LisaList2

Quote from: AlexTheCat123 on July 28, 2026, 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

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!

That's my plan for when I get a round tuit --- a nice acrylic sandwich.

I don't have a 3D printer, so went with a simple clear acrylic panel that uses the board's four holes. Seems to work pretty well.

Bambu Lab P1S, with Bambu Labs Grey PLA filament

Quote from: joeventura on July 24, 2026, 08:43:14 AMCame out fabulous!

It appears to be a beautifully clean print! I'm curious to know what type of printer and filament you used.

Came out fabulous!

Bravo!  Printing it now!

Quote from: ried on July 22, 2026, 09:49:56 PMCheck out what Alex made! 

You're giving me too much credit; Claude did most of the work here! I intended this to be a teaching aid that would help me learn LOS app development and I wasn't even planning on making it public because of all the hate that using AI can get you nowadays, but Adrian liked it so much after I showed it to him that I decided to release it after all. Hopefully people enjoy it!

Check out what Alex made! 

https://www.youtube.com/watch?v=0SnadQGIZtI