Log in

View Full Version : Dumping files from dos1.0 floppy disc image

duga
June 14th, 2012, 02:22
Currently I try reversing dos 1.0 (on bochs on windows 7 - no boot sector signature and no 5 1/4 160 KB floppy disc drive) and encounter on, for me quite serious, problem. It means, transferring data between host and guest system. I tried it make exchanging floppy discs images (and opening it with WinImage - it failed), and currently I dump data files from hex-editor what is not very suitable for me. How can I do it more conveniently?

P.S. Dos 1.0 supports only (according to my knowledge) 5 1/4 160 KB floppy disc drive.
Woodmann
June 14th, 2012, 21:42
Howdy,

I am a little confused what it is your trying to do.
You have the files on computer A and want to put
them on computer B ?

I dont recall DOS having an image file.
They are just files. You copy them the way they are.

Woodmann
duga
June 15th, 2012, 02:07
Quote:
[Originally Posted by Woodmann;92748]Howdy,

I am a little confused what it is your trying to do.
You have the files on computer A and want to put
them on computer B ?

I dont recall DOS having an image file.y
They are just files. You copy them the way they are.

Woodmann


I am trying to exchange data between host and guest system in bochs. I cannot handle with it opening images of floppies (I am emulating 5 1/4 floppy discs with bochs - also a system one) with WinImages, because it cannot open. I currently am working it around with dump data from floppy image (in hex-editor - icy hexplorer). Shortly I am trying to extract files from floppy image what cannot be done (in my case) with WinImage. I hope, your confusion is only due to my bad english skills ;>

I have only one machine - and host system means windows7, guest system means dos1.0. Dos1.0 is emulated with bochs on windows7
Woodmann
June 15th, 2012, 23:00
Yes it is bad English, but lets try.

You are trying to copy the files?
Make them run in Bochs?
Interact with win7?
Run in win7?
What are the file extensions ?

Woodmann
Aimless
June 16th, 2012, 02:06
Duga.

Total confusion time.

What do you want to achieve? And why are you emulating DOS 1.0 on Bochs?

You want to transfer some files. Where are the files? What is the source of those files you want to transfer --- Are they on 5.4 floppies? Or images of 5.4 floppies? Who made those images? --- Again, basically, why do you need to emulate Dos 1.0 on Bochs?

Have Phun
duga
June 16th, 2012, 07:11
Quote:
[Originally Posted by Woodmann;92756]Yes it is bad English, but lets try.

You are trying to copy the files?
Make them run in Bochs?
Interact with win7?
Run in win7?
What are the file extensions ?

Woodmann


Yes, I try to copy files, which are on the 5 1/4 floppy disc image (simple *.img) , to my hard disc (not extracting them via hex-editor from floppy disc image)
Yes, I have to emulate dos1.0 on bochs. Bochs runs on windows 7 (Dos1.0 cannot run in a normal way, because I do not have any floppy disc drive (especially 5 1/4 one)).
Dos 1.0 does not have bios 0x55AA signature (I know I could it patch) and I prefer run such old system on the emulator (dos crashes more frequently than windows).
Even mounting the image via disc floppy emulator fails - simply windows 7 detect the floppy disc as "unformatted".

I want only extract *.com and *.exe files from 5 1/4 floppy disc image. (binaries of dos1.0 which resides on this floppy disc image)
It should not interact with windows7 except from trying to transfer *.com *.exe (dos binaries) to windows 7.
I want only to disassembly them with IDA, and not to play with not very convinent for me debug.com program which resides on dos1.0
Aimless
June 16th, 2012, 12:31
Hi there,

Mind sharing those image files?

As I understand it, you want to run Dos 1.0

But the DOS 1.0 files are on a 5.4 floppy images.

And you have not yet managed to extract the files (.exe and .com)

Is that correct?

If so, please share the image files.

Have Phun
Woodmann
June 16th, 2012, 21:46
I bet they are not true .img files.
I dont ever recall the early DOS versions
to use such extensions.

I think they were created so they would
run on newer OS.

Try opening the .img file with something like
poweriso or a similar prog.
If you cant see the files inside then you will
have to make them available so we can
see what they really are.

Woodmann
Aimless
June 16th, 2012, 21:53
Share those files, buddy. Share those files.

