Re: Graphics Tablet...

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

Dosius wrote:

>mjmahon@aol.com (Michael J. Mahon) wrote in message
>news:<20030724185433.28226.00000584@mb-m24.aol.com>...
>> Jeff Thomas asked:
>> 
>> >I have heard of people making their own "light pens" for Apple II, but
>> >has anyone ever built a graphics tablet which connects to the joystick
>> >port?
>> 
>> Light pens for the Apple II series come in two basic flavors: "fast"
>> pens which connect to a card (either a special card or an 80-column
>> card), and "slow" pens which connect to the joystick port.
>> 
>> The slow pens are simply a directed CdS photoresistor, whose
>> changing resistance in response to light can be sensed as a
>> "paddle" input to the Apple II.  It can be used in conjuction with
>> software to identify what screen item is being pointed at by
>> sequentially blinking the screen elements while looking for
>> a change in the CdS cell resistance.  As you can imagine,
>> this is pretty slow if there are more than a few things on the
>> screen, but it can be used satisfactorily to select from a
>> menu.
>> 
>> Resistive "graphics input devices" were made by Koala and
>> a few knock-off companies.  These KoalaPad devices are
>> fairly inexpensive and quite simple.  They should still be
>> available in the resale markets.  They are used like a
>> joystick, but are easier to control for drawing.
>> 
>> -michael
>> 
>> Check out amazing quality 8-bit Apple sound on my
>> Home page:  http://members.aol.com/MJMahon/
>
>Hm.  What about TouchWindow?  I always thought that was leet. (Joystick port)

Yep, they were an independent design, basically similar to the
KoalaPad, but with transparent membranes.

Though not strictly graphical input devices, some "keyboards"
like the Muppet Keypad were actually pressure-sensitive pads
like the KoalaPad overlaid with "keyboard" overlays.  When a
"key" was depressed, the corresponding x,y value was read
as a joystick position and translated to an action.

-michael

Check out amazing quality 8-bit Apple sound on my
Home page:  http://members.aol.com/MJMahon/