2.8" QD Disk Emulation

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joenoone
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2.8" QD Disk Emulation

Post by joenoone » Mon Nov 07, 2011 10:47 pm

Hi,
Wonderful design, something sorely needed. However, I've been looking for a replacement / substitute for the 2.8" QD Disk Drive as I have a Roland S-10 sampler keyboard that uses these that I'd like to find a replacement for the failed drive.

At the very least, does anyone know where I can find I/O details on those drives? I had thought about trying to make an emulator myself (via Arduino or something else) but have been at a loss as to where to even find any useful information on the QD drives.

Any help is greatly appreciated...

[EDIT 15 August 2019]
The QuickDisk emulation is now supported by the HxC Firmware for Gotek drive. Please follow the link :
viewtopic.php?f=2&p=21001#p20956

Randaj38
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Re: 2.8" QD Disk Emulation

Post by Randaj38 » Mon Jan 23, 2012 7:15 pm

Just wondering if you got any further on this question? I've got two s10s and had to repair the drives...then ended up getting an Alesis data disk to patches via midi. Would still love a better solution that could be built into the S10 so I don't have to carry and set up extra midi gear at gigs...

Any help on replacing the 2.8QD with something better much appreciated

Jeff
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Re: 2.8" QD Disk Emulation

Post by Jeff » Tue Jan 24, 2012 1:46 am

Randaj38 wrote:Just wondering if you got any further on this question? I've got two s10s and had to repair the drives...then ended up getting an Alesis data disk to patches via midi. Would still love a better solution that could be built into the S10 so I don't have to carry and set up extra midi gear at gigs...

Any help on replacing the 2.8QD with something better much appreciated
Which kind of interface use this disk drive ?

Randaj38
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Re: 2.8" QD Disk Emulation

Post by Randaj38 » Fri Jan 27, 2012 7:48 am

There isn't much info on the nature of the 2.8 Quick disk other than it was used in devices such as :

The Roland S-10, AKai X7000 SMith and Corona Wordprocessors. It was mainly used in the Faircom Nintendo game systems and the drive was made by Mitsumi. HEre is what I found...
Quick Disk as used in the Famicom Disk System holds 64 kB of data per side, requiring a manual turn-over to access the second side.
Unusually, the Quick Disk utilizes "a continuous linear tracking of the head and thus creates a single spiral track along the disk similar to a record groove."[45] This has led some to compare it more to a "tape-stream" unit than typically what is thought of as a random-access disk drive.[47]

So overall there is no concept of an index or directory...not even sure their is a traditional dis controller. Only one file can be stored per side. Almost a fast version of a cassette tape.

Jeff
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Re: 2.8" QD Disk Emulation

Post by Jeff » Fri Jan 27, 2012 8:13 am

Randaj38 wrote:There isn't much info on the nature of the 2.8 Quick disk other than it was used in devices such as :

The Roland S-10, AKai X7000 SMith and Corona Wordprocessors. It was mainly used in the Faircom Nintendo game systems and the drive was made by Mitsumi. HEre is what I found...
Quick Disk as used in the Famicom Disk System holds 64 kB of data per side, requiring a manual turn-over to access the second side.
Unusually, the Quick Disk utilizes "a continuous linear tracking of the head and thus creates a single spiral track along the disk similar to a record groove."[45] This has led some to compare it more to a "tape-stream" unit than typically what is thought of as a random-access disk drive.[47]

So overall there is no concept of an index or directory...not even sure their is a traditional dis controller. Only one file can be stored per side. Almost a fast version of a cassette tape.
to be able to do something i really need more informations.

I know that the Famicom Disk System used this kind of disk, but the track format is different no ?

is there some kind of disk image somewhere ?

goldkillah
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Joined: Wed May 16, 2012 11:34 pm

Re: 2.8" QD Disk Emulation

Post by goldkillah » Thu May 17, 2012 12:28 am

A QD block diagram, a Read/Write timing diagram and a pinout would be enough or is more usefull a disk image ?

pulkomandy
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Re: 2.8" QD Disk Emulation

Post by pulkomandy » Thu May 17, 2012 8:37 am

pinout and timings will help knowing if it can be done. If so, infos on the disk structure will then make it actually possible :)

elmegil
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Re: 2.8" QD Disk Emulation

Post by elmegil » Wed Jul 18, 2012 2:20 pm

I have an S-10, and while I don't have the chops to really help much with the emulator work (or at least not the time) I would LOVE to see something like this come to be.

There are timing diagrams and other details for the QD driver chip in the service notes for the S-10, which are available at:

http://elektrotanya.com/roland_s-10.pdf/download.html

I hope this helps move things along :-D

Randel
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Re: 2.8" QD Disk Emulation

Post by Randel » Thu Jan 03, 2013 3:41 pm

I too am very interested in an emulator for the Mitsumi 2.8" drive.

