Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!watmath!clyde!caip!think!nike!lll-crg!lll-lcc!unisoft!dual!ptsfa!ski!dr From: dr@ski.UUCP (David Robins) Newsgroups: net.micro.apple Subject: Re: Apple IIe and IIc raster scan synchronization. Message-ID: <326@ski.UUCP> Date: Mon, 29-Sep-86 15:30:13 EDT Article-I.D.: ski.326 Posted: Mon Sep 29 15:30:13 1986 Date-Received: Wed, 1-Oct-86 01:43:19 EDT Reply-To: dr@unix.UUCP (David Robins) Organization: Smith-Kettlewell Institute, S.F., CA. Lines: 44 In article <> ir332@sdcc6.ucsd.EDU (Jeff Miller) writes: >I need to synchronize a program with some fixed point in the video >display cycle (i.e. raster scan) on IIe's and IIc's. I have done >this on II+'s by wiring a certain pin into the game port, and then >reading the status of the game port. I would like to do the same >thing for the other II machines, but I don't know which pin it is >(or even whether there still is one that will work). To boot, I >can barely solder, so don't refer me to some technical specs. >Anybody out there who can help for either machine? Thanks. >-- > Jeff Miller ARPA: sdcc6!ir332@ucsd.edu > U. C. San Diego (I think) > Dept Psychology, C-009 > La Jolla, CA 92093 There are both hardware and software ways to do this. They are both described in the books "Enhancing Your Apple II", Volumes 1 and 2, by Don Lancaster (SAMS Books Publications). The hardware solution uses the SW3 on the game port, and is described in Volume 1, as Enhancement 4 FIELD SYNC. The software in the same chapter (assembly lang. routine, called from a BASIC demo program) shows how it is used. All soldering takes place on two IC sockets, which are then inserted between two IC's on the board. This is apparently for the Apple II or II+. The strictly software solution is in Volume 2, Enhancement 13; "THE VAPORLOCK". It is an ungrade of Enhancement 4., and it works on "the II, II+, //c, or //e". It gives you a fast and exect lock to video timing without needing any hardware modifications. -Dave -- ==================================================================== David Robins, M.D. Smith-Kettlewell Eye Research Foundation (previously known as: Smith-Kettlewell Institute of Visual Sciences) 2232 Webster St; San Francisco CA 94115 415/561-1705 (voice) {ihnp4,qantel,dual}!ptsfa!ski!dr The opinions expressed herein do not reflect the opinion of the Institute!