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BMOW Road Trip

I took the BMOW 1 hardware on the road this week. A few of the people I work with have been polite enough to feign interest in the project, and I’d repeatedly promised to bring it to work for a demo when it was ready. On Monday I lugged the whole setup to the office, and left it there for two days, showing it off to whomever came by and asked about it. I wish I’d taken some photos. It turned out to be a great dry run of what I’m likely to encounter at the Maker Faire next month, and I learned some helpful things about the demo and myself in the process.

  1. From an audience of very technical people, it basically broke into two groups. Most asked one or two general questions, and left in less than a minute. A few stayed for 15 minutes or more. Some of this was detailed BMOW questions, and some was stories of their own about hardware “back in the good old days”.
  2. I had trouble summarizing what the project was in a couple of sentences, and really need to work on this. Many people didn’t seem to grasp what it meant to build a custom CPU, although they got the general idea.
  3. I found that I actually got bored of talking about the machine after the fifth or sixth repeat of the same little talk. That doesn’t bode well for the 18 hours of the Maker Faire. It actually surprised me– I thought I’d never get tired of talking about my projects.
  4. Everyone wanted to see the wiry mess, which is unsurprising given the project’s name. Sadly, all the wires are hidden on the underside of the board when it’s mounted in its case. For the Maker Faire, I’ll definitely have plenty of photos on hand of the wiring side, and a sample wire-wrap board. I wish I could think of a safe and easy way to let people see the wire side of the BMOW main board when it’s on display.
  5. Quite a few people said they’d expected it to be bigger. I’m not sure how to respond to that.
  6. I may need to add some more built-in demos. There are 12, but they basically break down to listen to some music, look at a picture, play chess, or run BASIC. Nobody got further in BASIC than: 10 PRINT “HELLO”, 20 GOTO 10.
  7. Stability was pretty good. Over two days, constantly running in a demo loop, it only crashed a couple of times. There were a few very bizarre bugs that disappeared after a reset, though, like the “C” key stopping working.
  8. A few people joked about “accidentally” spilling coffee onto the board. With a few thousand people at the Maker Faire, somebody probably will spill something on it. I’m still unsure what the best way of protecting it is. I’ll probably need some kind of transparent protective cover.

In another month, I’ll go through the same drill again at the Faire, but with better props and a much larger audience.

Read 8 comments and join the conversation 

8 Comments so far

  1. John Honniball - April 30th, 2009 1:37 am

    I found when showing the Compukit UK101s at the UK Maker Faire, that by the end of the two days I had a much better idea of how to describe the machine than when I started. People came along and asked questions, made comparisons with other machines and generally came up with things I hadn’t thought of. So it’s a really good idea to do a small-scale demo like this before the Faire! Fortunately the BBC came along to interview me at the very end of the show — the interview definitely benefitted from the experience of the previous two days!

  2. Tomas - May 27th, 2009 10:02 pm

    Wow! Good show!
    Your project hits exactly were I used to ‘live’.

    In tha early ’80s I built a wire-wrap Z8-BASIC computer with a VOTRAX chip as an X10 home compuer contoller. Great fun and it worked, too!

    That was on the heels od hand-assemby coding of an Altair 8800 box…

    Hats off to your exploit. It’s so easy to buy instead of build now.


  3. Craig - May 28th, 2009 5:30 am

    First, congratulations on your project. I really like what you’ve done and appreciate it. Your comment about “what it meant to build a custom CPU” is right on the money. With a project like this, it’s important to step back and see if from the audience’s perspective. What I’d do is set up an old PC with the motherboard exposed, hilight the CPU on the motherboard, and show people that *that’s* what you’ve built. I expect many in the audience are probably thinking you’ve built a motherboard or PC, not an actual processor. If you wanted to take this project further, you might consider developing a 4-bit processor built from TTL as an educational kit, perhaps based off the Motorola architecture, as you’ve done here. There was a 4-bit Intel 4004 processor, but I always thought the Motorola architecures were more intuitive and regular. I think most kids who graduate with computer science or computer engineering degrees these days really don’t understand what happens down there on the bare metal, and I think it would be a great thing if they *all* had to build a CPU and program it before they graduated.

  4. Hamilton - May 28th, 2009 9:57 am

    What a great project! Definitely takes me back to the “bad ol’ days” 😉 Too bad you didn’t realize the asthetics of the wiring sooner. You could have done a vertical mount for the motherboard encased in acrylic. That would have looked really cool. Especially with some blinky-flashies. Enjoy Maker-Faire.

  5. Greko - May 28th, 2009 12:06 pm

    How about a mirror set-up to show the underside..?

  6. Rob - May 28th, 2009 9:15 pm

    re spills – keep a battery powered vac and some compressed air handy. If someone does make a mess, if you act fast you can probably avoid disaster. That said, I hope all your 7400 IC’s are socketed 🙂

  7. Nick - May 30th, 2009 9:34 am

    Nice project! Though it would cost some more money, have you thought about putting it into an acrylic case so people can see it? Then, you could mount a fan underneath (liquid cant spill upwards can it?) and then a fan on the top with a directional vent facing away from the audience. This This would prevent anyone from spilling anything on it and ruining it. Anyway, just a thought.

  8. Doug Parker - June 9th, 2009 8:45 am

    #4 There’s a simple solution to this. Email me–you have my email.

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