Create ISO > 700Mb to fit on 80min CD

I have downloaded some ISO’s which contain > 1 Gb of data, and burn perfectly on an 80min CD. (largest contained 2332Mb !!)

Could anyone please enlighten me on the method used to make such an ISO.


I have downloaded some ISO’s

This board doesn’t support illegal stuff!

:cool: I very carefully avoided mentioning programs and as far as I’m concerned it’s a legit question and has nothing to do with what I do or don’t download:a

Originally posted by Andareed
This board doesn’t support illegal stuff!

there are lots of Legal ISOs you can download… He may have even bought them, Microsoft distribute stuff through ISOs

It is quite simple to accomplish. Usually you will see this method on os’s that can boot various versions of the same os. Generally, different versions share many common files. All of these common are physically located on the cd once. Each version is in its own directory and each directory just links to the same files multiple times.

:cool:Try, and if you use it, buy it !! Which I have been doing for the odd 18 years.

Case in point: 5-in-1: do I upgrade this particular program as Pro or Standard, what are the features I would never use?

I understand the principle of common files, that would mean that if I unpack the ISO (700Mb) to the hdd, I should also be able to re-assemble it in WinIso to the same size; result 1100Mb.

So my question is still, what method or program was used to make an ISO of “only” 700Mb

I have no idea what programs you could use to do this. It would be tedious, but possible, to do this manually.

The secret behind <1GB on a 700MB CD is that duplicate files are stored only once. The other identical files are just links.
There are no limit on how much data to store on a CD, exept the size of the partition you create the image from! :smiley:

As far as I know there are only 2 applications that has this feature.
Both are from Microsoft and only for internal use!
cdimage and oscdimg with this feature:

CDIMAGE 2.47 CD-ROM and DVD-ROM Premastering Utility
Copyright © Microsoft, 1993-2000. All rights reserved.
For Microsoft internal use only.

Usage: CDIMAGE [options] sourceroot targetfile

-o optimize storage by encoding duplicate files only once

These programs are Warez, so dont bother to as where to get them.