On Bootable CD's Floppy Emulation

[rloew]

If it were possible to create bootable CDs/DVDs with the bootable part >2.88MB, e.g. 120MB, the size of LS-120 diskette images ... but that would be another project.

The Bootable part of a CD can be made up to 36MB when emulating a Floppy (A:) or any size when emulating a Hard Disk (C:).

Edited July 13, 2011 by rloew

[jaclaz]

If it were possible to create bootable CDs/DVDs with the bootable part >2.88MB, e.g. 120MB, the size of LS-120 diskette images ... but that would be another project.

For the record it is very possible, just use El-Torito "Hard disk emulation" (instead of "Floppy emulation" or "No emulation").

Or you mean a super-floppy format?

Maybe one can use the Hard disk emulation with a "dual-mode" MBR/Bootsector like the makebootFAT one.

@rloew

Which media type do you need for a super-floppy larger than the 2.88 Mb?

Standard ones are:

• 0x00 - No Emulation
  
• 0x01 - 1.2 Mb floppy
  
• 0x02 - 1.44 diskette
  
• 0x03 - 2.88 diskette
  
• 0x04 - Hard disk emulation
  

@Multibooter, sorry for the OT. If you are interested in the matter can you start a new topic "CD related"?

@rloew, maybe we can continue this interesting discussion on the above new thread?

jaclaz

[dencorso]

@Multibooter: Would you please attach a zipped WinImage .IMA of a blank, fresh from format, 32MB floppy?

That would be interesting to study and can be useful, inclusive as a staring point to creating the 36MB floppy image RLoew mentioned. Thanks in advance.

[Multibooter]

Would you please attach a zipped WinImage .IMA of a blank, fresh from format, 32MB floppy?

That would be interesting to study and can be useful, inclusive as a staring point to creating the 36MB floppy image RLoew mentioned. Thanks in advance.

Hi dencorso,

I first formatted with SuperWriter32 -> Tool -> FD32MB Format a 1.44MB floppy disk to 32MB. I gave it the volume label "MSFN_ORG".

I then ran SuperWriter32 -> Tool -> DiskCopy, with the freshly-formatted 32MB floppy in the LS-240 drive.

When SuperWriter32 prompted to insert the target diskette, I made a copy of the temporary file Fd-32Img.dat, then cancelled the DiskCopy.

(see also my posting #24 http://www.msfn.org/board/topic/151957-ls-120-superdisk-drive-under-win98-and-dos/page__view__findpost__p__970671 )

I have attached a rared up copy of this temporary image file created by SuperWriter32. HTH.

Blank_Fd-32Img.rar

Edited July 13, 2011 by Multibooter

[rloew]

@rloew

Which media type do you need for a super-floppy larger than the 2.88 Mb?

Standard ones are:

• 0x00 - No Emulation
  
• 0x01 - 1.2 Mb floppy
  
• 0x02 - 1.44 diskette
  
• 0x03 - 2.88 diskette
  
• 0x04 - Hard disk emulation
  

0x03 allows up to 36MB

0x02 allows up to 18MB

0x01 allows up to 15MB

@Multibooter, sorry for the OT. If you are interested in the matter can you start a new topic "CD related"?

@rloew, maybe we can continue this interesting discussion on the above new thread?

Thread not yet in existence.

[dencorso]

Thread not yet in existence.

Now it is!

I hadn't realized that WinImage is able to deal with sparse images (images that omit almost all zeroed out sectors), so it was a pleasant surprise when it dawned on me the image Multibooter uploaded is a sparse one.

Of course I should have noticed that it was too small to be a byte-by-byte image, but I actually only noticed it on opening that image in WinHex. That's good news!

[jaclaz]

0x03 allows up to 36MB

0x02 allows up to 18MB

0x01 allows up to 15MB

I don't want to be a nuisance (or not more than usual ) but could you share:

1. the EXACT size in bytes of those?
   
2. an example mkisofs command line to build such a super-floppy .iso?
   

