Prospero Software
The PASCAL programming language was developed by Niklaus Wirth
during the early 1970's. It was primarily designed as a teaching
language encouraging the use of structured programming techniques.
Although primarily developed for use in education the language has
been adopted widely in industry and a PASCAL compiler now exists for
almost every make of computer. An international standard for the
Pascal language has been defined by the International Standards
Organisation (ISO), which also developed a suite of validation
programs which are used to demonstrate that the compiler conforms to
the standard.
THE COMPILER
PRO-PASCAL is a full implementation of Pascal
conforming to the requirements of the ISO standard (ISO 7185). The
compiler also includes a number of language extensions. These
include string handling, double precision floating point arithmetic
(IEEE format), random access files and separate compilation
facilities. To assist the writing of portable Pascal programs an
option is available to prohibit the use of these extensions.
The compiler runs from the Desktop as a TOS
application and as such makes little use of GEM facilities.
Compilation speed is quite good. The compiler requires two passes to
compile a source program to produce a link file. During compilation
messages are displayed showing the progress of the compiler through
the source file along with any errors encountered. The messages
produced may be optionally written to a log file. The error messages
produced are quite explicit giving an error number and displaying
the line that is in error. The compiler produces link files in the
widely used GST Linker format. It is possible to link Pascal
routines with routines written in assembly language and PRO-Fortran
77.
The disk supplied includes the Pascal compiler,
the linker, a system configuration program, a librarian program
to enable the creation of custom libraries, a number of linkable
libraries, and a program cross-referencer. Also included is PRL (the
Prospero Run-time Library) in the form of a separate program which
must be executed before the compiler suite will function. This is
identical to the run time system used by Prospero's Pro-Fortran 77
compiler. We share the reservations expressed by Matthew Jones in
his review of Pro-Fortran in issue 22.
THE LIBRARIES
The libraries included with the compiler include
routines giving full access to the GEM AES and VDI, and GEMDOS. The
routines supplied closely resemble the standard C function naming
conventions as described in the GEM documentation. User alterable
bindings to these routines are supplied on the system disk.
Additional routines include memory management, random TEXT files,
program chaining etc...
THE MANUAL
The manual comes in a smart blue ring binder. It
comprises three main sections. The first gives fairly good
introduction to the Pascal language, although a beginner would
probably require a good Pascal teaching guide. The second section
gives a detailed description of the Pro-Pascal implementation of the
Pascal Language. This section includes a guide to the use of the
supplied library functions, including the various GEM calls. The
third section covers the installation and operation of the various
elements of the Pro-Pascal system.
CONCLUSION
Pro-Pascal is a good implementation of the Pascal
language which includes a number of useful routines to enable the
programmer to produce powerful systems making full use of the
facilities made available by the ATARI machines. At £130 the
compiler, though not as cheap as some, is good value for money.
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