On Sat, Jul 2, 2016 at 10:15 PM, Peter Coghlan <[email protected]> wrote:
> >> Is the capacity of the diskette 800K? or is that merely the name of the >> type of the diskette, with an actual capacity of somewhere between 640K and >> 800K? >> >> If the actual capacity is 800K, with MFM, then it would probably be 80 >> track, double sided, with either 10 512 byte sectors or 5 1024 byte sectors >> per track. (can't get up to 800K with "normal" WD style MFM with 256 bytes >> per sector, and 512 byte sectors are a little tight) >> >> > The original ADFS had 16 sectors of 256 bytes per track. However, it > appears > that more recent ADFS formats use 5 sectors of 1024 bytes. There are more > details here: > > http://mdfs.net/Docs/Comp/Disk/Format/Formats > > Regards, > Peter Coghlan > > Thanks everyone. All working now - there were two issues at play. 1) Wrong settings for DTC. Used the linked-to document to change to 1024Byte sectors, tracks 0-79 and sectors 0-5. I record the stream file of flux transitions as before (a preference in any event) and when I process it with the aforementioned settings I get an 800KB .adl image file. This mounts up in an emulator very nicely: https://www.dropbox.com/s/hjgz3416htlryrm/Screen%20Shot%202016-07-03%20at%2012.19.15.png?dl=0 2) The initial disc I used was an original disk for a game - SWIV. I suspect that it either uses some interesting copy protection mechanism or the media is faulty. The above method works for 9/10 discs but not the one I originally selected for testing. Lesson learned - use known good media or a selection of suspect ones. -Austin.
