Using dd to copy copy-protected floppies

Using dd to copy copy-protected floppies

Post by Duane Evenso » Fri, 31 Mar 2000 04:00:00



I have an old DOS game on a copy protected diskette (720 kB). I thought
dd would allow me to make a backup -- no good. I'm guessing that I need
to change the floppy dirk parameters using setfdparm. Is this right?
Does anyone know how to get the needed disk parameters?
What should I do?

Thanks,
Duane Evenson

 
 
 

Using dd to copy copy-protected floppies

Post by Dances With Cro » Fri, 31 Mar 2000 04:00:00


On Thu, 30 Mar 2000 04:29:41 -0700, Duane Evenson

Quote:>I have an old DOS game on a copy protected diskette (720 kB). I thought
>dd would allow me to make a backup -- no good. I'm guessing that I need
>to change the floppy dirk parameters using setfdparm. Is this right?
>Does anyone know how to get the needed disk parameters?

$ dd if=/dev/fd0D720 of=diskimage.raw bs=1k

Your system may call the device file "fd0d720".  Also, keep in mind that
sometimes, older games/whatnot used very strange means of reading/writing
the disks, all in the name of copy protection, so it might not work
regardless....

--
Matt G / Dances With Crows              \###| Programmers are playwrights
There is no Darkness in Eternity         \##| Computers are lousy actors
But only Light too dim for us to see      \#| Lusers are vicious drama critics
(Unless, of course, you're working with NT)\| BOFHen burn down theatres.

 
 
 

Using dd to copy copy-protected floppies

Post by Martin Beie » Fri, 31 Mar 2000 04:00:00


Quote:> I have an old DOS game on a copy protected diskette (720 kB). I thought
> dd would allow me to make a backup -- no good. I'm guessing that I need
> to change the floppy dirk parameters using setfdparm. Is this right?
> Does anyone know how to get the needed disk parameters?
> What should I do?

Hmm, which device are you using? Consult
/usr/src/linux/Documentation/devices.txt.
You may want to try some different ones (/dev/fd?[h|u]720). Perhaps this
helps.


 
 
 

Using dd to copy copy-protected floppies

Post by Leonard Even » Fri, 31 Mar 2000 04:00:00



> I have an old DOS game on a copy protected diskette (720 kB). I thought
> dd would allow me to make a backup -- no good. I'm guessing that I need
> to change the floppy dirk parameters using setfdparm. Is this right?
> Does anyone know how to get the needed disk parameters?
> What should I do?

> Thanks,
> Duane Evenson

Which device did you copy from?  It shouldn't be /dev/fd0.
--


Dept. of Mathematics, Northwestern Univ., Evanston, IL 60208

 
 
 

Using dd to copy copy-protected floppies

Post by Jehs » Fri, 31 Mar 2000 04:00:00



> I have an old DOS game on a copy protected diskette (720 kB). I thought
> dd would allow me to make a backup -- no good. I'm guessing that I need
> to change the floppy dirk parameters using setfdparm. Is this right?
> Does anyone know how to get the needed disk parameters?

One copy-protected program actually used the disk's serial number
to verify that it was genuine. I don't know if dd actually reads &
writes the serial number, but if it doesn't, you need to set it to
the same serial number and it should work.
Also, copy from the 720k floppy device in linux (forgot its name)

Moshe

--

Geek code v3.12 (www.geekcode.com):
GCS/E d- s+:-- a-- C++$ UL++>+++$ P+>++ L+++>$ E--- W+ N++ w--
!O M-- V? PS+ PE Y+ !PGP t 5? X+ R- tv b- DI+ D+ G e>++ h r y

 
 
 

Using dd to copy copy-protected floppies

Post by Rod Bric » Fri, 31 Mar 2000 04:00:00


Some disks used a couple of physically bad sectors to prevent copying.
Upon bootup, the software on the disk would read those bad sectors, if
they were indeed bad (returned an error), the software would note this
and proceed normally.  If the sectors were good (no errors), it probably
meant the disk was a copy, and the software would fail to proceed.


> I have an old DOS game on a copy protected diskette (720 kB). I thought
> dd would allow me to make a backup -- no good. I'm guessing that I need
> to change the floppy dirk parameters using setfdparm. Is this right?
> Does anyone know how to get the needed disk parameters?
> What should I do?

> Thanks,
> Duane Evenson

--
Rod Brick
PSW Technologies
Austin, Texas
http://www.psw.com
 
 
 

Using dd to copy copy-protected floppies

Post by Duane Evenso » Fri, 31 Mar 2000 04:00:00


I tried /dev/fd0 and /dev/fd0D720 and got the same (byte-wise) files. What
device should I be using?


> > I have an old DOS game on a copy protected diskette (720 kB). I thought
> > dd would allow me to make a backup -- no good. I'm guessing that I need
> > to change the floppy dirk parameters using setfdparm. Is this right?
> > Does anyone know how to get the needed disk parameters?
> > What should I do?

> > Thanks,
> > Duane Evenson

> Which device did you copy from?  It shouldn't be /dev/fd0.
> --


> Dept. of Mathematics, Northwestern Univ., Evanston, IL 60208

 
 
 

Using dd to copy copy-protected floppies

Post by j.. » Fri, 31 Mar 2000 04:00:00


    One of the old methods of copy protecting disks was to use a laser
to burn marks in them to get "bad" sectors. Therefore these would be normally
marked offically bad using DOS's diskcopy. I don't know if dd will do what you
want, but there were a number of DOS programs to overcome this like copyiipc,
masterkey, and others... but at this point good luck finding them. :) (best
yet is to find the copyiipc hardware, an ISA card meant to copy ANYTHING and it
did.)
    In addition there were also a number of programs to remove the copy
protection, by defeating the INT 10 call to read this so called "bad" sector.
But were're talking the 80's here... this is why copy schemes died a pathetic
death.

