[~-
[
Assemble
Purpose:
r Assembles
8086/8087/8088
mnemonics directly into memory.
[~
Syntax:
A[address]
Comments:
If
a syntax
error
is
found,
debug
responds with
the
following
message,
then
redisplays
the
current
assembly address:
IIError
All
numeric values are hexadecimal and
you
must type
them
as
1-4
characters.
Also,
you must specify prefix mnemonics
in
front
of
the
opcode
to
which
they refer. You may type
them
on
a
separate line, however.
The segment override mnemonics are
CS:,
OS:,
ES:,
and
SS:.
The
mnemonic for
the
far return is RETF. String manipulation
mnemonics must explicitly state
the
string size. For example, use
MOVSW
to move
word
strings, and use
MOVSB
to move
byte
strings.
The
assembler will automatically assemble short, near,
or
far
jumps and calls, depending
on
byte displacement,
to
the
destina-
tion address. You may override these jumps and calls
by
using a
NEAR
or
FAR
prefIX,
as in
the
following example:
0100:0500
JMP
0100:0502
JMP
0100:505
JMP
502
NEAR
505
FAR
50A
a
2-byte
short
jump
a
3-byte
near
jump
a
5-byte
far
jump
You may abbreviate
the
NEAR prefix
to
NE,
but
the
FAR prefix
cannot
be
abbreviated.
Debug
cannot tell
whether
some operands refer to a
word
memory location
or
to a
byte
memory location. In this case,
the
data type must
be
explicitly stated with
the
prefix, WORD PTR
or
BYTE
PTR. Acceptable abbreviations are WO and
BY.
For
example:
NEG
DEC
BYTE
PTR
[128]
WO
[5
I ]
Debug
2131
(A)ssemble
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