More than 2 FDDs on a PC (was Archiving software)

Actually, I was full of excrement - Once I dug back into the guts of the floppy code to look at making these changes, I discovered that I had already put in my own interrupt handler some time ago... So I don't use BIOS of anything! (I did use the BIOS interrupt handler in the early stages) Also from digging into my sources, I discovered that the docs I have describing Bit-3 are wrong as the sense of the bit is inverted to what is shown - this is consistant with your description above. If your PC is fast enough, ImageDisk will read the track in a single revolution, however it will take additional revolutions for re-analysis when the track format changes. Also, for tightly spaced sectors, it may not be able to read them fast enough, which results in one revolution per sector. A useful trick in this case is to read them with a different interleave than the disk is physically formatted - for example, if the disks are formatted 1:1, then reading them 2:1 will allow one extra sector to pass between reads (two revolutions total) - The resulting image will indicate 2:1 interleave (however the sector numbering will be correct for 2:1) and can be used "as is", or you can use IMDU to re-interleave it back to 1:1 - but these steps are only necessary if you are reading a lot of disks and your PC can't keep up at 1:1 interleave. Regards, Dave -- dave04a (at) Dave Dunfield dunfield (dot) Firmware development services & tools: www.dunfield.com com Collector of vintage computing equipment: http://www.parse.com/~ddunfield/museum/index.html