Re: versatile interface

[Erick Wagner <wagnere@netcom.com>]

Cyrus Roton <croton@ridgecrest.ca.us> wrote:

> GAME PORT, VERSATILE INTERFACE

Cyrus provided some good information about the analog inputs of
the game port but a lot of people aren't aware of the digital
inputs or outputs.

All Apple IIs, have 4 analog inputs (GC0-GC3) which can handle
a variable resistance of up to 150K ohms and 3 digital inputs
(PB0-PB2 or SW0-SW3).  The IIgs added a fourth digital input
(PB3/SW3).  All Apple IIs except the IIc and IIc+ have a 16-pin
game port which provides 4 digital outputs (AN0-AN3).

Through some creative (but not necessarily complex) digital circuitry
(shift registers, etc.) it is possible to do some amazing things.

Vernier Software sells two books (each about US $25) that each
provide about 12 projects that are exclusively game port based;  most
of these require the 16-pin game port.  Most (but not all) of the
projects have readily available kits that can be obtained from
Vernier.  Note that you must have a copy of the book(s) *BEFORE* you
order the kits or you won't know how to assemble them.

You can visit their home page or send them email.

http://www.teleport.com/~vernier
email: dvernier@vernier.com

Tell them Erick Wagner sent you! :)