DGEN - The bad news, a complete description!
1st May 1999

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Firstly, IF YOU HAVE AN EMULATION WEB PAGE PLEASE INCLUDE THIS
TEXT WHEN YOU ANNOUNCE DGEN:

"The author of DGen, DTMNT (and the future DTMNT2) has had his partition
table corrupted by Windows NT4.0. If you believe you may be able to help,
please read the text file included with DGen for a description
of the problem."

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Since I'm busy at the mo it would be really nice to find a simple,
stress-free way to fix my computer!

IF YOU KNOW ANYONE WHO IS A PARTITION TABLE/HARD DISK EXPERT
PLEASE PASS THIS TEXT FILE TO THEM!

My e-mail as always is: dayvee@rocketmail.com
Of course please e-mail if you want more info than is below!

Short version - the facts:
--------------------------
Windows NT4.0 said it was installing on partition one and instead
messed up my partition table beyond recognition. Hard disk is
useless at the moment. Before I had 4+4 partitions and now I have 4
random partitions.

I know that the complete details are quite important if anyone
is going to suggest a fix to my problem, so here goes!
Thank you for reading this bit and if you can help I'd be really
grateful!

Long version - the facts:
-------------------------

I have a PentiumII-333mhz.

On the week of 28th April 1999 I had a rare bit of spare time and decided
to go about releasing DGen, mainly because I realised it didn't
compare too badly to existing Genesis emulators out there!
On the 28th I copied DGen to a floppy, and on the morning of the
29th tested it on a 15-bit display (colors were wrong annoyingly - my
code fix didn't work). This is the binary I am releasing as 1.00.
On the evening I decided to install Windows NT 4.0 on the first partition
on my hard disk (to test if my DirectX code works under NT).
I've done this before with no trouble, however that was probably
before I had seven other partitions!
It gave me a message about large hard drives not showing
all the space available, which seemed to be the usual FAT16/32 thing.
(I have been told about about a problem with WinNT claiming all your
hard-disk space if you answer an innocent looking "use all available
space" question. I was looking out for this question, and didn't
think I saw it. Even so, this may well be the cause.)

The installation program showed a copy of my partition table which I
recognised as normal, and I asked it to install in the first partition.

It moaned about something so I went back to partition 2 and
used Partition Magic 3.0 to make a NTFS file system on partition 1,
thinking that might make it happier. Nothing strange so far.

The partition table appeared in NT setup as normal except that
in partition 1 the NTFS file system was labelled as unrecognised.
I thought this was a bit ironic.
(I realised at this point that I could have formatted as FAT
 instead of NTFS.)

Here's the state of my disk partitons at this time (nothing wrong yet):

1. freshly made NTFS ready for NT                       roughly 300Mb
2. FAT32 called "WIN95_4"  with Windows95B installed    maybe   300Mb?
3. FAT32 called "NEWWIN95" with Windows95B installed    maybe   300Mb?
4. Extended partition
  (can't remember the exact order of the next four)
  5. Linux?
  6. Linux Swap?
  7. FAT32 called "DATA" containing all my work, DGEN, DTMNT,
     DTMNT2 progress                                    about 1000Mb?
     (I'm pretty sure this was partition 7 actually)
  8. ?

Switched Partition 1 as active again, and ran setup.
I picked the option to install in partition 1 and create a FAT
file system (by pressing 'C' I think?),
and about 20 secs later it said the file system was built.

I then did a "check" of some sort (20 secs?) and said it needed to
reboot my computer and go back into setup. When it rebooted it went
back to the same installation process I'd been through many
times already with one difference - the partition table it showed me
had only four entries and was in a ridiculous state - something like this:

1. (some random thing)   (some random value in Mb e.g. -17046325372Mb)
2. (some random thing)   (some random value in Mb e.g.   4537654368Mb)  
3. (some random thing)   (some random value in Mb e.g.            2Mb)
4. (some random thing)   (some random value in Mb e.g.3214231545345Mb)

Of course I can't remember exactly - I naturally panicked like a
b__tard and rebooted, and various other programs confirmed that
it really had written complete garbage into my partition table!
Here's what the various things I tried said:

Normal Boot Attempt:
COULD NOT BOOT [Active Partition]
Insert system disk

Linux Installation program
FDisk      - check partition table (loads of inconsistances)
Disk Druid - Two partitions with strange sizes

Linux Run attempt
hda0 hda1 (or whatever - only two partitions anyway)
Attempt to access beyong end of device
FAT (something)
Kernal panic blah blah

DOS/Win 95 no GUI, from a disk
Can't see anything but floppy drives

PQMAGICT from DOS
Error #105 and nothing printed - no useful options

FDISK from DOS - haven't dared to try it

What I think is wrong
---------------------
Obviously the partition table is ruined. I don't know how badly.
I would have thought its unlikely WinNT had time so delete all
2+ Gig of my hard disk in the 40 seconds or so it was using my disk,
but if anyone knows for sure please let me know.

What I'd like to do
-------------------

Get back the 1000Mb DATA partition - that's the only important partition.
I'd like to avoid opening up the case if possible. If the DATA partition
(partition 7 I'm pretty sure) is recovered it saves me a lot of trouble
reinstalling everything and redownloading DJGPP etc., and will rescue all my
emulation work (preliminary DTMNT2, DGen).

Failing that, if and when I'm sure that there is no way to recover
the partition, I'd like to have a way to make the computer work again.
I thought the BIOS was responsible for low level formatting the disk,
but I searched through and couldn't find any option to do this.

What people have suggested so far:
----------------------------------

1. Norton Disk Utilities - but can it really solve this
                        problem?
                        If you have details on how it can help please
                        e-mail me. (A which bits I need.)

2. A program called "FIX" (for DOS?)

3. Install another hard disk, install Norton or whatever and
use it to fix the other disk (I really don't like this idea, mainly
because I want to avoid opening the case).

********** What I'd like to know *************
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**** - Is my DATA partition (partition 7) still okay?
- Has WinNT touched partitions 2-8?
- Has WinNT trashed partitions 2-8 and if so how badly?
- How badly has WinNT changed my partition table?
  (e.g. are the label names still there?)
- Can my partition table be reconstructed and if so will it fix
  the problem?
- Is there a program to reconstruct a partition table,
  e.g. directly keying in byte by byte
  or e.g. by searching the hard disk for a FAT file system and
  then pointing at it?
- Can the problem be fixed from DOS or from a System disk which I
  can run directly? (no Windows remember! - that's the problem!)


I also have...
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A record of the CURRENT (i.e. wrecked) state of my partition table in
hexadecimal (0x200 bytes worth), so please e-mail if you can use this
information to repair it. Sadly I don't have a previous record of it
BEFORE it was wrecked.

Thanks for reading this! If you can help, please e-mail me!
Sorry for all your trouble!

Dave,
1 May 1999
dayvee@rocketmail.com
