Program Status Area - ZiLOG System 8000 User Manual

USER
CHRDEL:
XOFCHR:
XONCHR:
STACK:
PSAREA:
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Zilog
USER
Character Delete (%23F2)
This address stores the character intercepted
by the input line procedure as a character
delete. When it is read from the terminal,
the last character entered is purged from the
input buffer. Multiple character deletes can
be used to delete the last n characters
entered. CHRDEL is initialized to %08
(control-h) •
XOFF Character (%23F5)
The character stored at this address is
interpreted by the input interrupt procedure
as a character that stops outputting data to
the terminal. When it is read from the ter-
minal, all output is suspended until an
XONCHR is received. XOFCHR is initialized to
%13 (control-s).
XON Character (%23F4)
The character stored at this address is
interpreted by the input interrupt procedure
as a character that resumes output after
XOFCHR is entered. When it is read from the
terminal, all output is resumed. XONCHR is
initialized to %11 (control-g).
Stack Pointer (%20AO)
This address is the base of the user stack
set by the Monitor Program at reset. The top
of the stack is %4000.
Program Status Area (%2400)
The Program Status Area for entering various
interrupts and trap handling procedures
starts at this address. This area includes
the program status blocks (FCW and PC) for
different types of interrupts and traps. The
S8000 Monitor Program sets up these program
status blocks as shown in Table 3-1.
Zilog
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