Introduction; Scope; Features Of The Ge/Pac 4020 Computer - GE PAC 4020 System Manual

INTRODUCTION
SCOPE
This manual presents the specifications, internal
organization, operation and machine-level pro-
gramming characteristics of the GE/PAC 4020*
central processor, bulk memories, peripheral de-
vices, remotes and subsystems. ·
The machine- level programming information is
included to help explain how the equipment works,
not how it should be programmed. Virtually all the
real-time and input-output functions required for
process monitoring and control are implemented by
calling sequences to the GE/PAC 4020 computer's
Real-Time Operating System (RTOS), which differ
from the machine-level formats in both scope and
detail. This manual will refer to RTOS occasionally,
in those situations in which RTOS software substan-
tially enhances or adds to the features wired into the
equipment.
For information on how to program the GE/PAC
4020 computer, please refer to the GE/ PAC 4020
Programming Manual and to the detailed reference
manuals on the languages (FORTRAN, PAL, TASC),
operating systems and other useful programs.
FEATURES OF THE GE/PAC 4020 COMPUTER
Thanks to its monolithic integrated circuits and
to its heritage from the GE 412 and the earlier
members of the compatible GE/PAC 4000 process
computer family, the GE/PAC 4020 computer com-
bines high performance, high reliability, ease of
programming and compactness. Its large command
repertoire, long word, extensive input-output
buffering, realistic process interface arrangements,
and excellent safety characteristics offer unparal-
leled value for a wide variety of real-time appli-
cations. These features are aimed at reducing total
project cost, not at reducing cost in one area at the
expense of another.
The monolithic integrated circuits used in the
GE/PAC 4020 computer reduce the number of active
components, connections and wiring by a factor of
five, improving system reliability. These circuits
also greatly reduce the physical area required for a
given function, improving noise rejection charac-
teristics and permitting safe and solid operation at
clock frequencies higher than those usable with con-
ventional or hybrid circuits.
Accompanying the GE/PAC 4020 central proc-
essor is a full line of bulk memories, peripheral
devices, process-oriented subsystems, and devices
for remote communication and control, encompassing
many application requirements.
*Registered Trademark , General Electric Co.
Related General Electric products include
GE/MAC electronic process instrumentation,
GE/TAC remote telemetering and supervisory con-
trol, GE X-Ray Emission Gages (XEG's) and other
special sensors, Directo-Matic II wired-program
analog and digital control equipment, GE 400 and
600-series scientific and data processing computer
systems, GE datasets and microwave, GE Mark
Century numerical control and the full line of GE
electrical apparatus.
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