Software Review by R.O’ FARRELL
Entec = esses
INTEGER PASCAL: Initial impressions.
From: Datron, 2 Abbeydale Road, Sheffield
Cost 35.00 plus VAT
This compiler may well be many microcomputer users introduction to the Pascal
It comes in a number of versions which are specific to the monitor you use. My copy
was designed to run with Nas-Sys 1, and in consequence there may be minor differences
in the monitor dependant routines – e.g. the Nas-Sys on screen edit, which is not
available under the other monitors.
The program is supplied on a tape, recorded in my case at 300 Baud CUTS, using the
Block routines rather than the Tabulate format. It is designed to load at 1000H, and
takes some considerable time to load, occupying memory up to approx 3200H. It contains
within it a text editor to allow you to build up the program which you wish to
compile. This test editor is idiosyncratic (that is, it’s not like any text editors I
know), and takes getting used to. It allows a program to be built up, a line
displayed, or deleted. It also automatically renumbers the lines of the program when
instructed, and has the ability to output a program listing to the VDU or to a
printer. It can also save a program on tape, and read it back in. Each line must have
a number, but the number does not necessarily put the line in its correct position in
the buffer – this is done by a location pointer. Any corrections have to be made by
either retyping the line, or by using the Nas Sys on screen edit.
The editor needs each action to be preceeded with a command letter, and the location
of the line pointer decides where the line you have just typed/replaced/deleted is (or
was). The editor works fairly well, but I feel that more work could be done on it, to
bring it more towards the way a Basic interpreter builds up a program, which I think
would be more familiar to most users.
Having entered the program, the Pascal compiler having been started by the following
E1000 BUFFERSTART BUFFERLENGTH
then you can try a compilation. This you do by using the "C" command. When entered on
its own with no ancillary parameter, this command causes a trial compilation to take
place. As the program compiles, it scrolls up on the screen the lines of the program.
Should an error be found, the compilation is aborted, and one of 28 hex values is
displayed with an error message. Reference to the manual is necessary to find out what
the hex value indicates to be wrong. If the compilation is successful, then you can
enter the "C" command again, this time followed by a Hex address, and the Z80 code
will be generated there. You can now either leave the compiler, and jump to the code
with the monitor E command, or you can use the compiler "G" command to execute the
program and return to the compiler when finished.
The compiler occupies Memory 1000H – 3200H, and uses 3200H – 3750H as workspace.
Memory outside this can be used for the source buffer, which is defined on entry to
the compiler by additional parameters for start and length. If these parameters are
omitted on first entry to the compiler, an error message is printed, and you are put
back in the monitor.
As can be seen from the above figures, a 32K system would be desirable, particularly
if you wish to write a long program in Pascal.