jea@prodigal.psych.rochester.edu (Joanne Albano) (11/15/90)
Does anyone have a parts list for a mouse <=> joystick switch for port one? What kinda switch should I use? Joanne jea@cvs.rochester.edu
mueller@hatteras.cs.unc.edu (Carl Mueller) (11/15/90)
In article <10412@ur-cc.UUCP> jea@prodigal.psych.rochester.edu (Joanne Albano) writes: >Does anyone have a parts list for a mouse <=> joystick >switch for port one? What kinda switch should I use? I've successfully used a quad 2x1 multiplexer chip to switch between a mouse and a joystick. I forget the part number; it's either 74257 or 74258 (one has inverting outputs; the one you want doesn't). Using low-power devices seems like a good idea (ie 74LS257 74LS258). The reason I used this chip is that it was easier to find than a 4-pole double-throw switch, which is what you'd need otherwise. With the chip, I just use a single-pole switch to toggle its select line. Whichever way you go, you need at least: 2 DB-9 plugs (male) 1 DB-9 socket (female) wire Also nice would be something to hold all the pieces together (like a box). You can get away with just using the wire, but it's kinda messy, especially if you use the chip (in which case a small circuit board isn't a bad idea). Then it's just a matter of wiring. The left-right-up-down (or the corresponding mouse signals) from each plug are hooked up the the switch/chip-inputs, and the switch/chip-outputs hook up to the corresponding pins on the socket. Hook power and ground up to both plugs, and hook the button inputs to both plugs. If you're using a switch, you're done. If using the chip, it also needs the power and ground lines, and its chip-select lines must also be hooked up to the appropriate voltages to activate the chip-outputs. The input select switch then needs one side hooked to ground, the other side to power, and the middle to the input-select for the mux chip. I'm not quite an EE-type, so there might be some debate about the chip inputs being wired satisfactorily (ie, they're left 'floating' when you switch over to a centered joystick). But what I've done seems to work. If you can find a 4PDT switch, that'd be the way to go, I guess. -Carl (mueller@cs.unc.edu)