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Re: Apple II keyboard encoder - need specs for optional right-angle slide switch

On Wed, 9 May 2012, Michael J. Mahon wrote:


Ralph wrote:

I'm trying to track down details on adding a keyswitch to the Apple II
plus keyboard encoder.

I have a vague recollection of a specific "Apple Cart" article from an
1980 or 1981 issue of Creative Computing, it discusses the keyboard
encoder board on the Apple II plus, and mentions the specific C&K
switch part number that can be soldered onto the board to achieve
full character set generation (upper and lower case ASCII, and getting
ctrl-shift-P to generate the '@' sign) from the normally upper-case
ASCII only keyboard.  I did ask a few people in person over last
weekend, but they unsurprisingly couldn't come up with an exact part #
after 30 years.
(Atariarchives doesn't have these Creative Computings scanned in)

Thanks!

- Ralph

BTW, I found this gem of an article from M. Horton (previously at Bell
Labs), posted in 1983 - linking offsite

http://www.megalextoria.com/usenet-archive/news042f1/b62/net/internat/00000317.html
(well-formatted ASCII version)

http://groups.google.com/group/net.internat/msg/a319f7b375fc6e55
(mangled Google Groups version)


Interesting article on a fundamentally broken topic: keyboards.

WRT the encoder board having an unfilled position for a switch
that "normalizes" the ][+ keyboard, wow--how could such a common
desire be so easily filled and yet remain so obscure?
It should be simple, since upper and lower case are identical except for a couple of bits. Indeed, control characters are the same, minus the high bits: 
         A  $41  1000001
         a  $61  1100001
    ctrl-A  $01  0000001
A few gates can start playing with the output of the encoder, which may be what the first poster is not fully remembering.
I don't have the schematic for the Apple II handy, so I don't remember what's in there. 

   Michael