Re: Shift-key modification?

[pausch@saaf.se (Paul Schlyter)]

In article <3BB0DDF3.5030508@mts.net>, Mike Pfaiffer  <pfaiffer@mts.net> wrote:
 
> Ernest wrote:
> 
>> What is the "shift-key modification," on the Apple II+? How do you do it?
>> 
>> Thanks.
>> 
>> Ernest
> 
> Actually it is a fairly simple procedure. It only works with a couple of 
> applications.
 
In the world of Apple DOS or ProDOS software, yes, but not in the
world of Apple CP/M.  Read on.....
 
> It amounts to running a wire from one of the exposed pins 
> of the keyboard connector (check your manual to determine which one) 
> over to button 2 of the paddle controller. The result allows certain 
> programs to input lowercase. Of course you need an 80 column card or 
> software which uses graphics in order to actually *see* lowercase.
 
I modified my own Apple II+ this way some decades ago, but as you
point out, it doesn't work with most Apple DOS/ProDOS software since
they usually talked to the keyboard hardware directly.
 
But when running Apple CP/M, this shift-key modification was really
really useful, because of three reasons:
 
1. CP/M software calls a CP/M function when reading the keyboard.
Thus, if that shift-key modification is accompanied with the
appropriate modifications to the "keyboard read" function in the CP/M
BIOS, lower-case keyboard input will be visible to *all* CP/M
software, not just a few "shift-key modification aware" programs.
Of course CP/M did it the right way: dealing with shift key
modification stuff belongs to the OS, not to the applications!
 
2. Since CP/M software ran not just on the Apple II but also on a lot
of other computers (most of them having lowercase keyboard input), a
lot of CP/M software took the availability of lowercase keyboard
input for granted.
 
3. Since a lot of CP/M software required a screen width greater than
40 characters, you had to have an 80-column video card on your
Apple II if you wanted running CP/M programs to be enjoyable.  And
with the 80-column video card you also got the ability to display
lower-case letters!
 
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