LisaList2

I'm working on the floppy emulator for LisaFPGA, and I'm confused about how Twiggy drives clamp disks. There doesn't seem to be a motor or solenoid or anything that clamps down on them, and no way to command the drive to clamp or unclamp using a dedicated signal, but it doesn't appear to be some sort of automatic spring-loaded trigger mechanism like the Sony drives either. Is it some sort of system where seeking the heads out of an idle position engages the clamp and then seeking back to that position disengages it and ejects the disk? And if so, where's that position relative to the normal range of the heads?

I think I have all of the other info I need to emulate the Twiggy (they're remarkably similar to 400K/800K drives, just with different disk geometry and a different (and simpler) physical interface, but this is the once piece that I'm missing!

Quote from: AlexTheCat123 on Yesterday at 06:36:53 PMhow Twiggy drives clamp disks... Is it some sort of system where seeking the heads out of an idle position engages the clamp and then seeking back to that position disengages it and ejects the disk? And if so, where's that position relative to the normal range of the heads?

Yes, exactly. When the carriage is moved to the rear of the drive, the disk is unclamped. When the disk is actually released, the "disk-in-place" sensor is un-triggered, so the FDC knows to stop moving the carriage.

https://flickr.com/photos/114907644@N04/12035889576/in/album-72157639938971635

Thanks, that helps a lot!