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

From: Michael Holley <swtpc6800_at_attbi.com>
Date: Mon Apr 1 22:20:16 2002

I used to do all of my stuff on wire-wrap. I am now building classic
computer board that I want to show off and a PCB looks so much better. I
have done a few circuit boards from ExpressPCB and really like it.

Michael Holley

----- Original Message -----
From: "Ethan Dicks" <erd_6502_at_yahoo.com>
To: <classiccmp_at_classiccmp.org>
Sent: Monday, April 01, 2002 2:35 PM
Subject: PCB vs perfboard construction economics (was Re: "New" PDP-8)

> --- Ben Franchuk <bfranchuk_at_jetnet.ab.ca> wrote:
> > ...The board will be about 8" x 7" and $175 canadian for two
> > prototype boards. Wire wrap sockets/wire/protoboard would cost me
> 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
> 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
> 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
> 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
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Received on Mon Apr 01 2002 - 22:20:16 BST

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