[comp.sys.mac.programmer] Accessing low-level disk information?

aries@rhi.hi.is (Reynir Hugason) (10/09/90)

Hi,

   I'm wondering if I can access the address mark information contained on
a floppy disk? I need to read the address mark of certain sectors and possibly
rewrite it. If anyone has done this, and is willing to share his/hers
experience, I assure you I'll listen with open eyes.

Thanks in advance for any info.

Mimir (aries@rhi.hi.is) - Aries, Inc.

stevec@Apple.COM (Steve Christensen) (10/09/90)

In article <2261@krafla.rhi.hi.is> aries@rhi.hi.is (Reynir Hugason) writes:
>
>   I'm wondering if I can access the address mark information contained on
>a floppy disk? I need to read the address mark of certain sectors and possibly
>rewrite it. If anyone has done this, and is willing to share his/hers
>experience, I assure you I'll listen with open eyes.

Don't do it.  Why, you ask?  Well, because you'd need to talk directly to the
floppy disk controller, which is slightly different or unavailable on existing
Macs, and could be completely different on Macs-to-be.  This is especially
important if you want to release this program to the real world.

The floppy disk driver supports reading address marks, but it has no facility
for writing them, since that's only done at format time.  That being the case,
you'd have to try to run the disk drives yourself, which is kind of a pain
given the various hardware configurations.

steve
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