Kim / Commie keypads

From: Richard Erlacher <edick_at_idcomm.com>
Date: Sun Apr 15 09:43:14 2001

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_at_mindless.com>
To: <classiccmp_at_classiccmp.org>
Sent: Sunday, April 15, 2001 5:15 AM
Subject: Re: Kim / Commie keypads


>
> ----- Original Message -----
> From: Richard Erlacher <edick_at_idcomm.com>
> To: <classiccmp_at_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_at_p850ug1.demon.co.uk>
> > To: <classiccmp_at_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
> > >
> > >
> >
>
>
Received on Sun Apr 15 2001 - 09:43:14 BST