Reg Picture puzzler

Re: Reg Picture puzzler

From an ex-DECcie and ex-EE (Soton Uni)...

1. An IBM 704 logic module from the mid-50s – difficult to know which actual module this is but it looks like a set of ECC82s which are in a multiplier.

2. Packard Bell 250 from early 1960s

3. PDP 12 from late 1960s – worked on those

4. PDP 8/E from the 70s – still got a manual from that!

5. DEC/Digital PDP-10, model KL-10 also known as a DECsystem 10 from mid-to-late 70s complete with its power controller

6. a few bits of core memory – used to be made by hand in the far east – the first case of off-shoring technology?

Looking at this, it looks like it comes from a Honeywell DP-516 or one of its earlier siblings – a 316? – I worked on one of these in the electronics dept at Southampton Uni in about 1976 – it also had a “drum memory” and a fantastic high speed optical paper tape reader…

They also had a Modcomp MAX4 there which replace the DP516 eventually.

7. A diode gate array – they look like IN914s or IN4148s, but could be pretty much any small signal silicon diode – diodes were (and still are) used for “wired-OR” logic.

8. This is definitely DEC again – probably a DECsystem 10, maybe a KL-10 – the colours used give it away - DEC even made their wire-wrap match the company colours…

Out of interest, to try to make some of their cabinets less boring, for some of the PDP-11 range they introduced “environmental side panels” that were garishly horrible in what can only be described as a 1970’s way…

9. We’re back to Honeywell here – when this system and the Modcomp mentioned in #6 were patched, engineers used to come in and re-do bit of the wire wrap. Them was the days… Still got my own wire-wrap tool and some spools of that nice Teflon-coated, silver plated, fine wire that was used.

10. Back to DEC PDP-8 again – These are “Flip Chips” all dating from the late ‘60s to early ‘70s - The “M” in the numbering stood for “Magenta”! There’s a surprise…M310 is a delay line (timing module), M360 is a variable delay line (another type of timing module), M113 & M115 are NAND gates, M216 is a 6 unit flip-flop (bistable), M617 is a set of 6 NOR gates. The timing modules were used to get round race-hazards in gate time – an early kludge basically. Flip chips were eventually discontinued as they were unreliable for a number of reasons, mainly due to the edge connectors – we were always having to reseat them.

11. This is obviously from a drum line printer from an old mainframe. It looks like the ones used in the ICL 1904T series units, i.e. mid ‘70s again but can’t be sure…

Still got some of this sort of just in my workshop (aka shed)...