FlashFloppy / Gotek floppy emu working with OSI disk images
Posted: Fri Oct 19, 2018 5:56 am
(moved this into it's own topic)
OSI disk dump to gotek Flash Floppy conversion success!
[Edit 2019-09-16: So eventually I learned there are (at least) two emulator conversion projects for the Gotek floppy disk emulator hardware, HxC which is a closed-source product for sale, and Flash Floppy an open source project that uses the same "HFE" disk-image file format as HxC. The OSI to HFE conversion works well with Flash Floppy for both read and write, but with HxC only read compatibility seems to work, writing tends to crash the HxC firmware and the drive has to be powered down or reset. These problems may be corrected in future firmware releases or software updates and may no longer apply when you read this, but at this point Flash Floppy is the best choice for OSI replacements. -Mark]
Hi All,
So I've been working on software to do OSI <-> HFE conversions, made possible by the the work Phil & Dave did getting a working gotek HxC kyrofux conversion. Thanks! Now it's time to let it out into the world for some testing. Eventually I hope the HxC firmware will support conversions automatically, but this is a good 1st step.
To convert the OSI disk dump images to HxC compatible images, the timing delays present after index holes and between sectors need to be recreated and the disk data needs to be converted into an inverted serial bitstream (8E1/8N1) simulating the OSI 6850 disk hardware. Both OS65D and OS65U conversions are supported. In addition, other OS like PicoDOS should work fine as long as they stick to the general OSI disk encoding schemes. The only other detail I discovered is that the raw FM disk images used with HxC needed to be 2 sided. The 2nd side is created as blank. The resulting HFE files are at least 10x larger than the OSI disk dumps!
I have been able to test 5.25" conversions, but not 8" conversions... they may work too. Dave is working on getting a kyroflux dump of an 8" disk so we can verify timings.
One cool thing is you can mount a 8" OS65D image on a 5.25" system when you specify a bitrate that is compatible with the 5.25" hardware. (use the '-5' command-line option) Write testing on this configuration has not been done but reading seems to work fine.
Normal 5.25" disk writes do work fine, but I am still leery of rewriting a sector in the middle of a multi-sector track. Timings may have to be tweaked.
My C4PMF setup includes an inline 'D-13'-like data separator between my OSI drives and the controller, so simply plugging in a converted Gotek drive was all I needed to do to get up and running. Phil outlined the gotek conversion here: http://www.osiweb.org/osiforum/viewtopi ... =420#p2687 Once converted, I rename the files DSKA0000.HFE, DSKA0001.HFE etc.. to mount them.
Anyway it's available on the Tools page on my website http://osi.marks-lab.com the direct link is http://osi.marks-lab.com/software/files ... OSIHFE.zip
Source is included so you can change things if you need to. -oh it does compile on Mac & probably linux too without too much changing. Windowss & Mac builds are included.
WinOSI is getting native HFE file support too!
Here is the readme....
OSI disk dump to gotek Flash Floppy conversion success!
[Edit 2019-09-16: So eventually I learned there are (at least) two emulator conversion projects for the Gotek floppy disk emulator hardware, HxC which is a closed-source product for sale, and Flash Floppy an open source project that uses the same "HFE" disk-image file format as HxC. The OSI to HFE conversion works well with Flash Floppy for both read and write, but with HxC only read compatibility seems to work, writing tends to crash the HxC firmware and the drive has to be powered down or reset. These problems may be corrected in future firmware releases or software updates and may no longer apply when you read this, but at this point Flash Floppy is the best choice for OSI replacements. -Mark]
Hi All,
So I've been working on software to do OSI <-> HFE conversions, made possible by the the work Phil & Dave did getting a working gotek HxC kyrofux conversion. Thanks! Now it's time to let it out into the world for some testing. Eventually I hope the HxC firmware will support conversions automatically, but this is a good 1st step.
To convert the OSI disk dump images to HxC compatible images, the timing delays present after index holes and between sectors need to be recreated and the disk data needs to be converted into an inverted serial bitstream (8E1/8N1) simulating the OSI 6850 disk hardware. Both OS65D and OS65U conversions are supported. In addition, other OS like PicoDOS should work fine as long as they stick to the general OSI disk encoding schemes. The only other detail I discovered is that the raw FM disk images used with HxC needed to be 2 sided. The 2nd side is created as blank. The resulting HFE files are at least 10x larger than the OSI disk dumps!
I have been able to test 5.25" conversions, but not 8" conversions... they may work too. Dave is working on getting a kyroflux dump of an 8" disk so we can verify timings.
One cool thing is you can mount a 8" OS65D image on a 5.25" system when you specify a bitrate that is compatible with the 5.25" hardware. (use the '-5' command-line option) Write testing on this configuration has not been done but reading seems to work fine.
Normal 5.25" disk writes do work fine, but I am still leery of rewriting a sector in the middle of a multi-sector track. Timings may have to be tweaked.
My C4PMF setup includes an inline 'D-13'-like data separator between my OSI drives and the controller, so simply plugging in a converted Gotek drive was all I needed to do to get up and running. Phil outlined the gotek conversion here: http://www.osiweb.org/osiforum/viewtopi ... =420#p2687 Once converted, I rename the files DSKA0000.HFE, DSKA0001.HFE etc.. to mount them.
Anyway it's available on the Tools page on my website http://osi.marks-lab.com the direct link is http://osi.marks-lab.com/software/files ... OSIHFE.zip
Source is included so you can change things if you need to. -oh it does compile on Mac & probably linux too without too much changing. Windowss & Mac builds are included.
WinOSI is getting native HFE file support too!
Here is the readme....
-MarkV1.0.2
OSIHFE is a Windows command-line utility used to convert between OSI Disk Dump images and HxC Floppy Emulator RAW FM disk images.
OSIHFE recognizes "OSI" HFE image files and OSI disk dump files and will convert between them.
OSIHFE restores the timing delays lost when dumping files using the OSIDump utilities.
It simulates the disk reading and writing process generating flux transitions used by the HxC Floppy Emulator. It can write both OS65D and OS65U format images. The target HFE files are created as double-sided RAW FM images which seem most compatible with HxC devices.
Usage:
OSIHFE -[bdiov5] infile [outfile]
( If [outfile] is not specified, a target file is automatically based on input filetype)
-b65D5/-b65D8/-b65U8 outfile create blank OSI HFE image of specified type
-d infile list directory contents
-i infile identify file type (OS65D5, OS65D8, OS65U)
-5 write 8" image at 5.25" bit rate to allow mounting 8" image on 5.25" system
-o overwrite existing output file
Since a target filename will be generated automatically based on input file, all you need to do is drag & drop the OSI disk image onto OSIHFE for it to generate the corresponding HFE file or vice versa. A Mac build has been provided or you can build one from included source.