Megalextoria
Retro computing and gaming, sci-fi books, tv and movies and other geeky stuff.

Home » Archive » net.micro.apple » Shift key mod
Show: Today's Messages :: Show Polls :: Message Navigator
E-mail to friend 
Switch to threaded view of this topic Create a new topic Submit Reply
Shift key mod [message #72469] Sat, 25 May 2013 10:27 Go to next message
"SchellSteph&quo is currently offline  "SchellSteph&quo
Messages: 3
Registered: May 2013
Karma: 0
Junior Member
Message-ID: <12439@sri-arpa.UUCP>
Date: Tue, 14-Aug-84 12:45:00 EDT
Article-I.D.: sri-arpa.12439
Posted: Tue Aug 14 12:45:00 1984
Date-Received: Thu, 16-Aug-84 02:18:39 EDT
Lines: 8


     I realize this is sort of behind the times, but could someone describe
the modification to the Apple ][+ keyboard that enables transmission of
both upper and lower case ?  I have heard that it is a simple one wire
mod.    Thanks in advance !

                     Stephan Schell
                     schell@lll-mfe
Re: Shift key mod [message #72475 is a reply to message #72469] Sat, 25 May 2013 10:27 Go to previous messageGo to next message
Thomka.es is currently offline  Thomka.es
Messages: 14
Registered: May 2013
Karma: 0
Junior Member
Message-ID: <12503@sri-arpa.UUCP>
Date: Wed, 15-Aug-84 22:33:00 EDT
Article-I.D.: sri-arpa.12503
Posted: Wed Aug 15 22:33:00 1984
Date-Received: Sun, 19-Aug-84 01:40:55 EDT
Lines: 77

-------------------
To the AppleUsers^.es dl:
A question was raised by someone on the info-apple at Arpa (and
alternately the XeroxInfo-Apple^.pa dl).  The question brought this
response from me.  Since I thought it may be useful information to those
of you that are not on those dl's I've decided to "fill you guys in".


The question was:
" . . . could someone describe the modification to the Apple ][+
keyboard that enables transmission of both upper and lower case ?  I
have heard that it is a simple one wire mod."
-------------------

The one wire added is the signal line of the actual SHIFT key to pin 4
of the "Game I/O" (the 16 pin socket that the paddles plug into).  Pin 4
is a typically unused pin of the Game I/O, but if you look it up there
is an input designated for it.  That input is PushButton 2 (PB2).
Almost everybody has no need for PB2, (PB0 and PB1 are the ones used on
the paddles or joysticks).  Knowing that, somebody (not of Apple, but of
some software manufacturer) decided to provide some nice feature there,
the "one wire shift mod".

If you have the newer 2 piece keyboard (also called the "piggyback
keyboard) identifiable by the small board hanging under the keyboard,
and connected to the keyboard by 25 in-line pins (each pin is about 1"
long) then the SHIFT signal you want is actually pin 24 of that 25 pin
connection.

If you have the old one piece keyboard, where all of the keyboard keys
and the encoder chip and some other chips are all located on the same
board, then you will have to locate the SHIFT line yourself.

Whatever; once you find that SHIFT signal (its normally high [about 5
volts] until you press SHIFT, then it is held to ground [0 volts]) you
then wire it to pin 4 of the Game I/O.  If you use a wire with clips on
the ends you will then be able to easily remove it if you ever have to.

HOW THE DARN THING GIVES LOWERCASE

It doesn't!

All this one wire shift mod does is give a signal to the pin 4 of the
Game I/O which indicates if the SHIFT key is being pressed.  The one
wire shift mod does not give lowercase.  It is up to software (or
firmware) running in the Apple to recognize that SHIFT signal and
properly interpret (or re-interpret) the real keyboard UPPERCASE
characters into the desired lowercase characters.

Now that that is out of the way.  You might like to know that all is not
bleak,  many of the newer software packages that have any need for you
to ever enter lowecase characters (word processors come to mind, mainly)
have the proper coding to continually read that pin 4 of the Game I/O,
whether or not you have the one wire shift mod in.  That way, if you do,
the keyboard will be re-interpretted otherwise the keyboard will be read
as is.

Lastly, this "one wire shift mod" will work on any Apple.  Generally,
there is no need for it in the Apple IIe or the Apple IIc, since both of
them have real UPPER/lowercase keyboards.  But, there is always the
exception!  Some software running on any kind of an Apple can make use
of the additional information of whether or not you are pressing the
SHIFT key, regardless of the kind of Apple you have.  For example
normally there is no difference between a ctrl-q and a ctrl-Q.  Both
send the same ASCII code to the Apple motherboard, BUT with the "one
wire shift mod" you can now recognize (if you have software reading PB2)
the difference and handle them in different ways.  This gives you about
another 26 new control character possibilities! (there are 26 letters in
the alphabet but there are 32 control codes AND BUT some of the
characters won't be available).

(Note: The Apple IIe rev. A and rev. B motherboards have another
difference!  One of them, and I'm not sure which, has the "one wire
shift mod" already wired in.  There are other differences too, but
that's one you might not have known about.)

	Chuck
Re: Shift key mod [message #73961 is a reply to message #72469] Sun, 26 May 2013 20:29 Go to previous message
julian is currently offline  julian
Messages: 52
Registered: May 2013
Karma: 0
Member
Message-ID: <3149@ecsvax.UUCP>
Date: Sat, 25-Aug-84 11:24:23 EDT
Article-I.D.: ecsvax.3149
Posted: Sat Aug 25 11:24:23 1984
Date-Received: Thu, 30-Aug-84 07:47:57 EDT
References: sri-arpa.12439
Lines: 18

Some of the available explanations on the shift key mod can be a bit confusing,
especially when it comes to pulling off key caps and soldering wires.

You should first get some good clip leads, with small ends,  the kind that
CE's use -- the leads should clip on to a wire with a small hook and have a
push button on the top.  You need one wire with leads on each end.

Refer to page 10 of the Apple Reference manual.  Below the white box around
'Game I/O' in the chart, you will see a chip.  You attach one clip lead to
the lower right piece of the chip.  The other end is attaced to the keyboard
encoder in this way -- face the apple with the keboard closest to you, peek
your head inside the box and look back at a row of exposed vertical pins about
an inch or so long...you attach the wire to the 2nd pin from the far right.
This works only for 'recent' apple keyboards, which you have if you bought you
apple in the last few years.

Phil Julian
mcnc!ecsvax!julian
  Switch to threaded view of this topic Create a new topic Submit Reply
Previous Topic: Apple 2e advice needed
Next Topic: Termcap & emulator for Apple ][
Goto Forum:
  

-=] Back to Top [=-
[ Syndicate this forum (XML) ] [ RSS ] [ PDF ]

Current Time: Wed Jul 06 16:22:12 EDT 2022

Total time taken to generate the page: 0.00758 seconds