7 Dec
2009
7 Dec
'09
10:53 a.m.
Chuck Guzis wrote:
On a diskette produced on a write-the-entire-track
formatter, such as
a Formaster duplicator, everything returned by a Read Track looks
great, as there are no write splices. However, a floppy produced
with a disk copy program, each sector is written individually, with
accompanying write splices, so even if you manage to create a format
with HGC in the right place (hint: format 128-byte sectors with
different length codes in their headers), it stands a good chance of
not working.
Interesting way to do copy-protection... Yet another format that can't
be (easily) created without a track-writer. Or an Amiga.
The Amiga Copylock system is pretty unusual too -- that varies the
bit-rate mid-track (by +/- 5% or so if memory serves). For that, even a
trackwriter isn't enough unless it allows you to change the bit rate.
(Reading FM on modern PCs)
Depends on the modern PC. Some modern PCs do better
than vintage
ones.
In my experience, the current generation of PCs can't handle FM at all.
My 386 (with ISA floppy controller) is scarcely any better.
The last time I wanted an image of a BBC Micro floppy, I ended up
streaming it across the RS423 port at 9600bps. Ugh. Not fun.
--
Phil.
classiccmp at philpem.me.uk
http://www.philpem.me.uk/