Well, it is harder to do, and more expensive, but I
personally find it more rewarding to hunt down old
parts and have those parts period-authentic. For
example, the Motorola 6800 I'm building uses a
Motorola 6820 (surprisingly hard to find compared to a
6821) and an MC6871 hybrid clock generator in a can,
also period and very hard to find (even the SWTPC used
its cheaper 6875 successor and a separate crystal). I
like to use ceramic/gold chips be the original maker
of the chip for machines I'll display. I suppose, if
all I wanted to do was "run" these machines, I could
just load an emulator and be done with it. Weird,
perhaps - maybe its because I couldn't afford even the
parts to build these when I was in high school(and
would be less likely to succeed in making them work or
programming them).
--- Richard Erlacher <edick_at_idcomm.com> wrote:
> What I've encountered more and more is the
> inconvenience associated with
> trying to use current-generation components in
> wire-wrap. I'm always having
> to build adapters that make a DIP out of a TSSOP or
> the like. The adapters in
> a prototype often exceed the cost of a PCB. It's
> much easier to build small
> boards, about the size of a typical playing card,
> and that's enough space to
> house a microcomputer of reasonable capability,
> comparable with any "classic"
> 8-bitter of the '70's and '80's, including its I/O,
> memory, video, and mass
> storage interfaces. After I get the current task
> off the table, I'll take a
> closer look, but it seems to me that it's easier to
> put a system on a
> playing-card sized board, and cheaper too, using
> current technology, than to
> recreate the old stuff using parts that are
> increasingly scarce and boards
> that are needlessly large and costly.
>
> Dick
>
> ----- Original Message -----
> From: "Ethan Dicks" <erd_6502_at_yahoo.com>
> To: <classiccmp_at_classiccmp.org>
> Sent: Monday, April 01, 2002 3:35 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 $100...
> >
> > 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
> >
> >
> > __________________________________________________
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> >
> >
>
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Received on Tue Apr 02 2002 - 00:49:22 BST