[Coco] Another drive question

[John E. Malmberg]

Roger Taylor wrote:
> 
> I also thought the low-level sector codes that surround the actual data 
> has to be specific to the system or controller reading the disk?

No.

The device driver decides what low-level sector codes are acceptable to it.

IBM set the standard for 512 byte floppy media, and every one follows that.

In the Tandy field, the only oddball for floppy formats is the TRS-80 
Model 1/III/IV directory track.  All other sectors can be read.
IIRC: They set the Deleted Address Mark on the sectors of that track, so 
the PC bios thinks the sectors are bad and will not return the data read 
up to the application.


Flex-09 has the first track in single density, which is another small 
stumbling block.  And the only way I see around that is to have the COCO 
  based program copy it to a double density disk.


And of course I would use a freshly degaused and formatted floppy for 
the transfer.  Since the host system can format the floppy, only the 512 
byte sector read and write lowlevel functions would have to be coded.

-John
wb8tyw at qsl.net
Personal Opinion Only