Yamaha W7 and Gotek

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xuulan
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Yamaha W7 and Gotek

Post by xuulan » Sun Jan 20, 2019 10:01 pm

Hello all,

I'm working on getting a HxC flashed Gotek drive to work in a Yamaha W7. I've updated to the latest beta software (3.1.34.2).

I've made an adapter board from the 24-pin FFC cable to 34 pin IDC (schematic attached). I can read and write disks, however there are two issues:

-cannot format disks (stuck at 00%)
-cannot switch disks unless it is changed on the Gotek then the whole machine is power cycled.

I believe that the issue is related to the Disk Change command. In factory test mode, neither the disk change nor the format tests work. I've seen a few solutions on the Yamaha forums (using READY for the Disk Change command, and then using Motor On for Ready), but this didn't work for the Gotek. From what I've read, the W7 uses MSX floppy drives, however setting the second menu to MSX (instead of generic Shugart) didn't help.

I suppose this is a workable situation since both reading and writing is working, but it presents issues with spanned disks (not sure if the W7 uses them, but the SY85 and other Yamaha equipment does)
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Jeff
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Re: Yamaha W7 and Gotek

Post by Jeff » Mon Jan 21, 2019 8:32 am

Have you tried to change the floppy interface mode ? It is maybe in PC interface mode. I believe that these Yamaha interface are in Shugart mode ?

xuulan
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Re: Yamaha W7 and Gotek

Post by xuulan » Mon Jan 21, 2019 10:39 pm

Hi Jeff,

The interface was set to Generic Shugart. I tried MSX and a few others, but it didn't improve the situation.

The adapter board was designed to accommodate both the MSX-type connector and the 26 pin IDC of the SY99 (and presumably the SY77). I tried it on the SY99, and had exactly the same problem (could read and write, but not format). Interestingly the SY99 only worked when parameters 00 and 01 on the HxC Gotek were set to 'auto'. It didn't like the Generic Shugart mode.

The connections for the 26 pin part of the adapter are identical to the official Yamaha floppy adapter board that they made for the SY99.

So perhaps this is an issue specific to Yamaha synths of that vintage.

Perhaps my particular Gotek drive has missing components (it was originally a 1.44Mb model, perhaps the READY line and/or DSKCHG is not connected? I'll investigate further.
EDIT: looked at the PCB and looks like everything is intact.

Jeff
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Re: Yamaha W7 and Gotek

Post by Jeff » Wed Jan 23, 2019 1:39 am

xuulan wrote:
Mon Jan 21, 2019 10:39 pm
Hi Jeff,

The interface was set to Generic Shugart. I tried MSX and a few others, but it didn't improve the situation.

The adapter board was designed to accommodate both the MSX-type connector and the 26 pin IDC of the SY99 (and presumably the SY77). I tried it on the SY99, and had exactly the same problem (could read and write, but not format). Interestingly the SY99 only worked when parameters 00 and 01 on the HxC Gotek were set to 'auto'. It didn't like the Generic Shugart mode.

The connections for the 26 pin part of the adapter are identical to the official Yamaha floppy adapter board that they made for the SY99.

So perhaps this is an issue specific to Yamaha synths of that vintage.

Perhaps my particular Gotek drive has missing components (it was originally a 1.44Mb model, perhaps the READY line and/or DSKCHG is not connected? I'll investigate further.
EDIT: looked at the PCB and looks like everything is intact.
Have you tried the non-gated firmware version ? :
https://hxc2001.com/download/floppy_dri ... rmware.zip

also : have you tried the pc interface modes ?

xuulan
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Joined: Sun Jan 06, 2019 8:04 pm

Re: Yamaha W7 and Gotek

Post by xuulan » Wed Jan 23, 2019 7:19 am

The non-gated firmware seems to have resolved the disk swapping issue. I can switch images and change will be recognized. I find I have to wait for a bit after the change or I get 'Disk not ready'.

Formatting still does not work. I've tried every single interface format with varying results. Mode 04 and 05 seemed to lock up the drive and required a parameter reset.

I've tried both HFE and IMG disk formats, 720k DD DOS format.

