[Coco] Princeton files

John E. Malmberg wb8tyw at qsl.net
Sun Oct 12 00:58:00 EDT 2003

Bob Devries wrote:
> I'll be working towards putting all this stuff onto CDROM.
> Any ideas on how I should go about this would be welcome.
> Two important issues occur to me:
> 1. filename lengths

That is easy.  ISO9660 restricts filenames to 8 characters with a 3 
letter extension.  It also restricts them to 8 directory levels.

There have been many extensions to the standard, but the above is what 
you can expect any platform to be able to read.

> 2. attributes.

ISO9660 supports many file attributes.  Unfortunately since most 
operating systems do not, most of the mastering software I am aware of 
will not allow you to set them.

> My idea is to create a directory on the HD of my COCO3, and put everything
> in there in the same way as on my PC HD, and then do a "ls -lR >index.txt".
> That will at least give an idea of what the directory structure looked like
> originally.

What would probably be good enough is to put the directory tree created 
by each "disk" in a ZIP archive and put the resulting archives on an 

> Ideally, of course, it would be great to make an OS-9 file system CDROM, but
> (a) I don't have any idea of how to do that, and (b) I don't have a CDROM
> drive on my coco3 nor my MM/1 to read it.

The ISO file system starts at 64 * 512 bytes.  While you can build an 
dual format ISO volume that only has one copy of each file that both 
directory trees are linked to, the mkisofs program seems to only support 

The procedure is to first put all the files in a staging directory on 
the system you are creating an ISO master on, and then create the ISO image.

Then you create a logical disk container file the size of the CD-ROM 
that you will be burning.

You overlay the ISO master over the container file, and reset the EOF 
marker on the container file to be where it is supposed to be.

Then you use a program to initialize the container file as an OS-9 (or 
other) volume, but mark the sectors starting at 64 * 512 bytes through 
the size of the ISO image as bad, so the intializer will not touch them.

[Other ways probably can be done for this]

Keep in mind that CD-ROMS are blocked at 2048 byte sectors, so all files 
are a multiple of that size.  That can limit the amount of files.

Now that is how to make a dual format volume.  How to get the COCO to 
read it in either format is a different story.

wb8tyw at qsl.net
Personal Opinion Only

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