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OTHER SYSTEM FUNCTIONS
EXIT CONDITIONS:
27.5 -- Other Functions
This
~unction
does
not
return
to the
call ing pl'ogram.
A new copy
01=
MDOS
is
brought
from
the
diskette into
memory.
All
of
the
functions
perfol'med
during
this
type
-of
initialization
are
de$c~ibed
in
sec ticn
2. 1
and
sec ti on
24. 6.
Control is given to the MDOS
command
interpreter
after
MOOS
has
been
initial i zed.
27.5.4 Set system error status word -- . EWORD
The . EWORD function configures the system
error
status
word
with
a
specific
er~or
type.
This allows
a
calling
program
to
indicate
that
an
error
occurred
during
its
execution.
The
system error status word can then be tested
from within a CHAIN procedure (Chapter 6).
ENTRY PARAMETERS:
EXIT CONDITIONS:
B
=
The value that is to be
placed
into
the
Error
Type
field of the system
error
status
word.
Any
value
is
valid.
Section
28.4
describes the
format of the error status word.
A is unchanged.
B is' unchanged.
X is unchanged.
CC is indeterminate.
The
lowe~
byte of the system
e~ror
status
~ord
contains the value passed in B.
The
Er~or
Status Flag has
also
been
set
to
one.
Th e
rema
i
nde~
of th e
error status
~ord
is unchanged.
27.5.5 Allocate user program memory -- . ALUSM
The .ALUSM Function adjusts the MDOS pointer
ENDUS$
to
reflect
the
end
of
the
user
prog~am
area.
This function
facilitates the
~ynamic
allocation of variable
buffer
space
adJacent
to
the
highest
loaded
prog~am
location so that
programs
can
take
advantage
of
the
variable
amount
of
contiguous.
memory
that
may
be
configured
for
a
given
installation.
The user program area consists of all contiguous
memory
between
the end of the resident operating system and the end
of contiguous memory.
The pointer
ENDUS$
is
automatically
PaQe
27-40
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