PCB vs perfboard construction economics (was Re: "New" PDP-8)

--- Ben Franchuk &lt;bfranchuk(a)jetnet.ab.ca&gt; wrote: While I can recommend a real PCB if the setup costs and the per-sq-in costs are not killing you (price an Omnibus or Unibus-sized 4-layer board, complete with gold fingers!), personally, my WW overhead isn't terrible: I rescued all the prototype hardware from my former employer when they went bust - I probably have three lifetimes worth of WW sockets. When I do a project, the only part I have to spend money on is the wire. My last project is a good case-study for expense vs. time. I wanted to replicate a scoreboard from a Dragon's Lair/Space Ace. I tried to find one on ePay, but they only come up occasionally (every couple of months). I decided to build one. I started with a couple of digital pictures, a parts list and a schematic. Since the board was approx 6"x9", it would have been somewhat expensive for a commercially-made PCB. There are still plenty of surplus units out there that sell used for under $50 when they are available, so it would be cheaper to wait for a sale than to have a professional PCB created unless the new PCB added value somehow. I had the blue perfboard (from when the MicroCenter got rid of all of their prototyping hardware at 80% off list!), the wire and the discrete components. I had to purchase the LEDs ($0.65 each) and the driver chips (a few bucks each). Total out-of-pocket expense was <$25. I probably pulled about $15-$20-worth of supplies out of my parts bins. Construction took place over several evenings, watching the sci-fi channel, tacking down point-to-point connections (didn't have the vertical clearance for socketing the LEDs). I'm pleased that it worked the first time! - pictures at http://penguincentral.com/retrocomputing/retrogaming/ under the "LED Scoreboard" link. Mostly, it's pictures of the glow of the LEDs, but there's one out-of-focus, flash-burned picture of the perfboard and yellow wire in there (the Apple QT150 has about a 24" min focal distance without the strap-on lens). The upshot was that if this were being done for anyone but me personally, it would have been an economic disaster. Nobody would have paid me a reasonable amount for that much work - it would have been much cheaper to go to an arcade service company and *buy* a used scoreboard than spend 10+ hours wiring up a board. It would have been much cheaper than that to wait out the next wave of offerings on eBay (which I accidentally did - the project took so long to complete that I _did_ pick a real one up for around $30, after I was 95% finished with my replica. The good news is that it made a nice functional benchmark to prove that mine worked). So I chose to trade my time for semi-instant gratification. I would have loved to have done a PCB, but I chose not to spend the time with layout tape and a blank board, and I chose not to pay to register a demo-ware layout package so I could make a 6"x9" board. If I were to make the new PDP-8 design that kicked off this whole thread, I'm not sure if I'd get professional boards (~$200/set, in small quantities, according to the designer, for a couple of 4-layer boards) or I'd point-to-point it. In terms of $$$/hour, even $200 for a board set is cheap. In terms of a discretionary hobby, $200 is a lot to divert from other projects when I already _have_ a working PDP-8. With that kind of money, I could start trolling for a Qbus SCSI controller! Back to the initial topic, though, I'd love to get a good buy on a dozen or so spools of kynar-coated wire. I'd prefer an assortment of colors, but I'd take it in whatever I could get - yellow, red, white... Anyone have a lead on any surplus places that have it for a few bucks a spool? -ethan __________________________________________________ Do You Yahoo!? Yahoo! Greetings - send holiday greetings for Easter, Passover http://greetings.yahoo.com/