Have Phun
duga
June 17th, 2012, 04:43
5 1/4 160KB Floppy disc image: https://docs.google.com/open?id=0B7jdHHlIQKAxVmF4elZDRm9FMkE
Example binary, which I want to get from this image: https://docs.google.com/open?id=0B7jdHHlIQKAxd1RIME1uTEliTGc

I want to get binaries from the list: http://thestarman.narod.ru/DOS/ibm100/index.html#INTR not carving them from the image via hex-editor (offset && length, copy && paste from file to another file)

Is there any simpler method not playing with hex-editor ?
blabberer
June 17th, 2012, 14:39
not sure what you want but leeching the ibmbio.com from distr.img is one liner with dd (you can also try mathieu suiches windd if the linux dd of gnuwin32 port does not work in win7)

see if this helps

C:\>dd if=c:\distr.img of=gtr bs=1 count=1920 skip=3584
1920+0 records in
1920+0 records out
1920 bytes (1.9 kB) copied, 0.015625 seconds, 123 kB/s

C:\Downloads>fc gtr IBMBIO.com
Comparing files gtr and IBMBIO.COM
FC: no differences encountered
duga
June 18th, 2012, 07:16
Quote:
[Originally Posted by blabberer;92766]not sure what you want but leeching the ibmbio.com from distr.img is one liner with dd (you can also try mathieu suiches windd if the linux dd of gnuwin32 port does not work in win7)

see if this helps

C:\>dd if=c:\distr.img of=gtr bs=1 count=1920 skip=3584
1920+0 records in
1920+0 records out
1920 bytes (1.9 kB) copied, 0.015625 seconds, 123 kB/s

C:\Downloads>fc gtr IBMBIO.com
Comparing files gtr and IBMBIO.COM
FC: no differences encountered


Yes, it is what I want, but I did with hex-editor. Could you do it without extracting them from file, only "open" disc image and copy files with drag and drop. Both methods yours and mine are not very convinient (especially if you does not have offsets to file - as you had, but you have to parse fat12 table to get to know where it is.)
blabberer
June 18th, 2012, 15:44
i don't think dos boxes 30 years ago had drag drop facility

you can change the attribute of the hidden file and then copy it somewhere using command line tools (viz attrib and copy)

here is a bochs snap shot of 38 file listing and then changing the attribute of ibmbio.com and then copying it to ms ramdrive at c:\

Code:




DEBUG.COM       DISKCOMP.COM    DISKCOPY.COM    DONKEY.BAS      EDLIN.COM

FORMAT.COM      FORTY.BAS       HAT.BAS         HUMOR.BAS       LINK.EXE

MARCH.BAS       MODE.COM        MORTGAGE.BAS    MUSIC.BAS       PIECHART.BAS

POP.BAS         SAKURA.BAS      SAMPLES.BAS     SCALES.BAS      SPACE.BAS

STARS.BAS       SYS.COM         TIME.COM

        38 file(s)        136,405 bytes

         0 dir(s)           6,144 bytes free



B:\>attrib -s -h -r ibmbio.com



B:\>copy ibmbio.com c:\duga.com

        1 file(s) copied



B:\>c:



C:\>dir duga.com



 Volume in drive C is MS-RAMDRIVE

 Directory of C:\



DUGA     COM         1,920  07-23-81 12:00a

         1 file(s)          1,920 bytes

         0 dir(s)       1,484,800 bytes free



C:\>ß



if you want it physically to some hard disk you can insert a blank floppy (virtual floppy in a:\) format it and copy the ibmbio.com to that floppy

Code:


A:\>dir



 Volume in drive A is DUGA

 Volume Serial Number is 334B-09F0

 Directory of A:\



COMMAND  COM        93,880  05-11-98  8:01p

         1 file(s)         93,880 bytes

         0 dir(s)       1,071,104 bytes free



A:\>copy c:\duga.com .

        1 file(s) copied



A:\>dir



 Volume in drive A is DUGA

 Volume Serial Number is 334B-09F0

 Directory of A:\



COMMAND  COM        93,880  05-11-98  8:01p

DUGA     COM         1,920  07-23-81 12:00a

         2 file(s)         95,800 bytes

         0 dir(s)       1,069,056 bytes free



A:\>ß




which you can mount using virtual machine floppy emulation or

using vfdwin by kato ken (source forge)
reverser
June 20th, 2012, 16:02
DOS 1.0 boot sector is not standard FAT bootsector so most tools won't recognize it.
http://www.pagetable.com/?p=165