These files were restored from Andrew McKendrick's paper tapes.

They are mostly of the KDF-9 Imp compiler, which was written in
Imp (which was much closer to Atlas Autocode back then) but with
much embedded assembly code.

Note that 'IMP9 compiler tape 1 imp' uses %CAPTION to print text
messages, which is pure Atlas Autocode.  Whereas 'IMP PS Program'
uses %PRINTTEXT which was the early Imp equivalent.  (Later Imp
programs used a string procedure "Print string()", but this was
before David Rees had added strings to the language).  Also variables
such as "N'" in "N=0 ; N'=0" are classic Atlas Autocode.  There
is very little in this that is specifically Imp - in fact I am
beginning to suspect that this is the very first Imp compiler
which is in the process of being bootstrapped through Atlas Autocode,
and that the earlier compilers (such as for the Atlas itself)
were actually AA compilers even though we may have started
called them "Imp" at Edinburgh.

This is the oldest Imp compiler known to still exist.  We have not
located any copies of the Atlas Autocode compilers, although we
do have the Atlas Autocode manual, which will come in useful later
as it describes the character set encoding used on the Atlas.

The .asc files have had the parity bit stripped coming off the paper
tape reader, and NULs removed.  The .bin files are untouched.

The file names are what was written on the paper tape.

These files were restored by a Herculean effort from Ian Young and
Chris Whitfield which is documented elsewhere.

 Name                               Last modified      Size  Description
 imp9.asc                           2008-10-13 09:02   79K  
 IMP9 compiler tape 3 imp.asc       2008-10-13 09:01   29K  
 IMP9 compiler tape 2 imp.asc       2008-10-13 09:02   27K  
 IMP9 perm tape 1 imp.asc           2008-10-13 09:01   24K  
 IMP9 compiler tape 1 imp.asc       2008-10-13 09:01   23K  
 IMP9 perm tape 2 imp.asc           2008-10-13 09:02   22K  
 ABC PS table.asc                   2008-10-13 09:01   10K  
 PPS ISO ABC.asc                    2008-10-13 09:02   10K  
 assembler.txt                      2009-02-24 20:19  9.5K  
 IMP PS structures 7.asc            2008-10-13 09:01  6.8K  
 IMP PS structures 6.asc            2008-10-13 09:01  6.8K  
 IMP50 Table PS part 2.asc          2008-10-13 09:01  3.6K  
 IMP9 PS Program.asc                2008-10-13 09:02  3.6K  
 diags abcd 10 may.bin              2008-10-13 09:02  2.9K  
 ABC progs 5 may 68.bin             2008-10-13 09:02  2.9K  
 ABC dump 25 July 68.bin            2008-10-13 09:01  2.9K  
 start imp not from system tape.bin 2008-10-13 09:01  2.8K  
 IMP50 Table PS part 1.asc          2008-10-13 09:01  1.9K  
 AP Call Mk7 AL and ABC.bin         2008-10-13 09:01  1.6K  
 README                             2008-10-13 09:01  1.5K  
 PTFC ABCD 5 may.bin                2008-10-13 09:01  1.3K  
 faulty in imp.asc                  2008-10-13 09:02  1.1K  
 bin loader abcd.bin                2008-10-13 09:01  1.0K  
 L new comp bin 2 readers.bin       2008-10-13 09:01  784   
 patch MT to PT.bin                 2008-10-13 09:01  768   
 MT to PT.bin                       2008-10-13 09:01  768   
 load any.bin                       2008-10-13 09:01  672   
 LOAD ANY TO SYSTAPE BIN.bin        2008-10-13 09:01  664   
 list begin.asc                     2008-10-13 09:02   52   
 define RBIM P7WS.asc               2008-10-13 09:01   26   
 define KWK17.asc                   2008-10-13 09:01   26   
 star star t.asc                    2008-10-13 09:01    6