[Coco] Disk Basic and 512 byte block floppies.
flexser at fiu.edu
Sat Jan 17 02:38:18 EST 2004
On Fri, 16 Jan 2004, (tim lindner) wrote:
> Interesting experiement.
> The size of each sector is written to the disk. Disk BASIC expects all
> the sectors to be 256 bytes, it doesn't check. It create 256 byte blocks
> of RAM to read to and from these sectors.
> If the sector is larger, then the RAM buffer will overflow. On a read
> sector command you will overwrite whatever is past the sector buffer in
> RAM. The could be dangerous.
> On a write sector command you will write whatever data is after the
> buffer to the larger sector.
Weird sized sectors (along with weird sector numbers, etc.) have been a
popular device used in CoCo copy protection schemes. Basic's BACKUP
command won't work properly with such disks.
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