XYMer's Home away from Home

When http://bbs.xlr8yourmac.com is down (i.e. always)
It is currently Sun Jun 25, 2017 4:21 pm

All times are UTC - 8 hours




Post new topic Reply to topic  [ 26 posts ]  Go to page 1, 2  Next
Author Message
PostPosted: Sat Apr 07, 2012 9:50 am 
Offline

Joined: Sun Dec 04, 2011 9:53 am
Posts: 321
I've got a .iso image that takes up over 500 MB, but the contents are only about 130 MB, so I want to shrink it down to the actual size. Toast 5.2.3 will run and mount the .iso image, but I can't seem to find a way to drag and drop the actual files in it to a new disk image, or shrink the .iso to the real size of the files. And Toast says it can't save files in Mac OS Standard format, which is the format of the original .iso.

So, how can I create and/or shrink this way too big .iso in Mac OS 8 or 9, while preserving the format?


Top
 Profile  
 
PostPosted: Sat Apr 07, 2012 11:21 am 
Offline
Benevolent Dictator
User avatar

Joined: Mon Apr 21, 2008 2:03 am
Posts: 14485
Hmmm,

What format is the original ISO?

Can you make a Blank 140 MB R&W ISO somewhere and copy it over to copy the files over once both are mounted?


Top
 Profile  
 
PostPosted: Sat Apr 07, 2012 11:59 am 
Offline

Joined: Sun Dec 04, 2011 9:53 am
Posts: 321
From what I can tell, the original ISO is in Mac OS Standard format, which Toast 5.2.3 can't create. But that begs the question of how Apple or anyone else created images in Mac OS 7, 8, and 9 to make CDs for their own installation disks.

Anyway, I tried using Disk Utility in OS X to create a new blank image of 140MB, then mounted the original ISO in the Finder and copied over the files. That seemed to work, but I don't know if the proper format and bit bundles were preserved, since the System Folder won't work if you just Copy/Drag it from one place to the another in Mac OS X. Then I unmounted both and had a new .dmg, which I converted to CD/DVD Master in Disk Utility.

So, do you think this will actually be a viable, working ISO image that can be burned to CD and then used to boot a classic Mac or install the OS on a classic Mac? I can't test it yet since I'm waiting for a new CD drive for my vintage Mac to arrive (hopefully for free).


Top
 Profile  
 
PostPosted: Sat Apr 07, 2012 12:09 pm 
Offline
Benevolent Dictator
User avatar

Joined: Mon Apr 21, 2008 2:03 am
Posts: 14485
I'm not sure if it's viable or not.

So, this is supposed to be a bootable CD?

Why do you want to reduce the size?


Top
 Profile  
 
PostPosted: Sat Apr 07, 2012 12:18 pm 
Offline

Joined: Sun Dec 04, 2011 9:53 am
Posts: 321
Yes, it should be bootable. The original ISO file was over 500 MB, and this version of Mac OS doesn't take up anywhere near that amount of space. The actual files total up to 126.xx MB, so that's why I want to reduce the size.


Top
 Profile  
 
PostPosted: Sat Apr 07, 2012 12:33 pm 
Offline
Benevolent Dictator
User avatar

Joined: Mon Apr 21, 2008 2:03 am
Posts: 14485
What are you going to do with the left over space on the CD?


Top
 Profile  
 
PostPosted: Sat Apr 07, 2012 12:38 pm 
Offline

Joined: Sun Dec 04, 2011 9:53 am
Posts: 321
Nothing. I'm trying to make archive CDs of each version of Mac OS, so the only thing on each one will be a separate version of Mac OS and nothing else.


Top
 Profile  
 
PostPosted: Sat Apr 07, 2012 1:22 pm 
Offline
Benevolent Dictator
User avatar

Joined: Mon Apr 21, 2008 2:03 am
Posts: 14485
In that case you've really lost me now!???

One OS per CD, right?


Top
 Profile  
 
PostPosted: Sat Apr 07, 2012 1:29 pm 
Offline

Joined: Sun Dec 04, 2011 9:53 am
Posts: 321
Yes, one OS version per CD.


