Roland D20 Non standard floppy drive

[kolleykibber]

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):-

https://www.synthxl.com/wp-content/uplo ... -Notes.pdf

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

Thanks

[Jeff]

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 : https://www.youtube.com/watch?v=MaR9noqb0JE
But this still very "proof of concept"/hacky...

The disk format appears to be different too.

But i will study the question .

[Jub]

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

[Jub]

My floppy was dead because of a broken belt.
Found a new one one ebay, and it is back online.

But, it was the opportunity to confirm that the Roland D20 floppy interface has nothing to do with other floppys I saw before (PC/Atari/Amstrad computers, Akai samplers...)

IMG_9956.JPG (184.1 KiB) Viewed 26906 times

[Jeff]

mhh interesting !

[Jub]

I found out the service manual (here) and here is the wiring of the floppy

Could it help to fit a standard floppy, and thus a HxC drive into the D20 ?

[Jeff]

Hello,

FYI the HxC firmware for Gotek now support the Apple Disk II emulation :

https://hxc2001.com/docs/gotek-floppy-e ... apple.html

So the firmware "may" work with the Roland D20. Let me know if you want to test it.

[Jefro]

I just signed up to say that I'm volunteering to be the guinea pig, to test this in a Roland D-20. I'm fairly certain I was the first to put one in a Yamaha DX7IIFD as well.

[Jefro]

I got my hands on a D20. I'm waiting on a couple parts, but should know if this is gonna work sometime next week.

[Jefro]

Would anyone mind doing a sanity check on my notes? I compared the image above from the roland D20 service manual, and the Apple drive notes, but the indicators aren't 1:1. I did some guesswork to try to determine the pins that didn't match.

Edit: I dug into this a bit more and made some changes. There's 1 pin I'm really uncertain about CN8 Pin 7 on the D20.

CN7 pin (8) [DISK] =====> [DS0] Gotek DB 19 pin (10)
CN7 pin (7) [DS] =====> [/SIDE1] Gotek DB 19 pin (32)
CN7 pin (6) [PROT] =====> [/WPT] Gotek DB 19 pin (28)
CN7 pin (5) [PHA] =====> Gotek UART J4
CN7 pin (4) [PHB] =====> Gotek UART J3
CN7 pin (3) [PHC] =====> [/DIR] Gotek DB 19 pin (18)
CN7 pin (2) [PHD] =====> [/STEP] Gotek DB 19 pin (20)
CN7 pin (1) [MTR] =====> [/MOTEB] Gotek DB 19 pin (16)

CN8 pin (7) [WCC] =====> Gotek DB 19 pin ()
CN8 pin (6) [WD] =====> [/WDATA] Gotek DB 19 pin (22)
CN8 pin (5) [WG] =====> [/WGATE] Gotek DB 19 pin (24)
CN8 pin (4) [FRD] =====> [/RDATA] Gotek DB 19 pin (30)
CN8 pin (3) [5v] =====> Gotek Power (1)
CN8 pin (2) [G] =====> Gotek Power (2)
CN8 pin (1) [G] =====> Gotek Power (3)

Thanks for any help you can provide.

[Jeff]

Would anyone mind doing a sanity check on my notes? I compared the image above from the roland D20 service manual, and the Apple drive notes, but the indicators aren't 1:1. I did some guesswork to try to determine the pins that didn't match.

Edit: I dug into this a bit more and made some changes. There's 1 pin I'm really uncertain about CN8 Pin 7 on the D20.

CN7 pin (8) [DISK] =====> [DS0] Gotek DB 19 pin (10)
CN7 pin (7) [DS] =====> [/SIDE1] Gotek DB 19 pin (32)
CN7 pin (6) [PROT] =====> [/WPT] Gotek DB 19 pin (28)
CN7 pin (5) [PHA] =====> Gotek UART J4
CN7 pin (4) [PHB] =====> Gotek UART J3
CN7 pin (3) [PHC] =====> [/DIR] Gotek DB 19 pin (18)
CN7 pin (2) [PHD] =====> [/STEP] Gotek DB 19 pin (20)
CN7 pin (1) [MTR] =====> [/MOTEB] Gotek DB 19 pin (16)

CN8 pin (7) [WCC] =====> Gotek DB 19 pin ()
CN8 pin (6) [WD] =====> [/WDATA] Gotek DB 19 pin (22)
CN8 pin (5) [WG] =====> [/WGATE] Gotek DB 19 pin (24)
CN8 pin (4) [FRD] =====> [/RDATA] Gotek DB 19 pin (30)
CN8 pin (3) [5v] =====> Gotek Power (1)
CN8 pin (2) [G] =====> Gotek Power (2)
CN8 pin (1) [G] =====> Gotek Power (3)

Thanks for any help you can provide.

This seems to be a mix up between the apple ii and quickdisk interface. some firmware changes are needed. Can you check the WD,WG,FRD, MTR, PROT, DS signals polarity ?

[Jefro]

This seems to be a mix up between the apple ii and quickdisk interface. some firmware changes are needed. Can you check the WD,WG,FRD, MTR, PROT, DS signals polarity ?

Thanks for getting back to me. That actually seems to make a lot of sense, given Quickdisk drives were in a lot of word processors, and Brother, who made the drive in the D20 also made a ton of word processors.

..anyway, I'll get back to you this evening with those details.

[Jefro]

I did a quick probe of the pins with a multi-meter and this is what I see (updated after rechecking these):

CN7 pin (8) [DISK] +5v
CN7 pin (7) [DS] +.012v
CN7 pin (6) [PROT] +5v
CN7 pin (5) [PHA] +.013v
CN7 pin (4) [PHB] +.012v
CN7 pin (3) [PHC] +.012v
CN7 pin (2) [PHD] +.012v
CN7 pin (1) [MTR] +5v

CN8 pin (7) [WCC] +.001v
CN8 pin (6) [WD] +5v
CN8 pin (5) [WG] +5v
CN8 pin (4) [FRD] +5v