[Coco] OS-9 HD backup

[Greg Law]

I used toolshed to extract the config.01 file from the disk image and 
confirmed that it is not compressed. I have no idea what created it, but it 
is essentially an uncompressed tarball created with something other than 
tar. The format seems to be $AA55 as a leader, the filename terminated with 
$0D, and a 16-byte header, and then the contents of the file. For example, 
the first couple of entries look like this:

AA 55 config/CMDS 0D
BF 00 00 59 03 05 07 2B
01 00 00 01 80 59 03 05

AA 55 config/CMDS/Basic09 0D
2F 00 00 59 03 05 07 2B
01 00 00 5A CC 59 03 05
... uncompressed contents of Basic09 ...

AA 55 config/CMDS/RunB 0D
2F 00 00 59 03 05 07 2B
01 00 00 2F 99 59 03 05
... uncompressed contents of RunB ...

It looks as if AA 55 is just a header identifier, the first byte of the 
header (BF and 2F) may be the file attributes, and bytes 13 and 14 (01 80, 
5A CC, and 2F 99) may be the file size. In other words, Basic09 is in bytes 
0044 through 5B10 for a total of 5ACC bytes. I suspect the file size for the 
directory entries could be the size of the directory at the time the backup 
set was created ($0180 / $20 = 12 directory entries).

The remainder of the bytes in the header seem to stay pretty much the same 
in the headers I've looked at.

Given the apparent simplicity of the format, it shouldn't take long to come 
up with something to extract all the files if it isn't BRU or some other 
known format.

Of course, given the caveat that this is based on a quick 5-minute peek 
through the file while I was eating supper.

-----Original Message----- 
From: Kandur
Sent: Wednesday, August 27, 2014 3:24 PM
To: CoCoList for Color Computer Enthusiasts
Subject: Re: [Coco] OS-9 HD backup

Gene, not sure, if Bru was available in 1989, when this backup was made.
It appears not being compressed, as the raw disk dump shows plain text, like 
this:

OSTerm V2.0.8 (C) 1989 by Vaughn Cato Copying permitted for non-profit use 
only To furthur the development of superior software, please contribute 
$10.00 to the author at: 1244 E. Piedmont Rd. NE. Marietta, Ga. 30062 
Special thanks to Phil Zeigler, who thought when I could think no longer.

Hex dump of the start of the file:
http://qdv.pw/coco/wp-content/uploads/2014/08/config-os9.jpg

Kandur

Wednesday, August 27, 2014, 11:41:27 AM, you wrote:
> On Wednesday 27 August 2014 14:06:01 Kandur did opine
> And Gene did reply:
>> My first batch of 28 floppy HD backup set had been restored
>> from 1989, thanks to Robert Gault's help and his endless patience.
>> The second  batch of 34 floppy HD backup set, may not have been
>> made by HDKIT, as it seem to have a different archive structure.
>> Please look at it, and let me know, if you can recognize it.
>> http://qdv.pw/coco/?p=289

>> Kandur

> Any chance of its being made by either of the 3 BRU's was destroyed by the
> apparent directory listing shown on that page.

> Since we've had several compression methods, I am wondering if perhaps it
> an HDKIT backup, but HDKIT was configured to use a different, perhaps more
> effective compression.  Its an avenue I'd explore.  One can often deduce
> tha compression used by looking at a dump of the first 32 bytes or so of
> one of the files, which often contains an identifier string.  dEd can show
> you that information if it can read it at all.

> Cheers, Gene Heskett
> -- 
> "There are four boxes to be used in defense of liberty:
>  soap, ballot, jury, and ammo. Please use in that order."
> -Ed Howdershelt (Author)
> Genes Web page <http://geneslinuxbox.net:6309/gene>
> US V Castleman, SCOTUS, Mar 2014 is grounds for Impeaching SCOTUS

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