glen@intelca.UUCP (Glen Shires) (01/22/84)
[]
When I described the smarterm 80-column plug-in apple board, I mentioned
that it provides the ability to make the shift key work as a true shift key
for all letters if one adds the "standard shift key modification" wire. I
received a request to explain what this is, and since it may be of general
interest, I decided to post my response.
The Apple ][+ keyboard was designed to be upper-case only. Therefore, it
only generates the upper-case ASCII codes. Several 80-column display boards
allow lower-case and therefore wish to allow the user to use lower-case.
One way which is often used by several 80-column boards and some application
programs is to intercept the standard keyboard input (see KSW
p. 84 of Apple ][ Reference Manual) and to preprocess the characters.
Many boards allow a special character (often control-A) to be typed by
the user whenever he wishes to change the case.
Many boards also allow the user to make a one-wire modification to make
the shift-key work right. This is what is known as the "standard shift-key
modification". It allows the software preprocessing routine to "read" whether
or not the shift key is depressed, and act accordingly. The wire connects
the shift-key output to paddle-button-2 (PB0,PB1 are used by many games
and connected to many joysticks/paddles; PB2 is usually unused). The
keyboard preprocessing routine can then read the status of the shift key
by reading $C063.
This modification is supported by several 80-column cards and some other
application programs, read your manuals!
HOW TO DO IT:
- Open up the apple top, look down into with the keyboard side closest to you.
- Locate the board directly under the keyboard. It stands above the
mother board. It may be marked "Encoder Bd. Apple II"
- Locate the connector on the right side of this board. It has about
25 pins.
- The second pin from the right is where one end of the shift-key mod wire
goes. Connect a wire to this pin.
- Now locate the game-port socket (that's where the joysticks/paddles
plug-in)
- Pin 4 is where the other end of the shift-key mod wire goes. This pin
is in the right row of pins, fourth from the bottom. Connect the other
end of the wire to this pin.
That's it! Now most boards will automatically use the shift-key correctly.
Other boards may require that you type a certain control-character to
initiate the modification.
If you aren't the hardware hacker type, many computer stores will do this
modification for you.
^ ^ Glen Shires, Intel, Santa Clara, Ca.
O O {pur-ee,hplabs,ucbvax!amd70}!intelca!glen
>
\-/ --- stay mellow