Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!tut.cis.ohio-state.edu!n8emr!bluemoon!a.dent From: a.dent@bluemoon.uucp (Bryan Hannahs) Newsgroups: comp.os.os9 Subject: Re: adding as disk drive to COCO3 Keywords: disk drive, high density, os9 Message-ID: Date: 7 Jan 91 16:28:14 GMT References: Sender: bbs@bluemoon.UUCP Organization: Blue Moon BBS ((614) 868-9980/2/4) Lines: 43 roccella@pilot.njin.net (Matthew Roccella) writes: > > Hello, > I am trying to add a 1.2 Meg 5.25" disk drive to my COCO3. But > I keep running into trouble. I made up a new drive cable, cut all the > traces from my /D0 drive, accept the one that designates the drive as > /d0, and I made a new OS-9 boot disk with the d1_80dd descripter. > My trouble is that the system keeps giving me CRC errors and > BAD SYSTEM TRACK errors. I cannot read, write, or format any disks in > this new drive at all. My /d0 drive works fine. > Doesn't the COCO3 take standard IBM type off disk drives? What > kind of drive is compatible with the COCO3 and where can I get one at > a good price? If anyone has added a disk drive to their COCO, please > let me know what you did and how things have turned out. I'm racking > my head as what to do next! > Thank you, > Matthew Roccella Hmm...well, first, if you got the motor running and the drive selected with your cable and such, I'd like to know what the changes were. I've got a 1.2meg I've been trying to use on my XT clone. It selects, but the motor won't run. Same thing happens when I try it on my CoCo. Does the drive work if you use a 360K (40 trk, DSDD) descriptor? If so, then it MUST be your descriptor. To the best of my knowledge, the CoCo controller only formats at double-density. This will allow you to get 720K (80 trk, DSDD) if all goes well. You won't be able to get the full 1.2meg as that requires more sectors per track than the CoCo can handle. The thing that puzzles me is that my XT's controller is SUPPOSED to be able to handle the 1.2meg AT drives. I think maybe I just have a jumpering problem, but I may need to twist the cable too. If it's just a matter of the motor select pin being in a different place, I'd try cutting the trace on the drive and moving it. I already have 3 360K drives for the CoCo, plus one in the XT, but it would be kinda nice to put a 720 on the CoCo even if I can't get it to work on the XT. 'Course, there should be no problem putting a 720K 3.5" drive on the CoCo, but I don't have any of them lyin' around at the moment... Bryan Hannahs (aka Arthur Dent) (BTW, please leave replies to me in comp.sys.tandy or comp.sys.m6809 as I don't generally read os9 stuff)