Path: utzoo!utgpu!attcan!uunet!husc6!bbn!rochester!pt.cs.cmu.edu!andrew.cmu.edu!kg0r+ From: kg0r+@andrew.cmu.edu (Kenneth Gober) Newsgroups: comp.sys.ibm.pc Subject: Re: Using a Joystick instead of a Mouse Message-ID: Date: 3 Aug 88 21:17:05 GMT References: <6069@chinet.UUCP> Organization: Carnegie Mellon Lines: 34 In article <6069@chinet.UUCP>, edlee@chinet.UUCP (Edward Lee) writes: > > Have any of you plugged an Atari joystick into the serial port and used it > instead of a mouse? Doing so would make playing some games easier. It is unfortunate that both the 9-Pin Serial Port and the Atari Game Port look identical, because they're not. If by Atari joystick, you mean the ones used with the 2600, 400 and 800; the ones that work with Commodore 64's also, then I say you can't do it (easily). Such a joystick consists of 4 small switches for movement (up, down, right, left; diagonals are combinations: e.g. down+left) and 1 small switch for the single fire button. Ignoring the fact that most mice have 2 or more buttons, the problem is: How do you build a circuit that translates the 5 switches coming in on 5 wires (parallel data) into a stream of (correctly encoded) pulses on 1 wire (serial data)? Some joysticks (Apple II joysticks, for instance) have 2 switches for the 2 fire buttons (digital signals- either on or off) and 2 wires which carry the X and Y position of the stick (analog signals- varying voltage). Since a serial port is digital, you would have to convert the analog signals to digital, then translate them into serial data. You would also have to decide if you wanted the joystick to indicate absolute position (centered joystick moves cursor to center of screen) or indicate movement direction (centered joystick means sit still). You may have to rewrite the mouse driver (usually called MOUSE.SYS on MS-DOS machines) or the game software itself if it includes its own driver. Both cases require a hardware adapter which you would have to build yourself. They also require you to have intimate knowledge of the protocols a mouse uses (there are many; choose which kind of mouse you want to emulate). It sounds like more trouble than it's worth. Kenneth Gober kg0r@andrew.cmu.edu