NeXT Computer

Provenance

We acquired a NeXT Computer system from Cornell University, 2011 to be part of our Museum of 20th Century IT. It was used by Computer Graphics staff.

Description

It is the original, cube-shaped CPU, with a matching monitor and laser printer. The CPU also has an extra card called NeXT Dimension, allowing color graphics.

Refurbishing

Disassembly

Note, I usually keep track of where screws go by keeping the screws in threads which they threaded to attach whatever they attached.

Rear cover

There are four screws permanently attached to the rear plate that connect it to the body. A T15, or possibly the next size larger, or 3mm allen key can turn them. The fan is attached to the rear cover, so remove the cable between the power supply and the fan to set the rear cover aside.

Main boards

Both the motherboard and the NeXT Dimension board slide out from the backplane that connects all the boards. There are easy-to-remove cables between the drives and the motherboard that one should remove after sliding the motherboard out partway.

Center tower

The center tower holds the power supply and the drives. It is held to the body by two screws on the lower inside. Once those screws are removed, the whole tower slides out.

Drives

There are screws on either side of the center tower attaching the drives.

Cleaning

• Disassemble the computer.
• Vacuum the fan, the rear cover, and the inside of the case. Turn the case upside down and vacuum the vents.
• Vacuum the boards, but beware of static electricity that can build up on the nozzle, don't let it touch circuits.
• Vacuum the center tower, the vents on the power supply
• Vacuum the hard drive and optical drive.
• Wipe the inside of the case with a damp cloth.

Backup

While both systems are off, remove the NeXT HD and connect it via SCSI cables to another computer that has SCSI and also a UNIX type OS. I use a Beige G3. Use the dd command in the terminal or Apple's Disk Utility to make an image of the entire drive. Save it to CD or DVD, maybe twice. These computers are so rare it's not wise to depend on easy access to system files on the internet.

My specific experience

I removed the drive, and attached it to a power supply in a home made SCSI enclosure, and attached it to my Beige G3 via SCSI. I turned on the power supply in the enclosure, then my G3, starting in OS X 10.2. Apple System Profiler showed the hard drive (controller) and its SCSI ID, but not the size, and the drive did not spin at all. After turning everything off, I tried a jumper on the pin that makes the HD spin on power-up instead of waiting for the computer to send an instruction, and started again, but the drive LED then flashed 1Hz, which means error. I thought maybe the power supply was inadequate, so I used the power supply from a tower computer, with the jumper to make the HD spin on power up. Voilà!

I opened Terminal and entered the list command (ls /dev) to see what the system called the attached HD—disk1. I confirmed that disk0 was my internal hd and disk1 was the external by counting the partitions. Then I tested to see if I could copy a couple blocks from the attached HD:

dd count=2 if=/dev/disk1 of=testtwoblocks.img

It was a success, so I imaged the entire drive, which took 50 minutes, 230328 bytes per second:

dd if=/dev/disk1 of=NeXT-661.img

Battery

There is a 3V BR-2/3A lithium battery. Hopefully it hasn't leaked onto the motherboard. If so, remove salts with water and a toothbrush, and allow to dry completely. Removing the battery for a day or so erases the parameter memory (PRAM), useful if the computer has a hardware password that is forgotten.

Startup

Hold the p-key at startup to enter a boot menu. bsd -s will start the computer in single-user mode, which allows you to reset the passwords if you've forgotten them or don't know them:

passwd root

If you are asked for a hardware password, and you don't remember it, use the battery procedure.