this is the scanner/parser/error recovery/code generator part of the 
berkeley pascal system.  code generated by pi is interpreted by px.

before trying to make install, be sure you have the install destination
directory /usr/ucb and the library directory /usr/ucb/lib.
then type `make install'.

other make commands of interest are:
    - `make clean' removes all but the source files for clean recompilations.
    - `make print' prints a copy of everything interesting on standard output.

things that are new in this version:
    - #included files now have date and time stamps in a listing.
    - addresses for transfers are now absolute, rather than relative,
      allowing larger procedures than previously.
    - programs can now have up to 65k of code space.

bugs in the last version that are fixed in this version:
    - a bug causing duplicate tails of redirected listings has been fixed.
    - a bug in the printing of token replacement messages has been fixed.

bugs and limitations introduced in this version:
    - due to limitations of px, each program, procedure or function
      may allocate only 32k bytes of local variables
      (rather than an error-causing 50k in previous version).

differences between the vax and 11 versions:
    - all the things that are new in this version.
    - pointers occupy 4 bytes.  this includes file pointers.
    - the vax version allows up to 65k of code space,
      rather than the 32k of the 11 version.
    - the vax version allows only 32k of data space per procedure/function,
      rather than the 50k of the 11 version.
