It might be that your HDD is partitioned using GPT (GUID Partition Table) or MBR (Master Boot Record) and not APM (Apple Partition Map). I cannot see that from the above data, since it only lists the partitions and doesn’t tell anything about the partition table type.

Note that the bootdisk of all Intel Macs is certainly of the type GPT. Extra drives may be of any format.

When you want to recover a GPT, you might want to look at this thread on MacRumors Forum.

Disk /dev/disk1 – 1000 GB / 931 GiB – CHS 1953525168 1 1
Partition Start End Size in sectors
P HFS 409640 488790935 488381296
P DOS_FAT_32 488792064 977172479 488380416 [DOCS]
P DOS_FAT_32 977172480 1465552895 488380416 [PICTURES]
P DOS_FAT_32 1465552896 1953523711 487970816 [OTHERS]

Everything was bright until I received the message “Function write_part_mac not implemented” and I had to use pdisk.
I read carefully all your post in order to restored the missing partition.I open the terminal and when I reached 11) from your to do list this was what i received:

Last login: Sun Feb 7 14:16:21 on ttys000
Macintosh-2:~ M$ sudo pdisk
Password:
Top level command (? for help): L
pdisk: No valid block 1 on ‘/dev/rdisk1′
Floating point exception
Macintosh-2:~ M$

..and once more I’m looking to a brick wall without any clue what to do.
I do not know which partition is missing and how do I acess to my partition table in pdisk. I would desperately appreciate any help.
I’m using a Intel/mac and I hope that this is not a problem..

This saved my 500gb usb maxtor hdd!! All my photos, everything was there!!
I really thank you!!

It took me 2 days to find you, so please publish this everywhere!!

Thanks again!!!

I tried booting a Mac install disk and “repairing” the disk. It checked the partition map, which was fine, but did not repair the boot block. I tried installing and choosing the custom install to install “nothing” but that was no help either.

Finally I decided I had to do it by hand. I found a detailed description of what goes in the boot0 block of an Apple Partition Map (APM).

I booted the Mac into target-disk-mode (hold down ‘T’ when booting), then used a firewire cable to connect the drive to another computer. Using a hex editor (like one of these http://en.wikipedia.org/wiki/Disk_editor) I hand entered hex values as follows:

45 52 (APM boot block signature)
02 00 (block size=512 bytes in hex)
xx xx xx xx (size of entire hard disk in blocks in hex)
00 00 00 00 00 00 00 00 (reserved all zeros)
00 00 (NO special device drivers)
00 00 00 00 00 00 00 01 (empty device driver entry)

Then I booted the Mac, and it worked!

Note: to find the size of your hard disk, boot with the Mac install CD, open a terminal and use: diskutil list, and diskutil info /dev/disk0

Note: to convert the size into hex, use a calculator that can do it for you or open a terminal and use “bc” : ibase=10; obase=16; 500000000 (or whatever your size is)

Note: While in the hex editor I looked at the first few 512 byte blocks of the disk. I had an MSDOS block0 with the text “Invalid partition table. Error loading operating system. Missing operating system”. That didn’t belong there, that was the cause of my problem. I also had a good Apple Partition Table in the next four 512-byte blocks. Each one started with the characters “PM”, which told me they were undamaged.

Again, read the link above that describes APM in detail for better understanding.

In my case, the APM was on an external disk without a bootable partition on it, so I didn’t have the same problem you did.

Would you please share your solution, so others can benefit from it?