Checking the sources, it looks like bsdtar can read this using a command such 
as:

$ bsdtar xf archive.cpio  —option=cpio:pwb

bsdtar automatically recognizes and supports most modern cpio formats; the 
`cpio:pwb` option prompts it to use PWB file modes when extracting.

Tim


> On Dec 16, 2022, at 9:25 AM, Alice Lecinski <[email protected]> wrote:
> 
> Thanks Tim.  It'll be a fun afternoon. :-)
> Thanks for your help,
> --Alice
> 
> On Fri, Dec 16, 2022 at 10:21 AM Tim Kientzle <[email protected] 
> <mailto:[email protected]>> wrote:
> This appears to be a CPIO archive stored in the original cpio format 
> introduced as part of Programmer’s Work Bench (PWB), a variant of 6th Edition 
> UNIX.
> 
> The PWB format differed from that used in 7th Edition Unix in how it 
> represented file types.
> 
> The first file in this archive, for example, is stored with a file type of 
> octal 110644.  In the PWB format, this indicated a regular file with IALLOC 
> and ILARG flags set (neither of which is relevant for cpio purposes).  In 
> later 7th Edition, this is nonsense (a “regular file” that is also a “named 
> pipe”), which explains the errors you are seeing.
> 
> In short, you’ll need to find or write a program that can extract the PWB 
> format.  I’m not sure if GNU cpio can do this — it probably assumes “bin” 
> format is the 7th Edition Format.  I don’t recall if bsdcpio can extract this 
> or not — I’d have to check the sources.
> 
> Fortunately, cpio format is very easy to read.  It has a fixed-layout header 
> for each entry, followed by the filename and file contents.  So if you know 
> how to read binary data from one file and write it to another, you can 
> probably cobble up something workable in an afternoon.  The header details 
> can be found online: https://man.archlinux.org/man/cpio.5.en 
> <https://man.archlinux.org/man/cpio.5.en>
> 
> Tim
> 
> 
> 
> 
> 
> 
>> On Dec 15, 2022, at 10:16 AM, Alice Lecinski <[email protected] 
>> <mailto:[email protected]>> wrote:
>> 
>> Thank you so very much for your response.
>> 
>> Please find attached the results of:
>> od -xv --address-radix=d FILE_001 > V00063_hexdump.txt
>> 
>> Thank you,
>> Alice
>> 
>> 
>> On Wed, Dec 14, 2022 at 7:10 PM Tim Kientzle <[email protected] 
>> <mailto:[email protected]>> wrote:
>> Can you  provide a hex dump of the first 128 or so bytes of the archive?
>> 
>> Tim
>> 
>> 
>>> On Dec 14, 2022, at 12:40 PM, Alice Lecinski <[email protected] 
>>> <mailto:[email protected]>> wrote:
>>> 
>>> I have a very old cpio archive written in approximately 1990.
>>> It was most likely written on a VAX VMS (~linux) system.
>>> This is historical data and fairly important...
>>> 
>>> When I attempt to get the files using:
>>> cpio -iv --no-absolute-filenames --force-local --format='bin' < FILE_001 
>>> 
>>> I get the following output:
>>> cpio: ecl9w2: unknown file type
>>> ecl9w2
>>> cpio: g: unknown file type
>>> g
>>> cpio: ssss: unknown file type
>>> ssss
>>> cpio: t: unknown file type
>>> t
>>> wwww
>>> 5480 blocks
>>> 
>>> When I then do an 'ls', the 'wwww' file has been created.   But none of the 
>>> other files:
>>> 'ecl9w2', 'g', 't'
>>> exist.   
>>> The 'wwww' file is ascii and readable.   I know the 'ecl9w2' file is binary.
>>> 
>>> Any suggestions?
>>> Thank you,
>>> Alice
>>> 
>>> <><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
>>> Alice Lecinski                                
>>> Associate Scientist IV                    
>>> High Altitude Observatory            www2.hao.ucar.edu 
>>> <http://www2.hao.ucar.edu/>
>>> 
>>> HAO is a division of the National Center for Atmospheric Research,
>>> which is operated by the University Corporation for Atmospheric
>>> Research under sponsorship of the National Science Foundation.
>>> <><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
>> 
>> <V00063_hexdump.txt>
> 

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