1.2M HD / 300kbps / single-density

Yes - Yes --- didn't anyone read my next posting made within about 10 mins of the first one where I indicated this was a typo (yeah, I know.. people answer in the order they read them). I agree completely, which is why I always use the proper drive type for the disk format I am reading or writing ... This is why I have never noticed this before... In my original post, I indicated I was moding a drive to do double duty as a 80 track HD and a 80 track DD drive - this should be OK, as the data rates, number of tracks correctly match the disk format in both cases (with the mod to switch the drive down to 300rpm for DD). But ... I get correspondance from people trying to use ImageDisk to make specific disks, and they often don't have all of the various drive types. Making 5.25" disks in an HD drive is VERY common - Many people don't have spare 5.25" drives kicking around, and when they finally find one, it's in sombodies old 386 and conforms to "AT standards" (ie: 1.2M HD drive fixed at 360rpm). At appears that some systems do support SD at 300kbps (150kbps data rate) and some don't. I think it might be time to begin building a database of exactly what can be done with various mainboards and controllers - When I get some spare time, I will put together a utility to test the various modes with the various drive types and make it available on my site so that these things can be easily characterised - as I've recently learned "it does single-density" isn't a complete answer. Dave -- dave06a (at) Dave Dunfield dunfield (dot) Firmware development services & tools: www.dunfield.com com Collector of vintage computing equipment: http://www.classiccmp.org/dunfield/index.html