(or some reference to the above if available)

Attached is an image of a real unusual superfloppy I've crated some time ago... It can be made bootable, of course. And when transferred to a physical Zip100, after running SYS.COM on it, it realy does boot OK (I did the test).

Any reason for the 32K sized clusters?

It should be 2K:

http://support.microsoft.com/kb/140365/en-us

and it really should be FAT16.

Or am I missing something?

jaclaz

Edited July 14, 2011 by jaclaz

[rloew]

0x03 allows up to 36MB

0x02 allows up to 18MB

0x01 allows up to 15MB

I don't want to be a nuisance (or not more than usual ) but could you share:

1. the EXACT size in bytes of those?
   
2. an example mkisofs command line to build such a super-floppy .iso?
   

(or some reference to the above if available)

0x03: 1024*2*36 * 512 = 37,748,736

0x02: 1024*2*18 * 512 = 18,874,368

0x01: 1024*2*15 * 512 = 15,728,640

I have never used mkisofs, so I have no idea what it's syntax is.

Edited July 16, 2011 by dencorso
Moved part of content to new Supperfloppy thread

[rloew]

@rloew: If you don't use mkisofs, what do you use to create a .iso?

jaclaz

After crashing Nero with some very long Directories, I wrote my own set of CD Writers / ISO Builders. Adding El Torito support was simple. A manual option lets me force Type 0x03 rather than 0x04 for the Boot Image when using Images between 2.88MB and 36MB.

[dencorso]

Here is my first attempt at creating a 36 MiB image, as per RLoew's specification, and my first attempt at a sparse image. I think I did it correctly, but please do verify it. WinImage loads it OK. It's a 4 kiB cluster FAT-16 filesystem, which follows closely Multibooter's original 32 MiB image. It should be straightforward to add zeroes to create a full image, if necessary.

Fd-36Img_Full.7z

[jaclaz]

Something has got lost in the movements forward and back of the posts between the two three topics.

Just for the record and for reference, here is the "Superfloppy one":

And here is the "LS-120" one:

http://www.msfn.org/board/topic/151957-ls-120-superdisk-drive-under-win98-and-dos/

This (partly) remained on the "wrong" thread:

page__st__11

@rloew

If you don't use mkisofs, what do you use to create a .iso?

After crashing Nero with some very long Directories, I wrote my own set of CD Writers / ISO Builders. Adding El Torito support was simple. A manual option lets me force Type 0x03 rather than 0x04 for the Boot Image when using Images between 2.88MB and 36MB.

I see.

Is this app (or set of apps) available?

If yes, can you post a link to it?

Or is it for "private use"?

If yes, can you attach a couple of generated (empty, or with a few redistributable files in them) .iso's?

Hex editing a built .iso to set a byte to 0x03 instead of 0x04 is not a problem, but I would like to have an "universal" solution, such as mkisofs may provide.

@dencorso

Since you are also on this band-wagon and you are in the "make queer filesystems trade", can you prepare three empty superfloppy images sized EXACTLY:

0x03: 1024*2*36 * 512 = 37,748,736

0x02: 1024*2*18 * 512 = 18,874,368

0x01: 1024*2*15 * 512 = 15,728,640

I seemingly cannot download the image you posted, but common sense tell's me that no matter how much sparse you made it, it cannot be 708 bytes... (an upload problem? ) ->correction, I managed to download it, now what do you propose to "un-sparse" it?

BTW, it should not be a "sparse" image, but rather a "truncated"one.

I would use DCOPYNT :

http://www.winimage.info/forum/viewtopic.php?f=3&t=3429

http://users.pandora.be/jbosman/applications.html

In any case a "normal, non-sparse, non-truncated" image, if empty, will compress in 7z to a few thousands byte....

I will gladly do the experiments with mkisofs to reproduce.....

