ZCPR33A.DOC - Documentation for ZCPR33A.Z80

ZCPR33A.Z80 is a personalized version of ZCPR33, incorporating my own minor
modification to allow flow control to proceed unmodified throughout the
course of a user-created shell.

As distributed, ZCPR33 does not support flow control during shells, offering
only the two alternatives:

    1)  Allow no flow control at all during shells; flow control commands 
	are simply skipped.

    2)  Allows flow control during shells, but always re-initializes the
	flow control system (popping all IF levels) upon each invocation
	of the shell.

The intent was to prevent the (potentially) unpleasant consequences of 
having a shell which pushes one additional IF level upon each invocation.  
In my opinion, however, the cure is worse than the condition.  I have 
simply disabled some of the code in the command processor.  Custom written 
shells (such as an alias that is installed with the SHSET command) can now 
contain flow commands, and when the shell is finally terminated, the 
system's flow control state will be the same as when the shell was first 
invoked.

I am releasing this file at the specific request of Rick Charnes.  I 
originally made this modification in June or July of 1987, but subsequently 
misplaced or overwrote the source.  I recreated this version only an hour 
ago, and it has been tested only briefly.  My system has been running with 
the modification for a year, to my satisfaction, but there is a possibility 
that this source is slightly different from that I originally used.  If you 
are interested in using it, I recommend you perform your own evaluation of 
its fitness.


Dreas Nielsen
June 11, 1988