CONSOLE-CONTROL PROCEDURES FOR PASCAL/Z

	The console-control procedures "Conact", GotoXY", 
and "ReadXY" are provided as built-in extensions to the 
language in Pascal/M and UCSD Pascal, but not in Pascal/Z. 
The accompanying files "CONACT.PSP" and "GOTOXY.PSP" 
(filetype "PSP" is for "PaScal Procedure", to distinguish 
such a file from an executable Pascal program) provide two 
of these procedures. The third, "ReadXY", has not yet been 
successfully implemented, for reasons described later.
	Since the Pascal/M and UCSD console procedures are 
called frequently from programs written in either of these 
two implementations of Pascal, conversion of such programs 
to Pascal/Z can be done much more easily if the necessary 
procedures can simply be included in the program and called
in the same way. Since most CRT terminals use different 
control codes for the actions needed, however, it will be 
necessary to change the codes shown here to whatever your 
own terminal requires. In most cases, this will require no 
changes in the procedure headings or the formal parameter 
types, though, so the interface to the programs can be the 
same, no matter which terminal you have. To repeat a theme 
I've used elsewhere, maximum compatibility between 
different programmers, and different dialects of Pascal, 
should benefit all of us -- and if you take the trouble to 
get these procedures working right for your hardware setup,
and then use them in your own programs, it should be one 
more step toward this goal.
	Since it may not always be obvious, from the 
information given in the various manuals (it certainly 
wasn't in mine), exactly how to get hardware-dependent 
procedures like these working right, some trial and error 
may be required. To facilitate this process, I also wrote 
a program called "CONSOLE.PAS", to test the procedures.
Unfortunately, neither this nor "READXY" could be included 
on this disk, due to two problems with Pascal/Z that I 
haven't yet figured out solutions for. One is that the 
"Read" function is improperly implemented from the "Input" 
(console) file, and it acts like "Readln" instead (waits 
for a "Return" before accepting the input). The other is 
the failure to provide a non-echoing mode for inputs from 
the console, like the "Keyboard" file in Pascal/M and UCSD.
Together these flaws make it impossible to move the cursor 
around under user control, or accept the X,Y return values 
from "ReadXY", since everything keeps getting echoed to the
screen. I've tried a number of ways of working around these
problems, including the "Input" procedure on p. 77 of the
Pascal/Z Manual, but so far without success. If I were a 
better assembly-language programmer, I might have been able
to make it work, but (now, here comes the soapbox) the 
whole point of using a high-level (and in the case of 
Pascal/Z, high-priced!) language is to avoid having to do 
this sort of low-level hacking. After about a week of 
unsuccessful attempts, I decided that there were better 
ways to spend my time than trying to add features to the 
language that should have been there in the first place. 
Good console-control procedures are a must for a language 
that's going to be used to develop serious applications 
software, and I can only hope that they are provided for 
Pascal/Z before much longer (sorry about the tirade, but it
was a long, frustrating experience). Anyway, try out the 
two procedures that I was able to use (they seem to work in
my programs, at least -- see "ARTIL/Z.PAS" for some 
examples), and good luck with them.

			Jim Bearden
			Cancer Center, University of Hawaii
			1236 Lauhala Street
			Honolulu, Hawaii 96813

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