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OTHER SYSTEM FUNCTIONS
27.5 -- Other Functions
The
user
SWI
and
IRQ
vectors main'tained
by MDOS (SWI$UV and IRG$UV)
are
reset
to
point to an
RTI
instruction.
The
user program is no
longer
resident,
thus
user-defined
SWI
and
IRG
interrupts cannot be processed
after
MDOS regains centrel.
The
end
oT
user memOTY pointer, END$US,
is reset.
The command line buffer is initialized.
The version/revision numbers of
MDOS
in
memor~
are
compared
with
the
version/revision numbers
in
the
1D
sector.
The addresses of the system
overlays are also
compared
in
this
~ashion.
If
a
discrepancy
exists
between
memory
and
the
diskette,
EXbug is given control.
The
system
IOCBs
for
the
printer, and the
MDOS
error
rile are configured.'
console,
message
The
input
prompt
(=)
is displayed and a
new command line
accepted
from
the
system console.
The
system
error status word is cleared
(Error Type and Error Status Flag)
if
a valid command is interpreted.
27.5.3 Reload MOOS from diskette -- . BOOT
The . BOOT function reloads the resident operating system
from the diskette in drive
ze~o
via the
diskette
controller
firmware.
This
function' should
be
used
if the resident
operating
s~stem
has been changed
by
the current
prog~am
(SWI
handler
must still be intact).
This function should also be
used if the diskette in drive zero
has
been
replaced
with
another
MDOS
diskette
since
the
last
time
MDOS
~as
initialized via the debug monitor . . BOOT is one of
the
few
functions
that
does
not
return
control
to
the
calling
program.
This function has the same effect as
if
the
ABORT
or
RESTART
pushbuttons
were depressed on the EXORciser and the
debug command "E800i
Gil
or
"MDOS"
executed.
ENTRY
PARAMETERS:
A valid MDOS diskette must
be
ready
in
drive zero.
Page
27-39
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