector/6_pin_mini-DIN_male_PS2_STYLE_connector.shtml and
http://pinouts.ru/Slots/USB_pinout.shtml .
I will describe the wiring between a MALE PS/2 connector (cut one off a dead keyboard or mouse) and a MALE USB A connector, using the pinouts given at the sites above.
USB Pin 1 (VCC) PS/2 Pin 4
USB Pin 2 (D-) PS/2 Pin 1
USB Pin 3 (D+) PS/2 Pin 5
USB Pin 4 (GND) PS/2 Pin 3
If you go the Cypress web site you can download a data sheet for the CPU used on the IPAC and OptiPac. On my IPac (40 pin CY7C63413C-PXC), Pin 1 is D+, Pin 2 is D-, Pin 20 is VSS (GND) and Pin 40 is VCC. After building the cable, be sure to plug it into the IPAC and use a meter to test continuity from each pin of the USB all the way down to the CPU. That way, you know you've got it right.
When testing, be sure to use a hub - not your computer. That way, in the unlikely event of something going horribly wrong, you won't blow up anything important.
If you are stupid or incompetent, please don't try to do this yourself.
I'll post again later after I build the OptiPac cable.