Least PC-Compatible MS-DOS machines?

On 06/03/2014 11:44 AM, Tony Duell wrote: It's a matter of perspective, I suppose. I was looking at it from a conventional viewpoint--with the disk turning at a constant speed, which is the way most people view them today. Saying "variable speed spindle" doesn't convey quite the same level of arcaneness to me. At least one "1.2M" PC drive (Weltech) used a 250Kbps bitrate and spun the media at 180 RPM for high denisty and 300 RPM for double-density. The drives did not work very well. We still have a holdover of this on 3.5" USB drives--if you insert a 1.3MB (Japanese DOS) floppy, the drive will automatically change from 300 to 360 RPM. Let's not forget the Lisa "Twiggy" disks in this category, also. Listening to the drive speed change as the heads moved in and out was pretty annoying. I recall my reaction when I read about Victor's rather arcane scheme for their recording in one of the electronics trade mags. Plain GCR would have gotten them over 1MB on a double-sided 96 tpi DSDD floppy. We figured it must have been hangover from the Commodore days. I was surprised that they didn't try to fit a 6502 in as a disk controller. Another memory of Victor is that they sued anyone they could who used the Victor name, including an electronics dealer who'd been in business with the same name for 30 years. A rather ugly business. --Chuck