Re: Nibble Images ...

[Rubywand <rubywand@swbell.net>]

Vincent Joguin writes ...
> 
 ....

> Unfortunately, when the controller is fired reading a sector, it can't
> be stopped. If it's not serviced in time, it will return an error
> (with a "not serviced in time" flag set) and will finish the read
> command.
> 
> Anyway, if you've got a PC 5.25" drive, I suppose it's not a big issue
> to also have a 3.5" drive in the same computer, but I agree it would
> have been cooler to be able to use just one drive.

     True. Practically any PC with a 5.25" drive is going to have two floppy
drives.

> 
> Lastly, in fact, it's partially possible to read a track (even an
> Apple 2 track) with a single drive. Read the 1DISKDRV.TXT file in the
> DOCS\TECH subdirectory of the archive which explains (for the Amiga,
> but Apple 2 is the same in this case) how little room on a track is
> necessary to be able to read the rest back. Again, unfortunately, the
> Apple 2 drive (as well as most drives of the time, except on IBM
> machines) doesn't take the index signal into account (well, there may
> even not be an index signal at all with the disk II, but I don't know
> it enough to be sure), so the "formatting technique" explained cannot
> work reliably without killing one or two sectors randomly before
> getting a chance to read them...
 ....

     Yes; with a Disk II diskette you would have no index signal. 



Rubywand