[Techtalk] Unreadable(?) pdf files

[David Sumbler]

I have a rather old CD-R with a number of pdf files on it.

When I try to open any of these files with Adobe Acrobat 9, evince
v.3.4.0 or Gimp v.2.6.12 I see what seems to be the appropriate number
of pages, but all of them are blank.

If I open them with emacs, there is clearly a lot of data there.  In
emacs, one of these files (chosen arbitrarily) begins like this:

%PDF-1.2
%âãÏÓ
4 0 obj
<<
/Type /Page
/Parent 2 0 R
/Contents 5 0 R
/MediaBox [0 0 596 842]
/Resources <<
/ProcSet [/PDF]
/XObject << /PS6 6 0 R >>
>>
/Annots [7 0 R ]
>>
endobj
A
/Length 60
>>
stream
\200^LE\303^H$^P at 0\201\301F^PxL^TA^B\205B\341^P\250dP\306m

and so on for 100s of lines.

I have searched for ways of converting old pdf files to later versions,
but (a) I haven't managed to find any, and (b) several sites suggest
that Acrobat, at least, ought to be able to read files from earlier
versions without conversion.

Can somebody think of a way of rescuing these files and converting them
to something usable?

David