DIY HP-MSIB Cable

HP-MSIB cables, original or third-party, are now difficult to find and frequently for more money than the equipment to which they will be connected. It seems HP used special controlled-impedance cables for their originals, but it turns that for reasonable-length runs, simple 50-pin twisted pair SCSI cable works just fine. This is how I built mines.

HP-MSIB cables have a cheap, simple, ordinary, 37-pin D-Sub connectors, male at one end and female at the other. Wiring is simply pin-to-pin for all pins but three, pin 19 which goes to chassis ground and pins 16 & 35, which are jumpered together at the connector, with no associated cable pair. Signals on the pins are layed out so it is easier to wire the pairs, which are 1/20, 2/21, ..., 17/36, 18/37. Cable shield goes to connector shield at each end. MSIB output at the instrument requires a FEMALE connector cable end, while MSIB input at the instrument requires a MALE connector cable end.

Here is the detail of the FEMALE connector, to be connected to a MSIB output: