Re: Question about keyboards

[Wayne Stewart <waynes@intergate.ca>]

Ernest wrote:

> I have an external keyboard that was used on a German A2 clone, and I was
> wondering if there is away to use this keyboard in conjunction with a normal
> (case mounted) keyboard. My idea was to (in theory) build a keyboard
> splitting device that both the external and internal keyboards plug into,
> that could be controlled by toggling a switch before turning the computer
> on.
>
> I don't have any idea of how to build a device like this but I was curious
> to know if it could be done very easily? I have a similar ROM switching
> device on an A2+, and it seems that if it could be done with a ROM, why not
> a keyboard?
>
> I was also wondering about the different keyboards used on the Apple II's
> and clones. The Apple II and IIe have different keyboards, and the IIe
> Platinum has the numeric keypad, etc. Then, some of the clones have numeric
> keypads but no Open/Closed apple keys, or no keypad at all, etc.
>
> My question is... what allows one keyboard to work on one system but not
> another? Where is that controlled? I mean, if you can switch different
> keyboards (simple and with numeric pads) between different clones, would you
> be able to switch a IIe and Platinum IIe keyboard between each other? Are
> these old clone keyboards controlled by the character ROM on the
> motherboard, or by a chip on the keyboard circuit board? How does all this
> work?

Any IIe keyboard will work with any IIe motherboard, whether it be a platinum,
beige or whatever.
With the IIe all the keyboard is, is a bunch of switches, everthing else
including
the controller(AY3600) is on the IIe motherboard. So basically every key press
is just crossing two of those 26 wires. A simple y connector would allow to to
use 2 different keyboards at the same time or 50.

The II+ or II does it a bit differently having the MM5740 on the keyboard or
the
AY3600 on the keyboard encoder board. I've never tried it but an adapter with
switches for the 5 and 12 volt power might work.

Out of curiosity I tried clone keyboards on a II+ but that was some years ago.
I didn't have a lower case ROM for the II+ back then but other than being in
upper case only it worked fine. I recall in one case the keyboard shortcuts in
the clone keyboard also worked.

    Wayne