grover@potomac.dc.ads.com (Mark D. Grover) (03/18/87)
I would like any references, vendor pointers, personal experience or
reviews regarding buying, installing or programming an interface for a
PISTOL GRIP as an RS-232 serial device. (I use Sun 3 and Symbolics
machines).
Alternately, pointers to any standard reference on joysticks would be
useful. However, I am not interested in attaching it to a micro. Many thanks!
- MDG -
(Our site is still in transition. Please use the mail address below.
Automatically generated reply fields may not work.)
--
Mark D. Grover (grover@ads.ARPA) UUCP: {sun,seismo}!sundc!potomac!grover
Advanced Decision Systems 1500 Wilson Blvd #600; Arlington, VA 22209
"I've been ionized... but I'm all right now."oster@lapis.berkeley.edu (David Phillip Oster) (03/20/87)
A micro-computer joystick such as those on Atari and Commodore products is just a set of 5 normally open switches: fire left right up down The easiest way to use these is to use a parallel interface port on your computer. wire the input pins so that they are pulled high (by being connected to a 5 volt supply through 5k or 10k ohm resistors.) and are pulled to ground when the joystick switch is pushed. (Don't short the power supply to ground!) The computer will see this a 1 for a switch open and a zero for a switch closed. At most three of these can be on at one time. (fire, left, and down, for instance) mechanical mice often have a similar setup, but 3 switches (at least) per left<->right, up<->down. The direction of rotation is determined by whether the pattern of switch closures is 1-2-3-1-2-3 or 3-2-1-3-2-1. Apple II and IBM Pc joysticks are a fire button, a left-right potentiometer and a up-down potentiometer. To use these, you hook the pot to a voltage source and stick a a-d converter on it to get a number into your computer. (IBM and Apple just charge a capacitor, then count to see how long it takes the cap to discharge through the pot down to a reference voltage.) Often, for a big computer, the easiest way to equip it with joy-sticks is to buy or borrow an Apple ][, IBM PC, Atari 400, or Commodore 64, equipped with a joystick and an rs232 port, and have it run a small program that continually copies the joystick state to the serial port. Radio Shack Model 100 (battery operated, lcd display computers) can be found in clone form as the KyoComputer 150 new for $150.00 equipped with a suitable serial port and a parallel port that provides the correct input pins and voltages to drive them, needing only a custom joystick cable. --- David Phillip Oster -- "We live in a Global Village." Arpa: oster@lapis.berkeley.edu -- Uucp: ucbvax!ucblapis!oster -- "You are Number Six."