PDP-11/04

There is a great page on the 11/04 right here: http://www.corestore.org/1104.htm

From the page:

The 11/04 was a mid/late-70s implementation of the Unibus pdp-11 architecture, and was essentially a replacement for the 11/05 & 11/10. It was the first pdp-11 to escape without a 'proper' lights & switches front panel, instead it had the glorified 'programmers console' as an option - a hex keypad and an LED display which showed address/data digitally. It came in two chassis, like the 11/05 & 11/10 - a half-height example, which had the entire Unibus backplane, power supply, front panel - basically the whole computer - sliding into an evil jamming finger-trapping metal sleeve - and a full-height example, basically the same BA11 box as used by the 11/35 and many many other DEC applications. It's very similar to its higher-spec twin, the 11/34.