[rescue] Getting QIC tapes images

[Alan Perry]

I have the green plastibands and the clear bands. I have found that the 
clear bands have too much tension and can lift material from the tape. 
The tension of the green bands vary and it seems like there is a window 
where they work best.

The tapes came with a Sun 3/160 based Model 32, and some are clearly for 
it. My goal is to restore the CADDStation and I hope all of the software 
is there on the tapes.

Where can one find copytape for SunOS?

I was able to use tapetool to extract a file called tapedir from two 
different tapes

alan

On 5/14/26 11:35 AM, Clem Cole wrote:
> First, what are you using for bands?  (size and manufacturer).
>
> With regard to the tape itself, given that these are old tapes, assume 
> you will get one shot in the transport.  So I >>highly<< recommend 
> using the old 1985 copytape utility from the USENET (pdf of its man 
> page of the command and the format it writes attached), and creating a 
> tape image you can decode without needing to touch either the tape or 
> the transport.   If you don't have it, send me an email off-list, and 
> I'll be happy to provide it to you.
>
> copytape will attempt to read 262144 (256K) bytes at a time.  On a QIC 
> drive, which has fixed-size (512-byte) records, that will equate to 
> 512 blocks (on a 9-track, which used variable-sized records, each 256k 
> read, will return as many bytes as were written on that tape record, 
> which canbe a small integer to no more than 65536 (64K bytes).  
>  Copytape will read tape marks. Tape "files" are delineated by tape 
> marks.  On drivers that were written properly, the last "tape file" 
> will have a second tape mark [/i.e./, two in a row] to delineate EOT. 
> Note that many of the QIC drivers do not do that (and neither did 
> Ken's original 9-track tape driver for Fifth Edition and IIRC Sixth, 
> but by then a number of us had rewritten to 9-track drivers to be much 
> smarter, but I digress)
>
> Once you have a copy of the tape in "copytape" format, you can decode 
> it much more easily.
>
> As for the format itself, it depends on which Computer Vision system 
> wrote it.   Their early systems were based on DG Novas and ran RDOS 
> (similar to DEC's RT11).  From the late 70s until the mid 1980s, they 
> replaced RDOS with their own OS called CGOS (Computervision Graphics 
> Operating System), and by the late 80's, early 90's, they had ported 
> their CADDS system to run on UNIX and started shipping it on Suns. 
> Finally, they got bought by Prime, and then moved it again to PRIMOS.
>
> Given that this is a QIC tape, the time frame says either late CGOS or 
> SunOS, although Prime might have supported QIC; I never saw anything 
> but 9-track on their systems.
>
> So ... if it was written on an early CV system, it is likely to be in 
> what DG called MTIO format or possibly in the DG backup format. Data 
> General’s RDOS natively used raw, streaming sequential blocks without 
> a complex, metadata-heavy file system structure, such as ANSI labeled 
> tapes (DEC often used a superset - embrace and extend - ANSI tape 
> format).   I don't know what CGOS used, but I suspect it was similar 
> to the DG style.   If it was written on a Sun or other UNIX box, it is 
> likely to be TAR (hopefully) or CPIO. If the latter, there is a slew 
> of different CPIO on tape formats - this is historical becauseit was 
> created for PDP-11s and was a binary format. It could also be one of 
> the many UNIX backup formats, so you will need to do a little 
> examination to determine which one.  Modern versions of the original 
> V7 Unix file(1) >>might<< be able to identify the format. Finally, 
> like DG, Prime opted not to use DEC-style (pseudo-ANSI) labeled file 
> structures natively. Instead, they also created their own proprietary, 
> streaming binary format deeply tied to PRIMOS’s unique disk 
> architecture and character encodings.  I've never seen documentation 
> on this format.
>
> On Thu, May 14, 2026 at 9:44 AM Alan Perry via rescue 
> <rescue at sunhelp.org> wrote:
>
>     I seem to have found a working combination of drive and
>     replacement's bands to be able to get images of the dozens of
>     Computervision install tapes that I have.
>
>     They are QIC-24 from the late 80s and aren’t in the “collection of
>     tar files” format that I usually use mt fsf and dd to read. Each
>     tape starts with a file with a “tapedir” record with permission
>     and other stuff, followed by a bunch of records that look like a
>     number followed by a topic or title. What am I looking at and what
>     do I use to get the info off of the tape?
>
>     alan
>
>
>
>
>     _______________________________________________
>     rescue list - http://sunhelp.org/mailman/listinfo/rescue_sunhelp.org
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://sunhelp.org/pipermail/rescue_sunhelp.org/attachments/20260515/8b0e05dd/attachment.html>