Parallaxis is a combination of two programs: a compiler, which
generates PARZ intermediate code, and a simulator, which runs the
intermediate code on whatever machine you have.

Compiler (pa):
==============
Can't mix types in an expression (eg, integers and reals). Must
explicitly cast integer or cardinal to float (eg, float(N)), or
truncate floats to integers (eg, trunc(3.14 * r*r)). Also can use real
constants instead of integer constants, in real expressions.

All variables must be specified as either SCALAR or VECTOR.

If a function is called in a PARALLEL block, it must take VECTOR args
and return a VECTOR value.

Writing a vector variable writes all values of the vector, in order.
Eg, 
  VECTOR x: integer;
  ...
  PARALLEL
   WriteInt(x, 10);
  ENDPARALLEL

id_no is [1..n], if you have n procs, no matter what your
CONFIGURATION statement says. Thus if you say
  CONFIGURATION list[N]
the processes are numbered 0..N-1 for the purpose of the CONNECTION
statement, but id_no runs [1..N] anyway.

Graphics functions are not implemented. 

MAC: The compiler takes its switches through the "Settings..." menu item, 
in a more
mac-like fashion. The compiler is a pain: no scroll bars. Set a limit on
the number of error messages. 

Simulator (pz):
===============
 On Macs the SimulatorFP is for machines with floating point
coprocessor, and can be faster. Seems to crash more though.
 On the DEC you can pass a .p file to the pz simulator and it will
compile it first, then run it.
 On the Mac, launching a .z file runs the simulator on that file.
If you run the Simulator directly, you have access to the pz command
line, and can specify debugging options there. 
To use the debugger:
  Run the simulator and change the command line to 
    simulator -l foo.z
  (that's a little L, not a one). foo.z is the compiled version of your 
program.

  Type 'help' to get a list of commands.

Read the man pages for other simulator switches.

MAC: It appears that if you don't change the simulator command line, a 
file dialog comes
up, but there will be no dialog box if you change the command line. Thus 
the file name must be given there. In that case, it seems the file must 
be in the same folder.

Timing (ptiming):
=================
To measure times, get a trace of the program run (here the memory etc
on the Mac may really limit you) in a file. eg,
   pz -r1myprog.out myprog.z
This will do a mode '1' recording to file 'myprog.out'. Then run the
program called 'ptiming'. Supply it the name myprog.out, and tell it
where you want the statistics output (RETURN is a good choice). Enter
0 at the next question to get stats only. Then hit return twice,
choosing the default which says that a propagate or reduce costs 10
times as much as a regular instruction.