@all

Only seemingly off-topic, I find this simplified approach very, very smart:

http://reboot.pro/9916/page__st__28'>http://reboot.pro/9916/page__st__28

the whole thread may contain useful info:

http://reboot.pro/9916/

jaclaz

Edited July 16, 2011 by jaclaz

[rloew]

@rloew

If you don't use mkisofs, what do you use to create a .iso?

After crashing Nero with some very long Directories, I wrote my own set of CD Writers / ISO Builders. Adding El Torito support was simple. A manual option lets me force Type 0x03 rather than 0x04 for the Boot Image when using Images between 2.88MB and 36MB.

I see.

Is this app (or set of apps) available?

If yes, can you post a link to it?

Or is it for "private use"?

If yes, can you attach a couple of generated (empty, or with a few redistributable files in them) .iso's?

RFDISK and RFORMAT are already on my Website. These are used to Create and Populate the Bootable Image.

Partition Imagers are everywhere.

I didn't Package my CD/DVD Utilities for sale as I had not seen any particular interest in their added features. People seemed happy with what they have.

I'm not sure what the value of an Empty ISO is. It will just attempt to boot an empty Partition and fail. You still need to populate the Bootable Image and probably the rest of the CD as well.

In any case dencorso is well on the way to creating one.

@dencorso: Bootable Floppy Images need to be FAT12. Otherwise your new Image is fine.

Edited July 16, 2011 by rloew

[jaclaz]

I'm not sure what the value of an Empty ISO is. It will just attempt to boot an empty Partition and fail. You still need to populate the Bootable Image and probably the rest of the CD as well.

It would be a start, to find a way to reproduce the three .iso's easily (with a populated image).

If you could create three .iso's with the given superfloppy sizes and freedos it would be perfect.

If you check the given before link:

http://reboot.pro/9916/page__st__28

you will see that using the simple, alternate approach, and as long as we want to only populate the superfloppy image, we can simply use the "header" of the .iso file in conjunction with a "populated image".

The "rest of the CD" we will find later a way to populate, if we can reproduce the "header" with mkisofs + (if needed) a few hex edits via batch, rest of the CD should be a "piece of cake" .

jaclaz

Edited July 16, 2011 by jaclaz

[rloew]

I'm not sure what the value of an Empty ISO is. It will just attempt to boot an empty Partition and fail. You still need to populate the Bootable Image and probably the rest of the CD as well.

It would be a start, to find a way to reproduce the three .iso's easily (with a populated image).

If you could create three .iso's with the given superfloppy sizes and freedos it would be perfect.

If you check the given before link:

http://reboot.pro/9916/page__st__28

you will see that using the simple, alternate approach, and as long as we want to only populate the superfloppy image, we can simply use the "header" of the .iso file in conjunction with a "populated image".

The "rest of the CD" we will find later a way to populate, if we can reproduce the "header" with mkisofs + (if needed) a few hex edits via batch, rest of the CD should be a "piece of cake" .

jaclaz

For me, populating the Boot Image and the rest of the CD is the major part of the task. Extraction and Burning are straightforward.

There is no particular reason to make three different sizes as Type 0x03 can handle anything from 36KiB to 36MiB.

I usually create an Image appropriate for the amount of actual data I need on the Bootable Part and process it accordingly.

Without custom scripts, Freedos is not going to do anything once it is loaded. You might as well just stick in a Floppy.

Creating a "header" that includes the El Torito Header will require a number of Patches if you start Populating the rest of the CD/DVD. I could do it. Maybe you could do it. How many others do you think could do it. A Program would need to be written to automate the Process. Sounds like an awful lot of work to avoid buying my tools.

[LoneCrusader]

I didn't Package my CD/DVD Utilities for sale as I had not seen any particular interest in their added features. People seemed happy with what they have.

A quick question/observation... that has the potential to make this get off topic AGAIN...

Do your/can your CD/DVD utilities work with Blu-Ray images/devices? I know Multibooter was having burn-quality issues during his tests, of course it is still unknown whether it was due to software, hardware, or media quality...

In the event it is software related, your solutions might end up being the only "quality" Blu-Ray burning application available for Windows 9x...