OscarvI finally got round to making a Youtube movie of the PiDP in action: http://youtu.be/5hyUActgT2E
Some points to note though:
- I still have to verify all the LEDs respond exactly as they do in the real 8/I - I believe so but the real test is at the VCF East!
- You'll note that those switches that are momentary toggle switches in the original are still 'flick on/flick off' in this prototype. I'm planning to put some springs in these switches to make them momentary - it's not hard to do. But to be honest, you get used to this so quickly it's not very high priority. The front panel software converts a on/off toggle into a momentary signal anyway.
- Also, the STOP switch is meant to be upside down from all the other switches (off = down). I let it be inversed - off = up - for the moment, it's a setting in the code but I prefer it this way myself.
- This particular PiDP uses a Raspberry Model B+, so it has a slot in its side to let out all the connectors. But using a Model A+ is both cheaper and more elegant. You can establish a terminal session through ssh on the network, or hook up an old serial terminal. The advantage of ssh, of course, is that you can hook up multiple terminals that way. Although I still have to test that!
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Re the screen: I rebuilt a vectorised drawing from photos. The exact process is on the blog site, but putting a photo straight on acrylic would not give acceptable results. The reproduction is pretty much pixel-exact to the original. With the exception of having lowered the bottom brown/white bar a few mm - and having left off the leftmost part of the original PDP-8/I, where there's no controls.
Re the Data Break handling: that's *exactly* the right question. These 3 leds are the only ones where I'm sure the leds do not blink as intended. I'll need some input from the real PDP-8's at the Vintage Computer Festival for handling Data Break correctly. The other light I would not vouch for is Defer, I think it lights up too long at the moment. But I have to see the Real Thing in action to judge that properly...
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Do you have the high rez image for the acrylic screen? If not how did you build it?
Also, does your emulator use the 3 part break light for disk access? Just curious.
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