This
is one of the most common keyboards that can be found with an
Apple 1. Here is a link to an original set of directions
about
how to connect this keyboard to an Apple 1.
When I
get a chance I'll clarify and provide more understandable instructions. http://www.applefritter.com/node/2809?res=original
I
am working on building a reproduction. As part of
the reproduction process, I reverse engineered the board and created a
set of
schematics.
Parts
Datanetics
Inc. made
their own patented keyswitches. I've run across two types of
these keyswitches, those with straight stems and those with slanted
stems, as shown below. The Datanetics rev B used switches
with
slanted stems.
As
far as I can tell, sources for original new keyswitches and caps are
non-existant. However, very early Apple II and Apple II plus
computers used keyboards made by Datanetics. Most of the keycap set
used by Apple is close enough to the Datanetics keyboards to be useful.
Early Apple II plus computers may be considered the only
likely
source for these Datanetics keyswitches and key caps.
The
other difficulty is the keyboard encoder. This part is a
National Semiconductor MM5740/AAE. This part is difficult,
and
sometimes impossible to find. When you do find them, they
frequently come with a mysterious defect that causes randomly repeating
key strokes. They are also sensitive to static electricity,
so
handle them with care, if you do find one. If you can't find
a
working one, a micro-controller could be programmed to perform the same
function. It would have to be mounted on a daughter card,
because
the power connections on the MM5740 are in non-standard locations.
Stiffener Dimentions
Here
is a not to scale rough drawing of the stiffeners used by the
Datanetics keyboard.
Datanetics Rev b
Reproduction
Here
is my reproduction Datanetics rev B connected to the Mimeo. See my blog
for more information about it.
Note: I have sold all of these and currently don't have plans to make more.
