[Coco] DriveWire success... and some questions

[Mike Pepe]

Joel,

There isn't much lower level you can get than the raw sector reads that the WD1773 does by default under the command of BASIC.

Analysis of the errors given by the particular bad sector may give some indication of the nature of the problem, as any error returned by BASIC is just ?IO ERROR when there are in reality several different types of errors that can be encountered during the read operation. The folks here can probably go into further detail, but the WD1773 chip datasheet may be worth looking at.

I would also try reading the disk in several different drives. Here is one case where having access to an 80 track drive may be helpful as the smaller head pitch may be able to read a part of the wider original track that's still good.


> -----Original Message-----
> From: coco-bounces at maltedmedia.com [mailto:coco-
> bounces at maltedmedia.com] On Behalf Of Joel DeYoung
> Sent: Monday, December 28, 2009 1:01 PM
> To: CoCoList for Color Computer Enthusiasts
> Subject: [Coco] DriveWire success... and some questions
> 
> I received my DriveWire and HDB-DOS chip from Cloud 9 a few days ago
> and am
> happy to report I was able to use them successfully to hook up my CoCo
> 3 to
> my Mac via USB.
> 
> My CoCo stuff had been packed away for many years and I didn't think it
> was
> realistic at all to expect the floppies to read.  But most of them did
> so I
> got hooked up with DriveWire to be able to back everything up.  Seeing
> all
> the old stuff I did so many years ago brought back a lot of great
> memories.
> I work in the video game business now and started out as a programmer.
> Working on the CoCo as a kid was what got me started with computers so
> this
> stuff is pretty important to me (even if my BASIC code looks pretty
> atrocious with the benefit of hindsight!).
> 
> Thanks to Mark and Boisy at Cloud 9 for creating these products,
> keeping
> things going on the CoCo after all these years!  Kudos!
> 
> I have a couple of questions about reading floppies.  A couple of them
> have
> IO errors.  It seems the BACKUP command won't work if any IO error is
> encountered.  So in one case the directory was intact so I was able to
> copy
> files one at a time, and only miss the ones that are corrupt or
> unreadable.
> My question is are there any programs which attempt low level reads to
> recover data from corrupt floppies?
> 
> Second, I have a few commercial floppies which defy using BACKUP.  I
> think
> this may be due to come copy protection scheme since the discs read
> just
> fine.  The discs in question are Bugs II by Four Star Software and
> Gantelet
> II by Diecom Products.  Anyone have experience with this?
> 
> I'm happy to be back using my CoCos!
> 
> Cheers,
> Joel
> 
> --
> Coco mailing list
> Coco at maltedmedia.com
> http://five.pairlist.net/mailman/listinfo/coco