15 Apr
2001
15 Apr
'01
8:11 p.m.
----- Original Message -----
From: Richard Erlacher <edick(a)idcomm.com>
To: <classiccmp(a)classiccmp.org>
Sent: Sunday, April 15, 2001 7:43 AM
Subject: Re: Kim / Commie keypads
The membrane types are quite a bit cheaper, hence
you'll see them most of
the
time. When you select a candidate for canibalizing,
you look at the
underside
of the PCB. If there are two contacts that are
soldered through the
board,
that's the type you want, since whatever mechanism
makes the keyboard work
in
that case is removable as a unit.
----- Original Message -----
From: "Ross Archer" <dogbert(a)mindless.com>
To: <classiccmp(a)classiccmp.org>
Sent: Sunday, April 15, 2001 5:15 AM
Subject: Re: Kim / Commie keypads
Or, I may just go this route with a keypad kit, complete
with user labels. This is what I've been looking for.
At least they claim to be good to up to 3 million cycles.
Pity the original keypad wasn't nearly that good.
The Radio Shack lead didn't turn up anything on their
website. If they do have something like this, I'd check that
out too.
-- Ross
-- Ross
http://www.grayhill.com/grayhill.nsf/9f8c4a13a816a6e58625681f0065ecd1/a10513
e0e909811086256846005a8408/$FILE/C-39-43.pdf
>
> ----- Original Message -----
> From: Richard Erlacher <edick(a)idcomm.com>
> To: <classiccmp(a)classiccmp.org>
> Sent: Saturday, April 14, 2001 9:49 PM
> Subject: Re: Kim / Commie keypads
>
>
> > I've seen attempts by others to repair keypads of the KIM-1 sort.
It's
> doomed
> > to frustration. They cost MUCH less than $1 US in the quantity in
which
> they
> > were purchased in '76, and that was >50% shipping and packaging. The
> KIM-1 was
> > designed more as a novelty than as a computer, since it was really
just
a
> > demo/evaluation kit for their ROM/I/O etc.
devices. It was designed
to
> see <
> > 1-2 hr of power-on time. Clearly they didn't need a seriously
serviceable
> > keypad for that.
> >
>
> I think the outboard keyboard & case idea is excellent, and a fun "hour
at a
> time"
> kind of project to tinker with whenever bored. :) I already took apart
one
> broken
> keyboard in my boneyard -- it was a membrane type. <:-(
>
> As for up-time, this particular KIM-1 has seen many thousands of up-time
> hours,
> being the platform on which I learned to program computers (even before
> BASIC), and that got me hooked.
> So there are obvious fond memories of discovery there.
> Even hand assembly and calculating relative branches by
> hand didn't seem too awful at the time. Just being able to write a
program
> and make it do something was far too magical to
seem tedious. :)
>
> It also spent an awful lot of time playing Microchess, Wumpus,
> Lunar Lander, Blackjack, etc. The First Book of KIM and the programmers
> reference guide were tattered almost to oblivion. :) And the keyboard
was
> a hunk of junk, you're right. I seem to
remember having trouble with
the
> "0"-"3" and "+"
keys even in the late 70's.
>
> I do agree that the board was principally aimed an engineers and the
sort
> of person who would play around just enough to
decide if this was a
family
> of chips they can use and try out a few ideas,
then go on to design
their
> own hardware, but there were some indications
that MOS expected some
> users to expand it significantly; otherwise, why supply expansion
connectors
> with all
> relevant signals and provisions to flexibly alter the on-board decoding
> externally,
> and why TTY + paper tape capabilities on top of keyboard + cassette if
it
> was just
> to bang a few bits and play long enough to make a mindshare sale? It
seems
> like
> a lot of engineering effort could have been spared if it was intended to
be
> a fixed,
> unexpandable board.
>
> It looks to me more like MOS Technologies expected some of these boards
to
> end
> up as process controllers or to be expanded, e.g. KIM-4, and not just
for
> evaluation
> service. Then hobbyists discovered it and who knows what percentage of
> total
> KIMs sold ultimately went to hobbyists for home use?
>
> -- Ross
>
>
>
>
>
> > Dick
> > ----- Original Message -----
> > From: "Tony Duell" <ard(a)p850ug1.demon.co.uk>
> > To: <classiccmp(a)classiccmp.org>
> > Sent: Saturday, April 14, 2001 4:18 PM
> > Subject: Re: Kim / Commie keypads
> >
> >
> > > >
> > > > Well, clearly, one has to know what sort of switches are in place
> before
> > >
> > > Exactly. I can think of a few keyboards that I know to be made up of
> > > individual switches, but all of them are over 10 years old, and
hence
> > > should be restored themselves, not
stripped.
> > >
> > > > deciding to use a given keyboard. Being Microswitch, it's NOT
genuine
> IBM.
> > If
> > > > the IBM real-McCoys are unuseable there's no point in attempting
to
> use one
> > of
> > >
> > > That was my original comment. The true IBM 'clicky' keyboards are
not
> > > suitable for this, for all they have a
lovely feel (I am using one
right
> > > now).
> > >
> > > > them. Hall-effect switches are probably too expensive to appear
in a
> > cheapie as
> > > > one would expect to see on a PC clone. What's called for in the
KIM-1
> case
> > is
> > >
> > > Again, agreed, but you might come across them in some (high-end)
classic
> > > computers.
> > >
> > > > clearly a switch, however. There's some question as to whether
the
> > relatively
> > >
> > > We're agreeing on everything. Yes, no point in making life
difficult.
> The
> > > Kim was designed to use a switch, and that's what should be used to
make
> > > a new keypad -- especially as suitable
switches are available.
> > >
> > > Incidentally, has the chap with the Kim tried taking the old keypad
> > > apart. Somethimes they can be mended -- broken contacts resoldered
or
replaced, for
example.
-tony