VAXstation 4000/90
miod > machineroom > manufacturers > Digital > VAXstation 4000/90
The VAXstation 4000/90, code named Cougar, is the successor to the VAXstation 4000/60, three times faster with its 72MHz NVAX processor with 256KB of L2 cache.
Since it shares the case, memory boards and 3D graphics options with the VAXstation 4000/60, one could consider it a simple processor replacement. Nothing could be further from the truth: the VAXstation 4000/90 is actually a brand new design, with the constraints of having to share form factor (and connector position) with the VAXstation 4000/60, which turned out to be quite challenging.
This machine was so successful that faster models were made: 83.3MHz VAXstation 4000/90A, and 100MHz VAXstation 4000/96.


(Click on the pictures to get larger resolution images)
The VAXstation 4000/90 uses the same `light' plastic case as the VAXstation 4000/60. The heaviest part inside is very likely the power supply on the left side.
The back of the machine is set up in a 3x3 grid, with two grid cells unused. The connectors are then:
Centronics SCSI-2 connector
Option connector: either a synchronous serial port, or a TURBOchannel slot Framebuffer connector: usually 3W3, two on dual-head cards, and sometimes with a VGA-compatible HD15 connector as well Power supply connectors
Remote keyboard and mouse cable (male DB15 connector), local mouse (mini-DIN) and keyboard (4P4C `RJ9') connectors Console or printer port (MMJ), modem or printer port (DE25 female RS232) Ethernet connector: either 10base5 (AUI) or 10base2 (BNC), with selector switch in-between

There are also connectors in the front of the system, once you flip the little door on the right side.
From left to right, they are:
The top of the case is kept in place by two tabs, which are easy to unlock. The bowels of the machine are quite crowded, although this one does not have a CD-ROM or tape drive. Note the internal devices brackets are made of plastic, too.
With the internal device trays removed, here is a better look at the motherboard. Note the daughter board on the right side.
The daughter board simply sports the front connectors, as well as the internal speaker; or, to follow the inscription on the board itself, the `lights and switches'. PV2 probably stands for PVax 2, which was the codename of the VAXstation 4000 VLC... although the VLC uses a different daughter board!

With all connectors and boards unplugged, the logic board slides and be extracted from the case, for a better look.
The connectors on the back of the motherboard are protected with a plastic cover. It will gently slide to reveal the naked motherboard.
Note the white power supply connector to the left: it is quite unusual, as the power supply is directly plugged to the motherboard.
The white connector in the middle is a frame buffer connector for VAXstation 4000/60 compatible graphics (SPXg or SPXgt). Below it, the black connector is a frame buffer connector for the native graphics (LCSPX). Over the right half of the white connector, the other black connector is the TURBOchannel option connector. The TURBOchannel option board connects there, and provides a TURBOchannel slot facing the option slot in the back of the enclosure.
On the right, over the processor which is easy to spot with its heatsink, the blue connector is the internal SCSI connector, and the black connector next to it accepts the synchronous serial port DSW21 option.
Unlike the VAXstation 4000/60 motherboard, there is no on-board memory; on the other hand, there are eight memory slots instead of six, with memory installed in sets of four memory boards.
Here is the processor without its heatsink. The clock source to its topleft corner runs at 286MHz, which yields a 71.5MHz processor speed (or the advertised 14 nanosecond clock cycle).

Here is a closer look at the LCSPX default frame buffer option.