Excerpted from "RT-11 Product Description"
RT-11 is a single-user, realtime operating system de-
signed to operate on the PDP-11 series of processors.
Small, fast and efficient, it has been used as the base for
many applications in a variety business, commercial
and scientific environments. Capable of both realtime and
data processing, RT-11 also offers a full range of system
utilities to facilitate interactive program development.
The straight forward design of RT-11 contributes to its
inherent ease-of-use and efficient utilization of system
resources. The operating system itself requires minimal
system overhead, optimizing the available user space for
storing programs and data.
The RT-11 Operating System offers the following run-time
environments:
Foreground/Background (FB) Monitor - Provides for the
simultaneous execution of up to 7 jobs in the foreground
and a background job. The real-time function is accom-
plished in the foreground, which has priority on system
resources. Functions that donot have critical response
time requirements, such as program development, are
accomplished in the background, which operates when
ever jobs in the foreground are not running. Within
their priorities, both the jobs in foreground and the
background job are fully functional RT-11 programs with
access to system capabilities.
Single Background (SB) Monitor - Is a single job version
of the Foreground/Background (FB) Monitor.
Extended Memory (XM) Monitor - Has the features of the
FB monitor and supports systems with more than 64K
bytes of memory. XM allows programs to extend their
size to the full PDP-11 virtual address space of 64K
bytes. By program control an RT-11 job may allocate and
use all available physical memory not used by the monitor
or other jobs. A linker option allows user programs to
have overlays in extended memory for fast access.
Extended Background (XB) Monitor - Is a single job version
of the Extended Memory (XM) Monitor.
Supervisor and I-D (ZM) Monitor - Has the features of the
XM monitor and supports systems with more than 64K
bytes of memory. ZM allows programs to extend their
size to the full PDP-11 virtual address space of 64K bytes
and has additonal programmed requests that allow you to extend
a programs logical addressing space into User and Supervisor
modes and in seperated Instruction and Data spaces.
By program control an RT-11 job may allocate and
use all available physical memory not used by the monitor
or other jobs. The linker supports seperate I-D space and
allows user programs to have overlays in extended memory
for fast access.
Single Supervisor and I-D (ZB) Monitor - Is a single job
version of the Supervisor and I-D (ZM) Monitor.
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