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Need a keyboard matrix for the original Apple II and II plus

VERAULT

VERAULT

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Jan 30, 2012
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Connecticut, USA
I am trying to fix a datanetics keyboard on an original Apple II and need a copy of the keyboard matrix so I can determine which keys are actually failing in the row and collumons since I am chasing alot of ghosts.

Anyone have one? Google seems to just point me to a IIe matrix and Mike Willegals page on adapting a datanetics to the Apple 1
 
Anyone?

Just looking for a diagram or schematic which shows which characters are on which rows and collumns. For instance I know I have an issue with the "2@" key and the "Y" key so they are more than likey tied to one or the other lines.
 
VERAULT said:
I am trying to fix a datanetics keyboard on an original Apple II and need a copy of the keyboard matrix so I can determine which keys are actually failing in the row and collumons since I am chasing alot of ghosts.

Anyone have one? Google seems to just point me to a IIe matrix and Mike Willegals page on adapting a datanetics to the Apple 1
Click to expand...
Are you sure it's the keys themselves, and not the encoder board (assuming there is one?)

I chased down a similar problem recently, where keypresses would produce multiples of the same keystroke. At first I figured it was an electrical issue with the contacts or with the switches themselves, but, on a hunch, I replaced the encoder board...and problem solved.
 
no encoder board. that error cut and dry means KB not connected. so its the cable or the circuitry.

I repaired a fried keytronic keyboard to a franklin 1200 pc on an old thread. it was connected backwards. one of the calsualties was the rom. youll just need to take it apart and investigate.
 
Both of these unfortunately are for a completely different model datanetics keyboard. Not the one that apple Sold on the Original model II
 
VERAULT said:
Both of these unfortunately are for a completely different model datanetics keyboard. Not the one that apple Sold on the Original model II
Click to expand...

The only other approach I can think to suggest is ugly, untested, and time-consuming...

Hook up a multimeter in continuity mode, with one probe clipped to ground. Then, hold down a key on the keyboard, and sort of slowly strum the edge connector with the other probe like a harpist plays a harp. One of those pins will probably beep--When it does, write down the letter/pin combo in a spreadsheet, and systematically map it out/back-engineer it like that, maybe?
 
Im afraid I dont have that much time to burn. I would assume the pins on the apple II keyboard controller are fairly well documented. I just wanted someone to point me to a document which already explains which pin does what. I guess in a sense the model of KB is irrelevant as the pins would be standard across the board.
 
It actually may not be that much work, come to think of it. It may not require mapping out every single key, so much -- My guess is that every keypress will likely light up two pins... essentially a row, and column pin. By that I mean, there's no point in testing the whole sequence of QWERTYUIOP; if there's a common pin among just two of those letters ...(pick two randomly like W and O)...then it's a safe assumption that _that_ pin is the "row" pin for that line of keys. ASDFGHJKL will have a different row pin, ZXCVBNM a different row pin, etc. Same logic on columns.

Do you have a photo of the board itself? You may have posted one, I dont think I saw it.
 
Here's the pinout for the keyboard interface per the Jan '78 redbook..is this helpful?

1661784672323.png
 
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