Re: Apple ][+ question

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

nogard@cishollywood.com wrote:
> Just picked up another Apple ][+, and have a question.  There seems a
> be a wire running from 74ls251 pin 16 (the right lowest pin with the
> keyboard facing you) down to ??? (seems to have been dislodged over
> time).  I was thinking this was the shift key mod, but it seems to be
> connected the the chip below the game port.  Now somebody could of
> have just attached it randomly, I have no idea.  I was just curious
> where I would need to attach the other end?
> Also if this helps, it seems to have the Applied Engineering Lower
> Case Rom Chip (Rev LC 1.0).

> Sorry the grabbette is connected to pin 9 not 16 or 74LS251.

The Lower Case ROM is a dead giveaway that the machine would
be shift key modified.

If by "lowest" pin, you mean closest to the keyboard, then the
pin you describe is pin 1, which is the PB2 input--the usual
place for the shift key mod to be connected.  The other end of
the wire should go to the high (non-ground) side of the shift key,
or pin 2 of U4 on the keyboard encoder board.

There are spare wires/pins on the keyboard connector(s), and some
people modified their encoder boards to pipe the high side of the
shift key to an unused pin of the main board keyboard connector.
This approach allows a "clean" shift key mod, without flying wires.
(The connection to the game port or the '251 can be made with a wire
under the board, for an even cleaner installation.)

-michael

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