BuildVAX - Builder of NetBSD


DEC Model Name
DEC Part Number
CPU Type

Memory (32MB)
      8 x 4MB
Disk Capacity
    2.1 GB
VAXStation 3100/M76
KA43 (7.6 VUPS)
Ethernet (ESA0)


SeaGate Barracuda

BuildVAX is a VAXStation 3100/M76. It is operating as a VAXServer (no monitor/keyboard/mouse attached) and was for a long time the machine I built the current copy of NetBSD on. At 7.6 VUPs it is a pretty fast machine, and as the manual is on-line, it is pretty easy to figure things out with it.

Like all of the 3100 series VAXen, the M76 is a desktop case (steel, very heavy) that comes apart by removing two screws in the back. The back of the system is shown below.

You can see the two screws on the left and right about 1/3 up the chassis. Perhaps one of the most annoying thing about the VAXStation 3100 series is the SCSI connector (shown top left of the back) which looks like a modern 68pin SCSI-III connector kind of but is in fact DEC's own design. It takes a special cable to go from that connector to external peripherals. 

Typically this would be connected to an expansion box which had a disk drive and often either a tape, a floppy, or CD-ROM for the removable media. The expansion box tape drive is the TZ30.

Inside there is room for three SCSI drives if they are "low profile" (see image below) The RZ series of SCSI drives have an L suffix when they can fit in to these boxes. There was a taller version of the BA42 chassis that was used with larger drives but that one gave way to this one.

The truly neat thing is that the internal SCSI bus (A)  is distinct from the external SCSI bus (B) so you can put three drives on the inside of this vax and then stack 7 more on the outside! BuildVAX normally runs with an expansion box that holds a TZ30 tape drive and an RZ26 disk. Internally it has a Seagate 2.1GB barracuda drive. On the tray there is an internal terminator that terminates this bus. 

When you remove the disk tray you can see the guts of the system that the next two pictures show (one with the SPX board installed and one without)


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Copyright (c) 2000, Chuck McManis, All Rights Reserved

NOTE: All images on this site are COPYRIGHT 2000, 2001 by Charles McManis, you may not use them without written permission from me! (Especially EBAY Auctions!) You may put a link to this site with a note that your system is "like" one of mine but you cannot use the images. Thank you.