                                                    Good luck,
                                                          -John

ps. however if you're really cool you can fire it up using DOSEMU, let the
program fail and cause a core dump and examine what its really trying to do
and put a jump instruction in... there was a "multi-session" program for DOS
which let you run multiple instances of DOS saving the memory of each one to a
file when you switched, many a program was defeated this way.


(Jehsom) writes:

>> I have an old DOS game on a copy protected diskette (720 kB). I thought
>> dd would allow me to make a backup -- no good. I'm guessing that I need
>> to change the floppy dirk parameters using setfdparm. Is this right?
>> Does anyone know how to get the needed disk parameters?

>One copy-protected program actually used the disk's serial number
>to verify that it was genuine. I don't know if dd actually reads &
>writes the serial number, but if it doesn't, you need to set it to
>the same serial number and it should work.
>Also, copy from the 720k floppy device in linux (forgot its name)

>Moshe

>--

>Geek code v3.12 (www.geekcode.com):
>GCS/E d- s+:-- a-- C++$ UL++>+++$ P+>++ L+++>$ E--- W+ N++ w--
>!O M-- V? PS+ PE Y+ !PGP t 5? X+ R- tv b- DI+ D+ G e>++ h r y

 
 
 

Using dd to copy copy-protected floppies

Post by Charles Sulliva » Wed, 05 Apr 2000 04:00:00



>I have an old DOS game on a copy protected diskette (720 kB). I thought
>dd would allow me to make a backup -- no good. I'm guessing that I need
>to change the floppy dirk parameters using setfdparm. Is this right?
>Does anyone know how to get the needed disk parameters?
>What should I do?

>Thanks,
>Duane Evenson

There were any number of schemes used to copy-protect diskettes,
most relying on some unusual sector arrangement or numbering.
One of the first and simplest (on Lotus 123) was adding an extra
(short) sector on one track, but later schemes were somewhat
more elaborate.

So you'd have to write a special formatter to duplicate what's
on the original disk, or else disassemble the program and hot
patch the part which looks for this unusual formatting.

As pointed out in another reply, there was one scheme which
used a laser to burn a defect into the media which the program
would then detect.  But I think this was only used for 5.25"
flops.  If you looked closely while rotating the diskette
media in its jacket you could spot the burn mark.

The old DOS CopyII PC program worked on most of the
software schemes at least.  It would not be able to handle
the burn mark except by patching the code (and it may have
done so).

Copy protection schemes went by the wayside because legitimate
users were greatly inconvenienced (or greatly at risk) while
the pirates had it easy.

 
 
 

Using dd to copy copy-protected floppies

Post by Ken Walt » Fri, 07 Apr 2000 04:00:00


On Thu, 1 Jan 1970 01:59:59, Duane Evenson


>I have an old DOS game on a copy protected diskette (720 kB). I thought
>dd would allow me to make a backup -- no good. I'm guessing that I need
>to change the floppy dirk parameters using setfdparm. Is this right?
>Does anyone know how to get the needed disk parameters?
>What should I do?

>Thanks,
>Duane Evenson

Many old DOS disks were protected by changing the placement of sectors
and writting bad sectors.  To copy these diskettes you need to copy
the
tracks exactly as is, including gaps, sector sizes and errors.

Ken Walter

Remove -zamboni to reply
All the above is hearsay and the opinion of no one in particular

 
 
 

Using dd to copy copy-protected floppies

Post by Duane Evenso » Sat, 08 Apr 2000 04:00:00


Doesn't dd ignore formatting questions? As I understand it, it copies the
data from start to finish, regardless of sector configurations, etc.

> On Thu, 1 Jan 1970 01:59:59, Duane Evenson

> >I have an old DOS game on a copy protected diskette (720 kB). I thought
> >dd would allow me to make a backup -- no good. I'm guessing that I need
> >to change the floppy dirk parameters using setfdparm. Is this right?
> >Does anyone know how to get the needed disk parameters?
> >What should I do?

> >Thanks,
> >Duane Evenson

> Many old DOS disks were protected by changing the placement of sectors
> and writting bad sectors.  To copy these diskettes you need to copy
> the
> tracks exactly as is, including gaps, sector sizes and errors.

> Ken Walter

> Remove -zamboni to reply
> All the above is hearsay and the opinion of no one in particular

 
 
 

Using dd to copy copy-protected floppies

Post by Dave Bro » Mon, 10 Apr 2000 04:00:00



>Doesn't dd ignore formatting questions? As I understand it, it copies the
>data from start to finish, regardless of sector configurations, etc.

No, dd uses the device definition of the driver.  Therefore, it is
restricted to the low-level format of the diskette, such as number of
cylinders, sectors/cylinder, etc.  It is true that dd does not care
about filesystem formats, etc, but only the raw device characteristics.

There are several formats available for diskettes, different from the
the 1.44 MB format of DOS diskettes.  To get an idea, look at /dev/fd*.

Some diskette copy-prevention schemes would skip a track, such that
normal copying would encounter a media error at that cylinder.  The boot
process of the diskette would modify the diskette driver to ignore the
missing track.

Dave Brown  Austin, TX