Top
 Profile  
 
PostPosted: Sat Apr 07, 2012 2:08 pm 
Offline
Benevolent Dictator
User avatar

Joined: Mon Apr 21, 2008 2:03 am
Posts: 14485
OK, so what are you planning to do with the rest of the space on the CD IF you can reduce it?


Top
 Profile  
 
PostPosted: Sat Apr 07, 2012 2:11 pm 
Offline

Joined: Sun Dec 04, 2011 9:53 am
Posts: 321
Leave it blank, just like any other Mac OS Install CD.


Top
 Profile  
 
PostPosted: Sat Apr 07, 2012 2:29 pm 
Offline
Benevolent Dictator
User avatar

Joined: Mon Apr 21, 2008 2:03 am
Posts: 14485
Then there's really no reason to change the size, maybe a tiny bit of time to write the extra 370 MB, but likely not even that, as likely that is just written to the Disc structure, not really the Disc.

I don't know about OS CDs, but some CDs write raw data to those blank sectors that is only read by the Install App, as they aren't listed as files, they don't show using any space.


Top
 Profile  
 
PostPosted: Sat Apr 07, 2012 2:41 pm 
Offline

Joined: Sun Dec 04, 2011 9:53 am
Posts: 321
BDAqua wrote:
Then there's really no reason to change the size, maybe a tiny bit of time to write the extra 370 MB, but likely not even that, as likely that is just written to the Disc structure, not really the Disc.

Well, there's no point in using up that much space on a CD, especially when you're storing these "in the cloud" as another backup method. That just takes longer to upload, even if you compress it first.

Quote:
I don't know about OS CDs, but some CDs write raw data to those blank sectors that is only read by the Install App, as they aren't listed as files, they don't show using any space.

True, but the OS version right after this one doesn't even take up nearly that much space, so there can't be anything else written on the disc.


Top
 Profile  
 
PostPosted: Sat Apr 07, 2012 2:45 pm 
Offline
Benevolent Dictator
User avatar

Joined: Mon Apr 21, 2008 2:03 am
Posts: 14485
Have you tried making a compressed dmg out of them/one?


Top
 Profile  
 
PostPosted: Sat Apr 07, 2012 2:59 pm 
Offline

Joined: Sun Dec 04, 2011 9:53 am
Posts: 321
No, because these are classic Mac OS versions, so I've read that if you try to make a .dmg from it, all you'll accomplish is something that won't boot, because of the differences between Mac OS and Mac OS X. Don't want to risk that.


Top
 Profile  
 
PostPosted: Sat Apr 07, 2012 3:09 pm 
Offline
Benevolent Dictator
User avatar

Joined: Mon Apr 21, 2008 2:03 am
Posts: 14485
Ah yes, I see.

Have you tried ZIPping one or TARing one to see online storage size?


Top
 Profile  
 
PostPosted: Sat Apr 07, 2012 3:20 pm 
Offline

Joined: Sun Dec 04, 2011 9:53 am
Posts: 321
After shrinking all the space off the original ISO, it's 140MB in size; if I .zip it, it becomes 88MB in size. As long as it remains an ISO image (that hopefully wasn't corrupted in the process of opening it in Mac OS X and copying the files to the new one), there shouldn't be a problem. But if I start messing around with it in Mac OS X and then try to use it, I'm SOL.


Top
 Profile  
 
PostPosted: Sat Apr 07, 2012 3:28 pm 
Offline
Benevolent Dictator
User avatar

Joined: Mon Apr 21, 2008 2:03 am
Posts: 14485
Well, I'll be anxious to know if OSX did mess with them.


Top
 Profile  
 
PostPosted: Sat Apr 07, 2012 3:38 pm 
Offline

Joined: Sun Dec 04, 2011 9:53 am
Posts: 321
So will I. But I won't find out until my new CD drive arrives, and I haven't found one that meets my needs yet.

Time to go watch 60 Minutes and The Closer.


