Saturday, January 23, 2010

Soldering, and joysticks

Some of the time I spent working with Mr. Alessi was actually spent just playing around. I didn't always write business software. Sometimes I would write code to draw graphics, or read BYTE magazines, or play video games on the computer.

Some of these games allowed the use of a joystick, which we didn't have. I decided to build my own. The Apple II+ supports the reading of 2 variable resistor (volume control) knobs. Many joysticks use this to provide x/y positioning.

To plug a joystick into the computer, the joystick needs to have a 16 pin DIP connector. I went to Radio Shack and bought the connector, a cable, and the joystick module preassembled. I had an old radio control car, so I took the steering controller and cut out a hole where the steering wheel was. It had button for reverse, so I used that for button 1 on the joystick. I can't remember if I added a second button. I guess I must have since it would be hard to play games without it.

The joystick came together easily with my limited soldering skills, and it worked! Thinking back on it, Mr. Alessi was remarkably okay with my plugging in a homebrew device like this into his $2400 computer. The only thing about the joystick was that the value of the potentiometers was slightly off. I didn't get the complete range of motion of a properly designed joystick. However it was good enough to play Choplifter and some other games!

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