[mchartmann]

A Challenge is accessed using a serial console (and ethernet, once IRIX is up and running). So you need a serial null modem cable. To make things harder, the port on the Challenge is RS232, but the pinout is not what's used on a PC, but something SGI specific and the connector on the system is a female rather than male one. You'll have to manufacture your own cable. The SGI pinout is documented here: https://techpubs.jurassic.nl/manuals/hdw...#id5436642

It won't hurt to start reading the user manual: https://techpubs.jurassic.nl/manuals/hdw...index.html
and at some point you'll probably need the service manual: http://www.futuretech.blinkenlights.nl/o...45-030.pdf

IP21 is an R8000 CPU board which is very cool if you're into retro-numerical computing but not better than a standard R4400 (IP19) at general purpose (integer) computing. The IP25 with 4x R10K CPUs is the most desirable.

You will need an MC3 and an IO4 board, and beware that the IO4 has both HVD (high voltage differential) and the more common SE SCSI on board. It can be configured using HVD (red) or SE (green) daughter cards. The SCSI box (where the drives go) has to be jumpered to match the IO4 configuration, and so must *all* the drive sleds. It is documented in the manual.

HVD is not LVD SCSI. In fact, if you connect a common SE or LVD SCSI disk to a HVD controller you will fry it, and possibly the controller as well. So if you build a system from a large pile of possibly unrelated parts you have to be very very careful. The default configuration for an Onyx/Chalenge is SCSI bus #0 in SE mode for CD-ROMs and tape drives, and SCSI bus #1 in HVD mode for the system disk and other disks. Unless you got a box of HVD disks with the system, I'd leave any HVD bits disconnected initially and put a regular SE ultra-wide or LVD disk on SCSI bus #0

There's much more information on Simon Pigot's old page (now gone) which I mirrored: https://www.jurassic.nl/mirrors/gisparks...gine2.html
Pay especially attention to https://www.jurassic.nl/mirrors/gisparks...slist.html when piecing together a system from a "box of parts" as certain board (like the R8000 IP19) require at least certain revisions of other components (like IO4 and MC3).

Last but not least: the R8000 cache chips are very susceptible to static electricity. Don't put that board on the carpet.

Thank you for the information. Its a lot more involved than my other SGI systems to get running but will be an interesting challenge, pun intended! The previous owner purchased this system from Epcot center in 1997 and has not been used since. I have the original SGI shipping label and bag for the new IP21. Its strange a server in a Onyx skin box though.