[Coco] Disto Super Controller problem

[Gene Heskett]

On Saturday 29 March 2008, Roger Taylor wrote:
>I'm not sure if this is my controller at fault or my drive, but when
>I DSKINI or write anything to a disk, the CoCo doesn't complain, but
>when you read the directory back, nothing has changed.  A DSKINI
>format will step through the tracks until it goes to verify then an IO
> error.
>
>I've tried to DSKINI a known good disk with CoCo files on it, and
>after the DSKINI appears to write then fails, you can type DIR and
>the files are still there.
>
>Anybody know what's going on?
>
It sounds like you are not actually writing to the disk, Roger.  There is I 
believe a write enable signal that turns on the drives write circuitry, and 
it may not be enabled.  Chip failure or drive failure can be determined by 
looking at the pin on the interface with a scope and seeing it if goes to the 
other logic state during a DSKINI operation.  Since the also writes the 
intersector data, the signal should be true at whatever logic level enables 
the write, and go to the other logic level when the verify phase starts.  If 
it does, drive problem, if it doesn't, controller problem & start chasing it 
back through the buffers to the src, which I believe is the 1773.  If nothing 
there, double check that the coco's write is getting to it.  Stuck bits in a 
read scan might be enlightening too.

>Also, what kinds of devices are there, or can be made, to work with
>the MEB connector on the side?  It sure does look like an IDE connector.  :)

Its not, but all the other stuff on the 4n1 cards run on that bus, scsi, 
parport, rs232 & the realtime clock, so its a fairly complete bus, but IDE 
its not.

-- 
Cheers, Gene
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