Roland D20 Non standard floppy drive

HxC Floppy Emulator Roland Samplers/Keyboards support
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Roland D20 Non standard floppy drive

Post by kolleykibber » Tue Mar 19, 2019 12:41 pm

I was wondering if it's possible to use HxC on a non standard floppy interface. The venerable (1988) Roland D20 uses an interface I can't find else where. Instead of step or direction the Phase magnet signals (Pha, phb, phc phd) are sent directly from the controller chip, which is an unknown MOERO U78152-A (M60012-0110) then another chip is used to maybe amplify these signals to drive the stepper motor. There is no track 0 pin. I imagine the floppy controller uses the phase pins to return the head.

Amongst other strangeness. The floppy controller directly controls the in use LED.

Full details of the pins and schematics are available here (page 13):- ... -Notes.pdf

Would it be possible to translate the phase signals to standard step/dir signals to feed into HxC?


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Re: Roland D20 Non standard floppy drive

Post by Jeff » Tue Mar 19, 2019 10:09 pm

Interesting, this look similar, if not equal, to the Apple II floppy interface.
I have done a custom firmware several years ago to support these kind of floppy interface :
But this still very "proof of concept"/hacky...

The disk format appears to be different too.

But i will study the question :D.

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Re: Roland D20 Non standard floppy drive

Post by Jub » Sat Nov 02, 2019 9:24 am

Interesting stuff.
My D20 drive seems to be dead, and it would be nice if I could replace it with a HxC :D

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