The Jim Austin Computer Collection

Digital VAX 11/780


 

This is a classic machine. It was the successor to the Digital PDP 11 series. By adding Virtual Address eXtension Dec gave it a larger address range.

This machine came from a Dec dealer in Scotland, in Oct 2007. It has a complete processor, but has a missing boot up system (PDP 11/03 and floppy) and missing power supplies.

It does have the extension cabinet with a tape drive and a 470Mb disk.

Its probably made round about 23/7/1981, as that's a number on the expansion cabinet.

I will, probably, try to find the missing parts.

Pictures of how to get a vax that was 'dropped' by the lorry in the drive!

As it arrived, wrapped

Showing the broken pallet. Sides removed ready to shift

Here we go!

Got it off!

In the shed

Pictures of the cards

Pictures of the backplane

It has the following cards installed, starting from the right

RH780 subsystem

No M Card number  
1 8275  
2 8276  
3 8277  
4 8278  
5 7013 Blanking
6 7014 Blanking

RH780 subsystem

No M Card number  
1 8275  
2 8276  
3 8277  
4 8278  
5 7013 Blanking
6 7014 Blanking

Memory subsystem

No M card number Use
1 7014 Blanking plate
2 NS789 1 Mb Memory
3 NS789 1 Mb Memory
4 NS789 1 Mb Memory
5 NS789 1 Mb Memory
6 NS789 1 Mb Memory
7 NS789 1 Mb Memory
8 8373
9 8373
10 8375
11 8376
12 8375
13 8373
14 8373
15 NS789 1 Mb Memory
16 NS789 1 Mb Memory
17 NS789 1 Mb Memory
18 NS789 1 Mb Memory
19 NS789 1 Mb Memory
20 NS789 1 Mb Memory

DW780 subsystem

No M Card number  
1 6270  
2 6271  
3 6272  
4 6273  
5 7014 Blanking
6 7014 Blanking

KA780 subsystem

No M card number  
1 8237 Main processor cards
2 8218
3 8219
4 8220
5 8221
6 8222
7 8223
8 8224
9 8225
10 8226
11 8227
12 8228
13 2229
14 2230
15 8231
16 8232
17 blank  
18 7014  
19 blank  
20 8230  
21 blank  
22 8234  
23 8235  
24 7014 blanking
25 7014 blanking
26 7014 blanking  - these are slots for a floating point unit
27 7014 blanking
28 7014 blanking
29 8236  

Expansion cabinet

  1. CDC BY4A5-F 1600 BPI tape drive
  2. System international 470Mb disk

Card cage with:

  1. Emulex tape controller

  2. M7819

  3. M9014