alexh wrote:Looks interesting. How does the device stack up against Kryoflux? I'm interested to see one being used.
I am modifying the prototype (should be ready today) so it can read SuperCard Pro raw csp format.
DrCoolZic wrote:Fuzzy (aka weak) bits requires a least 2 rev
JimDrew wrote:DrCoolZic wrote:Fuzzy (aka weak) bits requires a least 2 rev
No... that's a myth. If that were the case, then the image file I sent you would not create a working disk, and it certainly does. There are ways to determine where weak bits are located without having to read the disk multiple times. Also keep in mind that reading and writing of weakbits is *extremely* drive dependent. Some drives will not read (or write) weakbits at all.
Most all disk dumps with SuperCard Pro only need a single revolution, weakbits or not. The ONLY time you need a multi-rev dump is when the track does not start/stop on the index pulse. In these cases, we need 2 revolutions. The writing portion is then responsible for determining where the write splice is located (somewhere in the 2nd revolution) and writing out the disk as one full revolution + a partial revolution so that the data overlaps perfectly and shuts off the writing. There is no need to look at disk structures, decode anything, etc. The only thing you have to figure out is exactly where the writing was turned off on the original. Numerous write splices can occur on a disk and I see this quite often (especially with ST disks apparently). As long as you are not shutting off the write in the middle of a sector or some other valid data, you can shut it off anywhere. I locate a valid write splice and make the copy as accurate as the drive speed variation allows.
Thanks for the disk image file format info!! I figured that .ST files were just straight sectors.
DrCoolZic wrote:Detecting fuzzy bits (as described in patent 4849836) requires 2 or more revolutions by definition (see below)
JimDrew wrote:I had an idea I thought I would run by everyone... would anyone be interested in being able to read and write real ST disks with an emulator? I could program a complete WD1772 FDC emulation into the SuperCard Pro hardware and emulators could pass the FDC commands just like the ST does. I dont know who does the development of the various emulators, but if this is of interest it's something I can look at adding.
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