Top
 Profile  
 
PostPosted: Sun Apr 08, 2012 6:23 pm 
Offline
User avatar

Joined: Thu May 15, 2008 8:13 pm
Posts: 9269
Location: Caught between the moon and NYC
Shouldn't you be creating .toast files and not .iso files? .toast images can contain HFS/HFS+ partitions while ISO is, well, ISO. You can make hybrid ISO9660/HFS discs but I don't think they're bootable, at least under earlier OSes like OS9.

Back when I wanted to make a bootable image I would create a partition on a disk, get it setup however I wanted, made sure it was bootable by booting off it, then created a .toast image from that partition. At least that's what I remember doing, but I know for a fact that .ISO is not just any old file format, it's ISO9660.

.toast images created in older versions of Toast can be read by newer Toast versions, at least up to 10 or so (presumably it's compatible with newer versions too, I just haven't tested it), so they are futureproof to at least 10.7.


Top
 Profile  
 
PostPosted: Sun Apr 08, 2012 7:01 pm 
Offline

Joined: Sun Dec 04, 2011 9:53 am
Posts: 321
Actually, Toast files are .iso files; they're identical except for the .toast extension; same with .cdr files being .iso files, but with a different extension. The problem you have for Mac OS versions prior to Mac OS X is that unless you create an .iso file, the resource fork of the System Folder will be gone, so it will not be blessed when you install it, so it will never boot; no amount of tinkering after the fact will make it boot.

Depending on the size and the version of any application (including Mac OS), your choices for preserving the resource fork comes down to using the right version of Disk Copy to make floppy disk images, or a compatible version of Toast to make .cdr, .iso, .toast files.

It's complicated.


Top
 Profile  
 
PostPosted: Sun Apr 08, 2012 7:33 pm 
Offline
User avatar

Joined: Thu May 15, 2008 8:13 pm
Posts: 9269
Location: Caught between the moon and NYC
An .iso file is not just a .toast file. ISO9660 ≠ HFS/HFS+. No, really, I worked with the guy who created the very first HFS/ISO9660 implementation. They're not the same thing.

If you have a .toast file that contains ISO9660 data then you can convert that image to an .iso file without losing data. The same isn't true if it contains HFS/HFS+ data as you've already illustrated, since ISO9660 is only for data forks. I think you're confused because HFS/ISO9660 hybrid discs which can contain both ISO9660 and HFS data, with unique data stored in separate partitions on the disc, but if you convert a .toast image that contains both to .iso you lose the HFS data.

In addition the .toast image, as in the file itself, is purely a data fork, any the resource fork for the image file can be discarded without harming the actual image, because the resource forks of the contents are not stored in the resource fork of the .toast file.

Furthermore as for the topic of bootable images, I already explained the best method to use to ensure the resulting image will be bootable. If you just drag a bunch of files into a data CD in Toast then, yes, the result won't be bootable, regardless of whether you choose HFS or ISO9660 as the disc format. If you want to maintain compatibility then HFS is perfectly fine since Apple shows no sign of discarding it, but OS7/OS8/OS9 of course support HFS.

I used to create master discs for a CD-ROM publisher (who, for a time, had the best selling CD-ROM game in the US), who produced Mac, PC, and (eventually) Mac/PC versions of their titles.


Top
 Profile  
 
PostPosted: Mon Apr 09, 2012 6:15 am 
Offline

Joined: Sun Dec 04, 2011 9:53 am
Posts: 321
Quote:
If you have a .toast file that contains ISO9660 data then you can convert that image to an .iso file without losing data. The same isn't true if it contains HFS/HFS+ data as you've already illustrated, since ISO9660 is only for data forks. I think you're confused because HFS/ISO9660 hybrid discs which can contain both ISO9660 and HFS data, with unique data stored in separate partitions on the disc, but if you convert a .toast image that contains both to .iso you lose the HFS data.

Hmm…that just seems to be adding more complexity and confusion to the mix. I've read that a common way of compressing files (.zip) will strip the resource fork from the Mac OS System, which is what it needs in order for the System Folder to be blessed after you install it. But the only "safe" way of doing that is to create an .cdr/.iso/.toast image first, in a compatible OS; i.e., not Mac OS X, or use .sit.

