PASCAL - OS/8, Version: V1-0-F, February 1984

Author: John T. Easton, University of Minnesota, Minneapolis, MN

Operating System: OS/8 V3 Source Language: PASCAL, PDP-8
MACREL-LINK Memory Required: 24KW Keywords: Language In-
terpreters; PASCAL; Programming Languages; Structured Languages/
Programming; Tools - Application Development; Tools - Software

Abstract: PASCAL - OS/8 is a software system that implements the
programming language PASCAL for the PDP-8 family of minicomputers
running the OS/8 operating system. PASCAL-OS/8 consists of a compiler
(written in PASCAL), a run-time-system with interpreter, and numerous
utility programs and example programs written in PASCAL. Documen-
tation is in printed form, about 135 pages long. PASCAL-OS/8 adheres to
the ISO standard for PASCAL. It installs very simply. The implementation
represents several years of work. It has been run on both PDP-8E and
PDP-12. It is implemented with no PDP-8E dependencies.

Major limitations are: identifiers are distinguished on only the first
eight characters; 24K memory is needed to compile; there is no library
mechanism or assembly language linking mechanism.

Features include: up to 32K memory is utiliized; Post-Mortem-
Display (PMD), execution error traceback is automatic; large programs
may be segmented to fit available memory; several internal device
handlers allow flexible interactive Input/Output; an FPP is used if present
but is not required; it is compatible with two-page system handlers; it can
run well under OS/8 BATCH.

Extensions include: flexible facilities for accessing OS/8 files,
including direct (random or indexed) access files; three-way packed OS/8
character files may be accessed as type TEXT, file of ASCII, or file of
EightBit; Date routine; Execute(string) calls CCL; Halt(message) aborts
execution; otherwise in case statement; others.

Performance is greatly enhanced if the OS/8 system has a fast disk
such as an RK05, and/or if a full 32k memory is available. Performance is
roughly similar to OS/8 BASIC. Installation consists of copyinng some files
to SYS:. Test sites report that PASCAL-OS/8 is complete, easy to install,
and easy to use.

Note: The complete sources for PASCAL-OS/8 currently require a lot of
disk space: RK05 disk for the run-time system sources and supporting
PASCAL tools; RK05 for the compiler sources and supporting PASCAL
tools; RK05 for the documentation source files.

Documentation available in hard copy only.

Media Service Charge Code: Manual (EC), DECtape (HB), Floppy
Diskette (KB)
Format: OS/8
Catalog: June 1985