Path: utzoo!utgpu!news-server.csri.toronto.edu!bonnie.concordia.ca!uunet!samsung!sdd.hp.com!spool.mu.edu!news.cs.indiana.edu!ux1.cso.uiuc.edu!ernie!bazyar From: bazyar@ernie (Jawaid Bazyar) Newsgroups: comp.sys.apple2 Subject: Re: Softswitches and Rom Routines Message-ID: <1991Feb10.194046.1898@ux1.cso.uiuc.edu> Date: 10 Feb 91 19:40:46 GMT References: <1991Feb7.165018.768@cunixf.cc.columbia.edu> <43942@ut-emx.uucp> Sender: news@ux1.cso.uiuc.edu (News) Reply-To: bazyar@cs.uiuc.edu (Jawaid Bazyar) Organization: Mutation Testing Facility, University of Illinois Lines: 27 In article <43942@ut-emx.uucp> daveh@ccwf.cc.utexas.edu (David H. Huang) writes: >It's new in that it's built into the GS (IWM?). If you have a Disk II >controller card in slot 6 of any Apple II, C0E2 is also stepper phase 1 low >I believe C0E9 turns the disk drive on, and accessing C0E0-C0E7 will make >the head move up one track. Accessing C0E6 C0E7 C0E4 C0E5 C0E2 C0E3 C0E0 C0E1 >will make the head move down one track (I could be wrong though, this is just >from memory). That's probably right.. BUT, don't forget that some pretty hairy timing must be done in between those accesses. Hitting one of those soft-switches turns on a magnet that starts to turn a rotor- it takes time to do this. But if you wait too long, you get poor performance. >Does anyone know how to do stuff like this with the Apple 3.5 drive (I'm >pretty sure it's possible, since the Apple 3.5 is a dumb drive, and progs >such as ZZCopy and Photonix seem to take advantage of that. There's actually an easier way to low-level the AppleDisk 3.5, and that's to use the special Smartport calls detailed in the GS Firmware Reference manual. I would guess that those are what the FTA uses- if not, then they did it the hard way. -- Jawaid Bazyar | "I'm sure K&R have never heard of Mike." Senior/Computer Engineering | bazyar@cs.uiuc.edu | "That's okay. I'm sure Mike's never heard of K&R". Apple II Forever! | (discussion about Orca/C)