[Coco] [Color Computer] [coco] SCSI trouble

[George's Coco Address]

From: "Manney"
Sent: Thursday, May 24, 2007 5:24 PM
Subject: Re: [Coco] [Color Computer] [coco] SCSI trouble


> George's Coco Address wrote:
>>>> ----- Original Message ----- From: "George's Coco Address"
>>>>
>>>>> I use a Ken-Ton SCSI interface on one of my coco3 machines under OS9
>>>>> L2. In
>>>>> a recent attempt to backup the hard drive (ST138N) to another, 
>>>>> external
>>>>> ST138N, I discovered that I could not access the external drive and 
>>>>> the
>>>>> internal drive is being accessed as both /h0 and /h1.
>>>>> This system used to work, but it was a long time ago since I did a
>>>>> backup.
>>>>>
>>>>> Any suggestions as to what may cause this problem?
>>>>>
>>> From: "Joel Ewy"
>>> SCSI bus termination?
>>>
>>> JCE
>>
>> Yeah, they are there.
>
> I remember with the older Macs that you had to have, for lack of memory, a 
> different number for each drive. Otherwise, you would run in to big 
> problems. (Like losing the data on one of the drives, etc.)
>
> Any chance you could be running in to that? Could someone come in and help 
> with my memory loss here? :)
>
> -M.

 I'm almost certain that having two drives with the same ID would cause 
problems. However, as I said above, the primary drive will respond to any 
drive number called upon. So it can't be used on a two drive system.
 In later posts, I told of the results of further investigating and 
discovered that the backup drive doesn't even work. I even made a new boot 
disk, tested the primary drive and proved that it is defective. The primary 
drive still responds to any drive number I request. It was working fine when 
by itself in the system.

DOH

 Now that I think of it, it is possible that your suggestion may actually be 
associated with the reason the secondary drive failed to work. Since the 
primary drive responds to any drive number, it could have caused the failure 
of the secondary drive when I connected it and tried to use it. After that, 
I had to go through the steps to isolate the problem. I hadn't thought of 
this problem doing exactly what you were talking about. The jumpers were 
correct, terminators in place, good power... I didn't SNAP to the idea you 
suggested until now.

Coool...

 Now I'm pretty sure a reformat will work on the secondary drive if it is in 
the system by itself.... for what good it will do. I had two of the things 
for the purpose of backups. So, it's back to using floppies to make backups. 
I might retire the defective drive, or change a chip that is near the jumper 
pins. I haven't looked up the number, but it does look as if it is wired to 
the jumpers.


George