Re: A plea: Looking for a working MM5740AAE/N for Apple II Keyboard

[Michael J. Mahon <mjmahon@aol.com>]

rittwage <rittwage@gmail.com> wrote:
> On Dec 7, 2:49 am, "Michael J. Mahon" <mjma...@aol.com> wrote:
>> rittwage wrote:
>>> I have an old Apple II that I've fixed every other odd problem
>>> (besides a broken Applesoft E0 ROM) except the keyboard!
>> 
>>> I found some AAC/N chips, but no luck- the encoding is wrong.  I need
>>> to see if any kind soul has any AAE/N encoder chips left to spare.
>> 
>>> I really hate to convert to PS/2- I like the original keyboard.
>>> Without that, I might as well use an emulator.  :)
>> 
>> Pete, I'd recommend keeping this thread in csa2 and avoiding
>> crossposting to marketplace and emulators.
>> 
>> Are you sure that the problem is the encoder chip, and not
>> one or more shorted keyswitches?  Failed encoders are not
>> the most common keyboard problems.
>> 
>> If it is the encoder, then you will have a hard time finding
>> an equivalent replacement.  It would be possible to construct
>> an equivalent that plugs into the original electrical "footprint",
>> but it's not a simple project.
>> 
>> Since the encoder presents parallel ASCII to the Apple II, it
>> should not be too difficult to replace the keyboard with, say,
>> a later Apple ][+ keyboard.  Those used to be pretty plentiful,
>> depending on how authentically "Apple" it had to be...
>> 
>> -michael
> 
> It's definitely the encoder- the original does nothing and the AAC
> works, but has all wrong keys.  No switches are shorted, and I traced
> to find no "stuck" bits.  It's just that the AAC, AAD, etc. send
> different keystrokes to the AAE.
> 
> This is an early Datanetics keyboard without the separate encoder
> board, so that modern encoder board replacement won't work.  Also, I
> know I can replace the keyboard entirely with a PIC and a PS/2
> keyboard, but... yuck.  I know I can also swap the whole keyboard for
> another, but they are about as hard to find!
> 
> I do have extra IIe keyboards, but to my knowledge they can't be
> converted.  Or can they?
> 
> -Pete

Yes, it shouldn't be hard to adapt a //e keyboard to an Apple II.  You'll
need to stay in caps lock to keep things simple. 

-michael - NadaNet 3.1 and AppleCrate II: http://home.comcast.net/~mjmahon