I am an existing customer with an HxC for an Emax, and would like a solution to replace the Mitsumi 2.8" drive in my Akai S700 sampler.

These drives are also found in the Roland S-10, MKS100 and S-220, Korg SQ1-D and SQD-8, Akai S700 and X7000, and the Yamaha MDF1.

Most notably, they are used in the Nintendo Famicon gaming system, which has a large and loyal community of supporters.

The original drive from Mitsumi has a rubber drive belt that fails over time, rendering the device inoperable. Replacing the belt requires disassembly of much of the drive mechanism, and it is often necessary to re-align the head after replacement.

I would be willing to assist in design, development, or troubleshooting of such a project.

There is a great deal of technical information on the Mistumi QD drive included in documents on the Nintendo Famicon System - some of the information explains the interface between the game system and the disk controller, yet some of the information focuses on the disk and data structure.

Please contact me if you would like to explore this further.

Here are a few links:

http://nesdev.com/FDS%20technical%20reference.txt - Technical Reference

http://nesdev.com/fdsloadr.zip - This zip file contains the source code for a PC-based disk emulator for the Mitsumi drive, as well as a text description of its operation and electrical connection to the parallel port

-Randel

Jeff
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Re: 2.8" QD Disk Emulation

Post by Jeff » Fri Jan 04, 2013 8:39 pm

Thanks for these informations.

About the QuickDisk, this should not be a problem with the actual HxC hardware for read process.
For the write process, i must check how the FDC write to the disk. It maybe need more memory than the actual hxc have.

Which FDC are used in the S700 ?

Martythevampire
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Re: 2.8" QD Disk Emulation

Post by Martythevampire » Mon Oct 28, 2013 6:56 pm

Hi there,

Is there any update on the 2.8" Quick Disk support?

There is some really detailed operation information, block diagrams and circuit schematics on the Akai MD280 2.8" QD drive that works with the Akai S612) in the service manual here http://fa.utfs.org/diy/akai_s612/index.html (Part 2 covers the QD operation).

I really do hope this is possible. I'm sure the operation is the same, if not identical for the Roland S10, MKS100, Akai X7000, S700 and the Nintendo Famicon (?) as they all use this type of disk.

Finding these is getting quite hard now (and expensive).

I already have a HxC for my Mirage and Prophet 2000 samplers. Would love to see one of these replace the MD280 drive for my Akai S612.

Best regards, Marty

Jeff
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Re: 2.8" QD Disk Emulation

Post by Jeff » Wed Nov 06, 2013 7:53 am

Martythevampire wrote:Hi there,

Is there any update on the 2.8" Quick Disk support?

There is some really detailed operation information, block diagrams and circuit schematics on the Akai MD280 2.8" QD drive that works with the Akai S612) in the service manual here http://fa.utfs.org/diy/akai_s612/index.html (Part 2 covers the QD operation).

I really do hope this is possible. I'm sure the operation is the same, if not identical for the Roland S10, MKS100, Akai X7000, S700 and the Nintendo Famicon (?) as they all use this type of disk.

Finding these is getting quite hard now (and expensive).

I already have a HxC for my Mirage and Prophet 2000 samplers. Would love to see one of these replace the MD280 drive for my Akai S612.

Best regards, Marty
There is missing the most important stuff : how are encoded the data on the track ?

elmegil
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Re: 2.8" QD Disk Emulation

Post by elmegil » Mon Feb 24, 2014 6:11 am

I'm still interested in this as well. Is there some way you would recommend to determine the disk encoding? My understanding from the reading I've done is it's pretty simplistic.

I have a Roland S-10 and could possibly do experiments with a bit of pointing in the right direction. Is there some signal capture (standard logic probes?) that you typically use to reverse engineer this kind of thing?

Jeff
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Re: 2.8" QD Disk Emulation

Post by Jeff » Mon Feb 24, 2014 9:04 am

elmegil wrote:I'm still interested in this as well. Is there some way you would recommend to determine the disk encoding? My understanding from the reading I've done is it's pretty simplistic.

I have a Roland S-10 and could possibly do experiments with a bit of pointing in the right direction. Is there some signal capture (standard logic probes?) that you typically use to reverse engineer this kind of thing?
In fact i am working on a new design based directly on the stream flux. By this no need to "understand" what is going in/out ;).

Stay tuned!

djbat
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Re: 2.8" QD Disk Emulation

Post by djbat » Fri Mar 21, 2014 3:04 am

*bump*

Would be interested in the results of this as well! Keep us informed Jeff :)

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