Creating new CP/M disks - Progress on IMSAI

I was trying to oversimplify a bit on my reply; Teac drives across any single product line have a tremendous potential for variability. The last thing in the world I wanted was for someone to hunt down a set of FD-55GFR drives and report back that they didn't work. The same variability is present in 3.5" Teac drives--the 235HFs come in many varieties; some offer many options; others offer next to none. Undocumented jumpers and pads on drive PCBs are even wilder in assortment and presence/absence. I've had pretty good luck with Mitsubishi and NEC floppy drives manufactured for the Japanese market (PC9801-style systems). As the floppy format is based on an 8" model and doesn't change much across physical formats, the drives themselves tend to behave when pressed into use in 8" applications. They can be tough to find on this side of the Pacific, however. Generally, the later a drive is manufactured, the more "smarts" are used in its drive control logic--and the less it will be suited for non-PC use. I was surprised to find that there's a Toshiba 3.5" floppy (ca. 1996) that senses the data rate on HD diskettes and automatically changes its spindle speed. You can read, write and format 1440 KB on it and read and write 1232 KB, much like many USB and IDE floppy drives. The idea probably was that there were still a lot of DOS-V format floppies hanging around Japan and wouldn't it be nice to be able to read and write them on a "generic" PC... Heaven only knows what the drive would do with some nonstandard data rate or modulation. Hope this helps, Chuck