John,

(a welcome to the HP3000-L family from my side, too :-)

>VAM Files -> Perm Files

It might work when accessing the MSG file in "copy mode", either
with a FILE equation like FILE vamfile;COPY or with the ;NOKSAM
option of FCOPY, which -I believe- causes FCOPY to use "copy mode".

 :copy vamfile,testA
 :file testA;copy
 :fcopy from=*testA;to=testA2;new

 :copy vamfile,testB
 :fcopy from=testB;to=testB2;new;noksam

 :listf test@,2

>Diff command in MPE

I also have seen the FILE TOO LARGE error when trying /bin/diff on
files that were MPE record oriented instead of bytestream. Taking
into account that Posix tools usually don't know how to handle any
type of file except for bytestream (which is their view of life),
I have usually worked aroung the problem by copying the files to
bytestream format and doing the diff on those...

 :/bin/tobyte "-at FILE1 /tmp/file1"
 :/bin/tobyte "-at FILE2 /tmp/file2"
 :/bin/diff "/tmp/file1 /tmp/file2"
 :purge /tmp/file#

Haven't tried all the above to verify, so your milage may vary.

Lars.