And so, today, my Raspberry Pi arrived. Filling me with the kind of excitement and nervousness that I used to get when kits of bits would arrive for my beloved BBC Micro. Building up the sound sampler, grabbing my dad’s wire-wrap boards and sitting with the twiddley-tool (which no doubt has a proper name) and wire-wrapping my way to freedom. Or somesuch.
(Cut for geeking, talking about my dad and lots of images)
But there’s a melancholy side to this. Yesterday I downloaded Fritzing and spent the evening and some of today creating this*:
Which is one of the two boards required to make the USB Serial Nixie display I’ve been toying with making. Toying with it in that dangerous way where I get really quite excited and then order things. I’m a bad Kate. Anyhow, playing with the PCB routing** has made me realise quite how much my dad must have enjoyed this. I know he enjoyed problem solving, and this, this is just one massive sliding block puzzle, only the sliding blocks are attached by magic string…
Anyhow, as midnight rolled around yesterday it became apparent that I quite enjoyed it, then the hour I spent on it tweaking it this morning (not even degenerating into swearing when Fritzing crashed…lots of times in a row***) flew by. And when I finally got components arranged to a level where it actually could, conceivably, be made… Oh, and discovering that I could actually get them to make it, so I could have a nice silkscreened board sent to me ready for me to make up? Oh, the excitement.
But tinged with melancholy. My dad would have loved this stuff. He would have been totally wired about the Pi. It’s an ARM. He loved ARM, I love ARM because RISC is quite simply beautiful. He always taught me that good engineering is beautiful; if you can’t make it beautiful, then it’s the wrong solution (see the Morris Minor’s petrol pump for an example of what starts as a beautifully simple idea, but is clearly wrong because of the amount of hodging required to make the damn thing work). And the ARM has a really simple beauty. And Fritzing (and similar much more advanced tools) and 3D printing? He’d have been in maker-heaven. He had an infectious excitement about this stuff which is hard wired into my DNA. Lurking at the back of my consciousness, waiting to find something to latch on to. I’ve wanted to have a 3D printer for ages, I’ve wanted to toy with the Pi since I heard about it being developed… And now I can, I’m thrilled, but also incredibly sad that I can’t share it with him.
But thinking about him and his work made me remember that kicking around upstairs I have some ribbon cable. Not the flat grey crap you get now, nor even the pretty stripy cable you got in my youth:
No, this is proper ribbon cable.
It looks almost brown in the photo, but it’s actually purple and yellow. And awesome. Obviously, for most modern uses it’s completely impractical. It would completely screw timing for the tight tolerances most modern kit requires and would also be a nightmare for machines to wire up – because wire 1 at one end could be wire 33 at the other, or 4 or 7… or anything. And that varies depending on what point you cut it. And how tightly the machine’s twisted any particular section of it together. Which is, I guess, why my dad had left it unused.
But it is cool. It’s cool in a way which modern cable isn’t.
And all I’m planning to drive with it is an LCD. A serial LCD. And if you can drive it using multiple separate fly leads, I reckon I should (should) be able to get away with driving it using this ribbon cable. So later today I shall solder some of that fine cable to my LCD. And then tomorrow I need to pick up a connector to go onto the Pi’s GPIO. And away, as they say, we shall go.
Whilst I was up fishing the Pi out of it’s box**** and digging the cable out from the box in which they lurk, I took a moment to snap a few shots of the new and shiny Pi next to the first processor my dad designed (I believe that’s true). This is a 1 MHz processor from the late 60s, I think. Possibly a processor for the Modular One, although I’m not sure (it’s marked 8650). Now I know my dad designed the floating point maths unit for it, I’m not sure about the processor itself. I actually have a wire-wrapped prototype of the FPU with my dad’s cheerful green ink on it proclaiming ‘Floating Point Unit’. This board has a monitor which goes with it (in the photos) which has my dad’s writing on it, so I suspect the whole thing was his design, or he was strongly involved. He appears to have been at CTL right from the start, which probably explains why he was allowed to bring his kid in to sit and play games on the mini-computers there*****.
Anyhow, so here’s to British computing:
And yes, I need to take these around to John’s and get some proper photos of them.
* I thought I’d start simple, y’know, with a double layer, twin board, 190 volt device. Obviously.
** It’s still not right, it’s close, but would end up with a link wire, and I can’t have that. Also I didn’t spend enough time checking the schematic before I made it, so I’m a bit paranoid that it might have some massive Nixie-or-USB-frying bug. Gonna redo it now I know how to use the software.
*** While it shouldn’t have crashed, the fact I had the crystal sitting on top of a resistor may well have had something to do with it. Yes, yes, I should have run the little checky thing first, but I didn’t err…discover that… until later :)
**** Pi box… Heh. Raspberry Pi is such a fun name.
***** Mmm, formative: