All: I?ve been busy lately rebuilding the floppy system on my IMSAI. I scrapped the Frugal Floppy 8? in favor of a CompuPro Disk 1 using 5.25? disks to emulate 8?. This has been a long running project, but with the assistance from someone on comp.os.cpm who went through the exact same process with nearly the same hardware, I?ve been able to create a brand new CP/M 2.2 master disk. Yeah! Anyway, one of the issues I have with the Teac FD-55GFR (1.2mb high-density; no schematic) drives I?m using is that the motor runs all of the time (just like an 8? drive) but these late-model Teac drives don?t have head relays, so the heads are engaged all of the time. I?m looking for some advice/whatever on engaging the motor when needed. The Disk 1 is based on an 8272 controller chip and it has a HDL (head_load) signal which, through jumpers can be made to appear on the *MOTOR signal pin of the standard IBM floppy disk interface. I tested the HDL signal and it activates at the right time, so its following the 8? sequence, but the pulse width leads me to believe that it?s too short to let the motor spin-up and go ?ready?. There is a way to control this with software...and I may go that route anyway...but has anyone done this sort of thing ? used a 5.25? HD drive to simulate an 8? drive and if so, which drives did you use? Any input appreciated. Thanks. Rich -- Rich Cini Collector of Classic Computers Build Master and lead engineer, Altair32 Emulator http://www.altair32.com http://highgate.comm.sfu.ca/~rcini/classiccmp