Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site pur-ee.UUCP Path: utzoo!watmath!clyde!burl!ulysses!mhuxj!houxm!ihnp4!inuxc!pur-ee!ecn-ee!dunkelbe From: dunkelbe@ecn-ee.UUCP Newsgroups: net.micro.cbm Subject: Re: C64 Mouse Message-ID: <2207@pur-ee.UUCP> Date: Thu, 4-Oct-84 03:36:20 EDT Article-I.D.: pur-ee.2207 Posted: Thu Oct 4 03:36:20 1984 Date-Received: Fri, 5-Oct-84 05:31:22 EDT Sender: notes@pur-ee.UUCP Organization: Electrical Engineering Department , Purdue University Lines: 27 Nf-ID: #R:zinfandel:19800012:ecn-ee:19300005:000:1047 Nf-From: ecn-ee!dunkelbe Oct 3 10:47:00 1984The C64 has two pot inputs on the video chip which are most consistantly read by syncing with the video. In other words, always check the raster register and read on the same line of video to prevent jitter on the value read back from the analog inputs. If the RS mouse is like any of the others I have seen, it will be sending pulses down the switch oriented joystick lines just as if the user was repeatedly moving the joystick one of the four directions and letting it come back to center. I would be surprised if the mouse had any type of pot action since all software would have to take into account the wrap-around for every rotation of the wheel. The programmer's reference manual has all the info you need. For the pot interface, refer to the VIC chip description section. The joysticks are connected to a parallel port which normally runs the keyboard. With a little bit of machine language programming, you could get a neat little interrupt driven mouse routine for $40. Kirk Dunkelberger pur-ee