Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!usc!samsung!caen!acc.flint.umich.edu!jal From: jal@acc.flint.umich.edu (John Lauro) Newsgroups: comp.os.os9 Subject: Re: adding as disk drive to COCO3 Keywords: disk drive, high density, os9 Message-ID: <1991Jan3.011714.698@engin.umich.edu> Date: 3 Jan 91 01:17:14 GMT References: Sender: news@engin.umich.edu (CAEN Netnews) Distribution: usa Organization: University of Michigan - Flint Lines: 31 In article roccella@pilot.njin.net (Matthew Roccella) writes: > > 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! I doubt the CoCo can handle a 1.2 Meg drive as is. A high density drive requires a different controller chip, which is why you can't put a 1.2 meg drive in a PC without also replacing the controller. (286 AT class machines come with that type of controller.) You should be able to connect a 720k drive with little trouble. I don't know if a high density drive can act as a 720k drive or not. (Who knows, maybe the CoCo 3 controller does suppoer high density?) Are you sure you have the jumpers on the drive right? Most drives as bought these days come ready for PC compatables, which have the jumpers set differently then you would use for a cable with traces cut. (Personally I prefer setting the drive select jumpers to messing up a straight through cable.) Another thing to check is if you have one and only one terminator and it's on the correct drive. - John