ZiLOG System 8000 User Manual page 58
Zeus operating system manual
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Also See for System 8000:
- Hardware reference manual (366 pages) ,
- Hardware reference manual (100 pages)
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USER
48
Zilog
USER
privileged instruction
program
An instruction
intended
for
use
pri-
marily by an operating system, which can
be executed only
in
system
mode.
In
general,
instructions
that
change the
processor
state
or
perform
I/O
are
privileged.
A program (usually synonymous with
~
mana)
is
a binary file that performs a
useful function.
Program Counter (PC)
One of the two Program Status registers.
Contains
the
address
of
the
current
instruction word.
Program Status Area
The area
in
memory
reserved
for
the
starting program status of the interrupt
and trap service routines.
Program Status Area Pointer
The register that contains the
starting
address of the Program Status Area.
Program Status registers
prompt
pwd
register
The two registers (PC and FCW) that con-
tain the program status.
Many programs print a prompt on the ter-
minal when they expect input.
For exam-
ple, the shell prompts for input with
a
percent sign
(%).
The lllid command
prints
the
full
path
name of the current working directory.
A storage
location
in
hardware
logic
other
than
the
memory.
Bits within a
register are numbered from 0,
with
the
least
significant
being the rightmost.
(See also byte register, word
register,
register pair, and register quad.)
Zilog
48
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