My Machines

GALLERY: My Collection

PDP-8/M Rebuild – Job checklist

To ensure nothing gets missed, I use a checklist of tasks to be done when rebuilding machines. This is the the list for my 8/M rebuild:
Completed

Perform a general appraisal of machine
Photograph machine in detail
Remove console and cards
Remove power supply
Remove wiring looms and any other remaining items attached to chassis
Remove backplane
Clean and sand chassis
Spray chassis to… »

PDP-8/M Rebuild – part 4 – Reassembly and first power up

Having reinstalled the power supply into the chassis, the console was put back into slot 1 and carefully reassembled.
The minimum board set was then installed consisting of:

Slot2: M8330 KK8-E timings
Slot3: M8300 KK8-E major registers
Slot4: M8310 KK8-E major register control
Slot 20: M8320 KK8-E bus loads

The machine was then powered on and LEDs on the console sprung… »

PDP-8/M Rebuild – part 3 – The Power Supply

The PDP-8/M uses a H740 switch mode power supply that provides +15V @ 1A, +5V @ 17A, -15V @ 5A together with LTC-L, PWR OK L, PWK OK EN, AC LO L, and DC LO L signals (it should be noted that not all of these signals are used within the PDP-8M). This power supply… »

PDP-8/M Rebuild – part 2 – Chassis repaint

The chassis had all internal components removed (after carefully photographing everything to aid in reassembly) before being sanded down. Any areas of rust were sanded back to bare metal.
Unfortunately I could not persuade the build label to come off of the chassis cleanly so this had to be sacraficed. Before I removed it I carefully… »

Adventures in LSI land

Over the last couple of weeks I have spent most of my available ‘PDP’ time bringing rebuilding as many of my QBUS machines as I can.
This has largely been a painless process, largely aided by the set of LSI-11 maintenance manuals I recently got hold of. Compared with their large UNIBUS brothers, the QBUS family… »

PDP-8/M Rebuild – part 1 – Initial Inspection

I’ve finally decided to bite the bullet and start the rebuilt of one of my OMNIBUS PDP-8s. I decided to start with the more challenging of the two using the theory that by tackling the worst I would be much better prepared for a simple rebuild of better condition machine.
An appraisel of the machine
Before commencing,… »

Latest Arrivals

A few more new machines arrived this week and some might fine additions they were two:

PDP-11/70 in H960, alas no memory at present
PDP-11/70 in a tallboy corporate cabinet
PDP-8/E, OEM branded
Dec Professional 380
2 x Decmate IIIs
TSZ07 SCSI Mag tape drive
PDP-11/05 (5.25″ version), missing its front graphics (I guess swiped by a trophy hunter)

[Gallery not… »

uPDP-11/83 rebuild begins

For some light relief from rebuilding the more complicated UNIBUS machines, I decided to take a break and tackle something a bit simpler, a QBUS based uPDP-11. I have a few uPDP (BA-23) chassis lying around so I picked one of these as the basis for the machine.
As the machine had only left service a… »

Inventory: QBUS Cards

I have the following spare QBUS cards in my collection:

M3104 (10 off) – DHV11
M3106 (4 off) – DZQ11-M 4 line serial
M3107 -(6 off) – DHQ11-M 8 line serial

M7193 (2 off) – DRQ11-CA DMA interface, 16-bit
M7164 – KDA50 – Qbus SDI disk adapter, Q22 (1 of 2)
M7165 – KDA50 – Qbus SDI disk adapter, Q22 (2… »