Mac OS 7 used the Mac OS Standard format, which prior versions of Toast don't seem to be able to create, so that leaves doubt in my mind as to whether using any of those (Toast 4.x or 5.x) would accomplish what I need—a bootable Mac OS 7 disc. Even worse is that some of the .iso images I've made warn me when I try to open them that they may be damaged, yet they appear to be perfectly fine if I continue with the opening process. One says the image is not recognized, which is puzzling, because I can mount it with Toast and it appears to be okay. How can I tell, other than trying to install and boot from it?

It would be nice if someone had a definitive FAQ-type of document that gave very specific details of the best way to do this. Since I'm trying to preserve legacy software for the future (and get it off my hard drive), it would be nice if I knew the correct way to do it so that it still works.


Top
 Profile  
 
PostPosted: Mon Apr 09, 2012 12:20 pm 
Offline
User avatar

Joined: Thu May 15, 2008 8:13 pm
Posts: 9269
Location: Caught between the moon and NYC
There is a way to create a .zip that contains the resource fork, and OSX (up until 10.5 at least) will create .zips in this fashion. It basically creates a 2nd file for the resource fork and then recombobulates the two files on the extract. As I recall it creates a whole separate resource fork folder when you extract the zip on a PC, which is how to know when a zip was created on a Mac.

As for the system folder to be blessed, you can't just extract a system folder out of an archive to a disk and have it to work. You need to bless the system folder afterwards, using a tool like System Picker... or by dragging the Finder out of the System Folder then dropping it back in. Note the latter trick tends to not work if you have multiple system folders on a disk (which is why SP was created).

If you want a bootable image that you can burn to a disc and have it function, creating it on a partition, making sure it's bootable by booting off it, and then restarting into another environment and burning that partition to an HFS Standard .toast image is really the way to go. It saves creating coasters, and you can customize the OS environment.

Obviously the wrinkle is that HFS+ is only bootable back to OS8 or so, so for anything earlier you have to go with HFS Standard, which means booting into OS8 / OS9 and performing all these operations in it. I don't remember being able to create HFS volumes in 10.0 or 10.1, but I could be mistaken... it was a long time ago, and changes came quick back in the early days of OSX.

As for Toast support, HFS Standard discs could be created all the way up to Toast 10, but the functionality was removed from 11:
http://www.macintoshgarden.org/forum/to ... s-standard

IOW, I really think you're going to create more headache for yourself trying to create bootable .iso images for old MacOS versions. ISO9660 support under OS9 was fairly solid but limited in what features were supported, and hybrid discs have always been a bit of a kludge.


Top
 Profile  
 
PostPosted: Mon Apr 09, 2012 12:44 pm 
Offline

Joined: Sun Dec 04, 2011 9:53 am
Posts: 321
Quote:
As I recall it creates a whole separate resource fork folder when you extract the zip on a PC, which is how to know when a zip was created on a Mac.
If you do that with a Mac OS install, it won't work when you try to decompress it. I've actually downloaded some things to test that and in every case, you couldn't mount the uncompressed archive because it had been bastardized on a PeeCee.
Quote:
As for the system folder to be blessed, you can't just extract a system folder out of an archive to a disk and have it to work.
I don't want to drag and drop a System Folder; I'm creating archives from actual Mac OS system install discs, so it will be installed and blessed when you restart. But I want to save space by compressing them, without losing the ability to open the archive later, burn it to a CD or DVD, and use it to install the OS.
Quote:
If you want a bootable image that you can burn to a disc and have it function, creating it on a partition, making sure it's bootable by booting off it, and then restarting into another environment and burning that partition to an HFS Standard .toast image is really the way to go. It saves creating coasters, and you can customize the OS environment.
I have Toast 5.2.3 running in Classic to create .iso/.toast images, but it doesn't give me any choice as to what format to use, so I don't know what it's doing. I'm still very curious to know how Apple created Mac OS install CDs if they didn't have Toast or any other known software to preserve everything they needed in the resource forks.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 26 posts ]  Go to page 1, 2  Next

All times are UTC - 8 hours


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron
Powered by phpBB® Forum Software © phpBB Group