On 01/24/2018 02:35 PM, Glen Slick via cctalk wrote: > On Wed, Jan 24, 2018 at 9:45 AM, Fred Cisin via cctalk > <cctalk@classiccmp.org> wrote: >> >> Does ImageDisk or Teledisk support it? >> If so, then with the ED controller and one of these drives from Chuck, you >> could image things such as the "4 Meg" floppies from NeXT. (4M is the >> UNFORMATTED capacity of the 2.8M disk, and NeXT marketing thought that "4M" >> sounded better than the "2.8M" formatted capacity) >> > > The ImageDisk 1.18 source code is available to inspect to answer the question. > > If there is something special that software needs to do to select a > 1000K bps data rate I don't see anything in the ImageDisk code which > does that. What does software need to do to select the 1000K bps data > rate for 2.8M mode?
Yes, the intel 82077 datasheet should tell you all you need. One aspect is that if you're operating in 1Mb/sec mode, you need to set perpendicular mode in addition to setting the 1M data rate, so not altogether straightforward. --Chuck
