🚀 go-pugleaf

In article <18148@umd5.umd.edu>, bleau@umdsp.umd.edu writes:
>...
>An ACP would be the best solution here. 

If you find one, please tell DEC so they can speed up VMS-POSIX file operations!

>Thirdly, in case the first two alternates are impossible or unworkable, is
>there possibly some intermediate format which would be easy to implement and
>write at the VMS end, and be easy to read at the UNIX end?  

Two spring immediately to mind: VMS Backup and unix tar. There are unix
utilities to read a backup tape, and VMS utilities to both read and write tar
tapes. Probably these wouldn't need any major changes to operate on a disk.
(Other archive formats are available on both systems: Zip, Zoo, etc., and can do
compression, if that's useful to you.)

I'd guess you could simply mount it /foreign on VMS and treat it pretty much
like a tape. You might have to tweak the qio's a little, or maybe not. I've
never done this on a disk. Similarly, on unix, you use the raw disk device name,
and you should be able to directly read raw disk blocks. 

I wouldn't be surprised if this would work with no software changes, with both
systems treating the raw disk basically like a tape, though, like I said, I've
never tried it.

>This format could
>be restrictive in the follwoing ways: ...

Either Backup or tar format would be less restrictive than what you said you'd
be willing to accept.

If you do have to write some software to access the raw disk, I'd write _only_
that. On VMS, write a file to disk copy routine and copy your chosen archive
format onto the disk. On unix, write a filter to read the disk and pass it to
stdout, and pipe it into tar or vmsbackup. (Dunno if vmsbackup will do this, tar
might be a better choice if you have to much with the software.)

>3) concatenate files into a single file are COPY it to a /FOREIGN mounted
>disk,
>   so it starts at block 0 and keeps going - already tried and proves too hard
>   for both ends to use, mainly because there is no demarcation between data
>   sets 

If that is that close to working, I'd say creating an archive and copying that
onto the disk is the way to go. Any archive that VMS can write and unix can read
should work. There is none that ships standard with both systems, but there is a
wealth of free tools to do the job.
--
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