Jeff
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Re: Yamaha W7 and Gotek

Post by Jeff » Wed Jan 23, 2019 8:39 am

So finally you confirm that the disk swap is working with the non gated firmware in shugart mode ?
For the delay this is normal : this is a fixed value in the firmware to set the ready signal. I will provide something to set this value soon.

About the format issue, have you checked the index signal ?

xuulan
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Re: Yamaha W7 and Gotek

Post by xuulan » Wed Jan 23, 2019 10:14 pm

Hi Jeff,

Yes, it appears that the non-gated firmware has fixed the disk change problem. I will check the INDEX signal and let you know what I find.

Shugart mode did not work with the SY99, but PC 720k DD works fine.

Thank you for your support!

xuulan
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Re: Yamaha W7 and Gotek

Post by xuulan » Mon Jan 28, 2019 7:19 am

One problem has been solved. Formatting works on both the W7 and SY99. One of the Gotek drives I have is defective. Probably the INDEX signal as Jeff suggested.

Now, with my adapter, the SY99 works perfectly. The W7 *almost* works perfectly except for an issue with Disk Change. I had thought that the non-gated firmware solved the issue but it's more involved than that.

In diagnostic mode, the 'disk eject' test works perfectly. The W7 immediately detects when a different image is selected. However in normal operation it does not work correctly. The W7 (and the SY99 for that matter) have a 'disk status' option on the utility page which scans the disk directory. If you do a 'disk status' command immediately after changing a disk image, the W7 give a 'drive not ready' error, but after that the disk change is recognized. If you wait until the Gotek drive is ready after loading the image (5 seconds or so), then the disk change is not recognized.

This happens with both the normal and non-gated firmware.

Jeff
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Re: Yamaha W7 and Gotek

Post by Jeff » Mon Jan 28, 2019 9:45 am

Have you retried the pc mode with the W7 ?

xuulan
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Re: Yamaha W7 and Gotek

Post by xuulan » Mon Feb 04, 2019 11:31 pm

I believe I tried PC mode and it didn't work. However my Gotek is defective so I'll have to wait until the replacement arrives.

In the meantime I tried a Panasonic JU-257 drive from an Ensoniq EPS16, which did exactly the same thing: Loaded, saved, and formatted correctly, but would not register a disk change while in the 'Utility' menu. The disk change was recognized in the diagnostic menu.

Unfortunately the original floppy drive is not working at all, so I can't observe the signals with a logic analyzer to see what happens with the correct drive.

Jeff
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Re: Yamaha W7 and Gotek

Post by Jeff » Tue Feb 05, 2019 8:23 am

xuulan wrote:
Mon Feb 04, 2019 11:31 pm
I believe I tried PC mode and it didn't work. However my Gotek is defective so I'll have to wait until the replacement arrives.

In the meantime I tried a Panasonic JU-257 drive from an Ensoniq EPS16, which did exactly the same thing: Loaded, saved, and formatted correctly, but would not register a disk change while in the 'Utility' menu. The disk change was recognized in the diagnostic menu.

Unfortunately the original floppy drive is not working at all, so I can't observe the signals with a logic analyzer to see what happens with the correct drive.
What is defective on the gotek ?
There is a common issue with the floppy ribbons : They can be easily damaged -> the wires 2 or 34 can be damaged when you disconnect the ribbon. These wires are the disk change and the ready signals... would be interesting to replace it with another one.

xuulan
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Joined: Sun Jan 06, 2019 8:04 pm

Re: Yamaha W7 and Gotek

Post by xuulan » Sat Mar 02, 2019 7:59 pm

The fault with the HxC was one (or more) transistors that drive the signals to the floppy controller. I replaced all of the surface mount transistors and it's working now. Looks like one of them had a cold solder joint.

However I'm still having the same problem with the W7 not recognizing a disk change. The next step would be to hook my logic analyzer up to the original floppy drive and see what happens when a disk change occurs, and compare that with what the Gotek drive does. I will first need to make some kind of breakout cable for the original floppy drive.

EDIT: I meant to say the Gotek drive in the first sentence, not HxC...

Jeff
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Re: Yamaha W7 and Gotek

Post by Jeff » Sat Mar 02, 2019 8:04 pm

Please update your firmware :

https://hxc2001.com/custom_fw/

Set the "Non gated mode".

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