PDP-11/40 with TU56 dual DECtape drive.
|Manufacturer:||Digital Equipment Corporation|
|Word Size:||16 bit|
|Physical Address Size:||18 bit|
|Virtual Address Size:||16 bit|
The PDP-11/40, introduced in 1973, using the KD11-A CPU, was the second machine to support 18-bit memory addressing on the PDP-11 platform, after the PDP-11/45 (albeit with a subset of the PDP-11 Memory Management architecture).
The 11/40 was also a primary platform for early UNIX.
The OEM version of the -11/40 is the PDP-11/35; the machines are completely identical, except for the printing on the front panel.
A special -11/40 with a blue front panel was used as the front-end for the KL-10 in DECSystem-10s and DECSystem-20s - though the 11/40 panel was hidden behind a cabinet door on the -20.
The /40 was introduced in January, 1973. It was a higher performance version of the /20, with a microcoded multi-board CPU. 18-bit MMU (-> max. 128 kw memory), FPU and EIS/FIS (extended/floating point instruction set) were available options.
There was a 'graphical' workstation model of the /40, marketed as the GT44. Many /40s were used in DECsystem-10's (KL10's, to be exact), as the frontend/IO-processor. These were painted differently, the panel looks awsome in blue too. (no, it's not just the frontpanel, that I like about the -11...)
On the picture to the left we can see two RK05's (disk pack drives) and two TU60 (DECcasette) units. On this picture we can see a close-up at the frontpanel (with bootdevice-selector panel) and the paper-tape puncher/reader.
OS's at this point: DOS/BATCH, RSX11, RT-11, RSTS.
Trivia: The 11/40 was one of the most often "cloned" machine. the soviet/tscech/polish SM-4 (CM-4), the hungarian TPA-1140 are all copies of this computer.
|v • d • e PDP-11 Computers and Peripherals|
| Unibus PDP-11s - PDP-11/20 • PDP-11/15 • PDP-11/35 • PDP-11/40 • PDP-11/45 • PDP-11/50 • PDP-11/55 • PDP-11/70 • PDP-11/05 • PDP-11/10 • PDP-11/34 • PDP-11/04 • PDP-11/44 • PDP-11/60 • PDP-11/24 • PDP-11/84 • PDP-11/94
Clones: CM 1420