Previous Thread
Next Thread
Print Thread
Joined: Nov 2003
Posts: 186
Likes: 1
P
PhillHS Offline OP
Senior Member
OP Offline
Senior Member
P
Joined: Nov 2003
Posts: 186
Likes: 1
Hi All,

I have a CHD file (RM nimbus hard disk), that contains a DOS FAT16 filesystem. The filesystem contains some files that I want to extract so I use the following :

chdman extractraw -i windows.chd -o windows.raw

Then under linux (on WSL2) I mount it with losetup :

losetup -f windows.raw -o 0x400
mount /dev/loop0 /mnt2 -r -t msdos

All appears well, however there are files on the windows chd that are *NOT* on the extracted raw file. So where are they?
Is this the right way of geting a full dump of what's currently on the hard disk?

Cheers.

Phill.

Joined: Mar 2001
Posts: 16,960
Likes: 76
R
Very Senior Member
Online Content
Very Senior Member
R
Joined: Mar 2001
Posts: 16,960
Likes: 76
Was the CHD created with -c none so it's not compressed? Otherwise you probably have an associated overlay image in your diff/ directory, and you'll need to merge that with the CHD.

Joined: Nov 2003
Posts: 186
Likes: 1
P
PhillHS Offline OP
Senior Member
OP Offline
Senior Member
P
Joined: Nov 2003
Posts: 186
Likes: 1
Ahh there is indeed a chd in the diff directory, so how do I go about merging them?

More importantly is there a way of getting it to not write a diff, but write it to the original?

Cheers.

Phill.

Joined: Feb 2004
Posts: 2,447
Likes: 150
Very Senior Member
Offline
Very Senior Member
Joined: Feb 2004
Posts: 2,447
Likes: 150
You have to convert it to an uncompressed CHD, applying the diff. It will write directly to uncompressed CHDs.

Joined: Nov 2003
Posts: 186
Likes: 1
P
PhillHS Offline OP
Senior Member
OP Offline
Senior Member
P
Joined: Nov 2003
Posts: 186
Likes: 1
Indeed, but what chdman commands do I need to do that?

Right it seems that :

chdman extractraw -i windows.diff -ip windows.chd -o windows.raw

Did what I needed to merge and extract. Now to create an uncompressed chd from that.....

Cheers.

Phill.

Last edited by PhillHS; 10/16/21 05:36 PM.
Joined: Mar 2001
Posts: 16,960
Likes: 76
R
Very Senior Member
Online Content
Very Senior Member
R
Joined: Mar 2001
Posts: 16,960
Likes: 76
First up, you can actually use raw images with most MAME hard disks devices now (I put it in I think over a year ago now). .hd, .hdv, or .hdi are all accepted to mean "raw image", although for IDE it will try to auto-compute the geometry which may not be correct. SCSI disks don't have that problem.

To create an uncompressed CHD, you do the same thing as for a regular CHD but add "-c none", meaning compression type none.


Link Copied to Clipboard
Who's Online Now
3 members (robcfg, Dorando, 1 invisible), 22 guests, and 1 robot.
Key: Admin, Global Mod, Mod
ShoutChat
Comment Guidelines: Do post respectful and insightful comments. Don't flame, hate, spam.
Forum Statistics
Forums9
Topics9,158
Posts119,916
Members5,034
Most Online1,283
Dec 21st, 2022
Our Sponsor
These forums are sponsored by Superior Solitaire, an ad-free card game collection for macOS and iOS. Download it today!

Superior Solitaire
Forum hosted by www.retrogamesformac.com