P2P.DMP










	by R.Helliwell








               P2P  is a program for reading, punching,
          and  comparing  paper  tapes.   As  an  added
          feature  it  will  take  any tape that can be
          loaded with the 20 loader and punch a  readin
          mode  20 loader at the beginning of it.  This
          allows you to use the readin  switch  on  the
          PDP-10  (the  one on the PDP-6 doesn't do the
          same thing).   Also  it  will  punch  a  test
          pattern  so  that you may see if the punch is
          dropping any bits.

P2P.DMP						    SAILON NO. @@


     The following is a table of commands for P2P.  You must type
the  full  command  word  or  the  first  letter followed by <cr>
(except you must always type RIM20, R means READ).

COMMAND			MEANING


CLEAR          This zeroes the P2P buffer area (it allows you  to
               punch a rim 20 loader by itself).
                  

READ           This reads a  tape  into  the  buffer  area.   The
               program will respond with:
                  
               	LOAD TAPE AND RETURN
                  

COMPARE        This reads a tape and compares it with the one  in
               the  buffer.   If the tape compares ok the program
               responds with "TAPE OK".
                  

PUNCH          This punches what is in the buffer.
                  

TEST           This punches the word "TEST" on the tape  followed
               by some worst case bit patterns.
                  

RIM20          This punches what is in the buffer preceeded by  a
               read  in  mode 20 loader.  When using the tape the
               20 loader starts itself and reads in the  rest  of
               the  tape  as  if  you  had  started the 20 loader
               already in core.

P2P.DMP						    SAILON NO. @@

The following is a list of error messages and their meanings.

MESSAGE			MEANING


PTR BUSY       Someone else is using the paper tape reader.
                  

PTP BUSY       Someone else is using the paper tape punch.
                  

CORE EXCEEDED, RETURN TO TRY AGAIN.
                  

               This means that the program needed more  core  and
               lost trying to get it.
                  

INPUT ERROR    There was an input error.All I-O is terminated and
               you are left in command mode.
                  

OUTPUT ERROR   There was an output error.  All I-O is  terminated
               and you are left in command mode.
                  

The following occur if the compare routine finds a mistake.
                  

SHORT TAPE      This  means  the  input  tape  ended  before  the
               information in the buffer did.
                  

EXTRA DATA ON END OF TAPE
                  

               This means that there was more data  on  the  tape
               than in the buffer.
                  

COMPARE ERROR    

TAPE   0 0 0 0 0 . 0 0 1

MEMORY 0 0 0 0 0 . 0 0 0
                  
               This   would  indicate  that  the  tape  you  were
               comparing had an extra hole punched in column 1.