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• Done! (Mostly)

  Oscarv • 05/02/2023 at 22:19 • 1 comment

  Today the final prototype went through evaluation with the injection mold maker. There are some imperfections in this CNC-cut prototype, but they will be taken care of in the mold. I can't wait for the first samples to come back from the manufacturer. Alas, that will take 8 weeks or so. 

  Isn't she pretty? And just wait what this machine can do running ITS!

  So - today was a good day!

• An injection mold proved inevitable

  Oscarv • 04/21/2023 at 23:16 • 0 comments

  It has been nearly three years since my last update here! But in the mean time, the software is pretty much done (famous last words), we've been playing a lot with ITS and all its graphics fun (multi-player mazewar, spacewar, it really is amazing how much software there is to play with on a PDP-10. See here)
  

  Although I promised myself never, ever, to do an injection mold again, that proved to be inevitable. So here is the CNC-cut prototype that will go into production in the coming weeks:

  Two molds, actually. A bottom, and a top part. To get all of the curves of the original properly made, I ended up needing professional help. The risk of cutting expensive injection molds with mistakes was too high, and 3D modeling the slight oddities of the 1966 original was also a bit beyond my skills.
  

  New PCBs have been spun to fit precisely in this case:

  126 LEDs, and...

  
  

  ... 74 switches. This is a big beast!

  To be continued soon. Or join the PiDP-10 Google Group if you want to follow progress more closely.

• It blinks!

  Oscarv • 03/05/2020 at 18:17 • 0 comments

  Progress!

  The PCBs are soldered up (minus the switches, but they do work) and the PiDP-10 started to do its first blinkies. Admittedly, it still thinks it is a PDP-8 with a novel panel layout (I used modified pidp8i software for testing), but blinkies nevertheless.

  As it turns out, the new-to-me MCP23017 GPIO chip is really easy to control. Just a few lines of code; and the speed of the I2C bus is OK for this application. That was one concern: 24 bits of I/O a few hundred times per second, with enough time in-between to light up the LEDs in the multiplexing routine. I had to up the I2C clock on the Pi, but that was easy too. Everything is easy with a Raspberry Pi. Sometimes.
  

  Hopefully, the switch panel cover gets through Customs soon. Then, I have a complete demo machine :)

  Now on to modifying Richard Cornwell's KA10 simulator, so the machine can start to feel its 36 bits of simulated power! Oh, and soldering 72 switches. A chore I'd better get used to.

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