PiDP-11

Today, the acrylic front panel I made came in. The colours are not right (for once, they are worse in real life than in the picture). And some other details did not come out as I want. For isntance, the LED windows are not shaded in red as they should be. Oh well, at least the colour bar at the bottom of this panel will help me colour-match against real PDP-11's soon.

This is a cropped version f the intended full panel. As long as I do not have a replica case, I'll let this cut-down-to-size version live in a PiDP-8 case.

The PCB should arrive on Monday, as well as deep-dark-red 700nm '70-style LEDs. Modern red leds are not quite right on the PDP-11 - thanks to Joerg for that tip! Things are moving now.

It took a while, but I'm still on track with the schedule I set myself at the end of last year (because, no schedule, no pressure, no progress). The prototype PCB should arrive in the coming two weeks, as well as the prototype acrylic panel, vector drawing below:

Especially the artwork of that acrylic panel took a ridiculous amount of time. I just get bogged down in useless perfectionism. Which is strange - because let's face it, this is not very complex artwork. But getting the placement and shapes exact is surprisingly hard.

This prototype will not look like the final version. For the moment, it will live in the case of the PiDP-8, which meant that I had to clip off about 1 cm from each side (see the thin red lines). But it allows me to check colours, electronics, etc - before plunging in and spend money on the replica plastic case. Molds are expensive, even for vacuforming.

Progress as usual is slow but reasonably steady. I just finished a PCB to test the design. And the custom 'PDP-11' style design is under review by the manufacturer in China (Daier, for those with a switch fetish).

The main thing for the coming month or two is producing a vacuformed plastic case. A rough design is ready but here I am definitely behind schedule as daily life wreaks havoc again on the things that really matter...

Progress so far:

- Arranged production of PDP-11 switches. Currently waiting for a revision to the CAD model of the switches, then it's a go.

- Schematics are done, as is the first draft of the PCB layout. The only thing left is to verify exact component placement by measurements on an original 11/70 in December

- Decided to produce the front panel bezel using vacuforming. First draft of CAD model, for the mold, is done but it needs more exact measurements to wrap up.

The project will only start for me when the PiDP-8's redesign (new switches) is done. In preparation though, I have started to get advice and check prices for vacuum-forming and injection molding at local manufacturers.

The front panel artwork is half done, with vectorising the PDP-11/70 logo especially taking a few autumn evenings...