On 08/11/2017 10:58 AM, Marvin Johnston via cctalk wrote: > I seem to recall this topic has been brought up a couple of times > over the past 20 years or so that ClassicCmp has been in existance, > but I can't find the info. And technology has advanced :). > > I have probably at least 10,000 floppy disks of many flavors > (formats, hard sector, soft sector, various TPI and Tracks/disk, > 3.5"/5.25?/8", etc.) My most pressing/interesting issue is both > Polymorphic and Lobo Drives/Systems 5.25" and 8" disks.
I don't think a solution exists to make real copies of *any arbitrary* floppy. Even the idea of two drives powered off the same motor, aligning index holes, etc. will not work. The reason is quite simple--on a low level, what you read from a floppy is not what was written. There are issues that crop up during writing a floppy, such as bit shift and crowding that must be compensated for--and it's very, very difficult to do this on a "blind" basis without knowing something about the format. This, after all, is what "write precompensation" is all about--an intentional distortion of the write process to ensure that reading looks more or less normal. And this isn't dealing with various copy-protection schemes, special-purpose replacement drive electronics boards (they exist) and varying track densities (48, 96, 100, 135, 67.5 tpi) as well as the real oddball stuff, such as Kodak/Drivetec floppies. I recently ran into a floppy drive used on a CNC controller that has an utterly non-standard track spacing--the manufacturer included in their PLC solely for reading a disk of proprietary software--i.e. the PLC has *two* floppy drives; one standard and the other just for those floppies. I use a Catweasel to image my floppies--it does the job well, but so will any decent modern microcontroller with a timer "capture" function. --Chuck
