Re: Shift-key modification?

[mjmahon@aol.com (Michael J. Mahon)]

John H Maxwell wrote:

>   I purchased my ][+ in Aug. '81 and used the shift-mod to upgrade
>my system. I ran a wire from the appropriate point on the keyboard
>PC board to the unused connector which goes down to the main board
>and ran a wire under the main system board to the PB2 connection
>of the game socket. No visible wires to get in the way

I did it the same way, John--thought it made a neat installation.

The only potential problem arises if someone wants to use PB2
(which is where the shift key gets connected) for a joystick button.
The joystick pushbutton connects PB2 to +5 when pressed, and
the shift key connects it to ground when pressed.  This produces
annoying results when both keys are pressed simultaneously.  ;-)
Adding a low-value resistor (470 or so) in series fixes the problem.

On my //e's, where the mod used to not be the default) and then
it was) with solder pads on the main board, I made the mod safe
for simultaneous pressing by bridging the pads (after cutting the
"bowtie" if necessary) with a 470-ohm resistor.

-michael

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