<s>
The	O
Microsoft	B-Application
Macro	I-Application
Assembler	I-Application
(	O
MASM	B-Application
)	O
is	O
an	O
x86	B-Operating_System
assembler	B-Language
that	O
uses	O
the	O
Intel	B-Language
syntax	I-Language
for	O
MS-DOS	B-Application
and	O
Microsoft	B-Application
Windows	I-Application
.	O
</s>
<s>
Beginning	O
with	O
MASM	B-Application
8.0	O
,	O
there	O
are	O
two	O
versions	O
of	O
the	O
assembler	B-Language
:	O
One	O
for	O
16-bit	B-Device
&	O
32-bit	O
assembly	O
sources	O
,	O
and	O
another	O
(	O
ML64	B-Application
)	O
for	O
64-bit	B-Device
sources	O
only	O
.	O
</s>
<s>
MASM	B-Application
is	O
maintained	O
by	O
Microsoft	O
,	O
but	O
since	O
version	O
6.12	O
it	O
has	O
not	O
been	O
sold	O
as	O
a	O
separate	O
product	O
.	O
</s>
<s>
It	O
is	O
instead	O
supplied	O
with	O
various	O
Microsoft	O
SDKs	B-Application
and	O
C	B-Language
compilers	O
.	O
</s>
<s>
Recent	O
versions	O
of	O
MASM	B-Application
are	O
included	O
with	O
Microsoft	B-Application
Visual	I-Application
Studio	I-Application
.	O
</s>
<s>
Notable	O
applications	O
written	O
in	O
MASM	B-Application
are	O
RollerCoaster	B-Application
Tycoon	I-Application
which	O
was	O
99%	O
written	O
in	O
MASM	B-Application
.	O
</s>
<s>
The	O
earliest	O
versions	O
of	O
MASM	B-Application
date	O
back	O
to	O
1981	O
.	O
</s>
<s>
They	O
were	O
sold	O
either	O
as	O
the	O
generic	O
"	O
Microsoft	B-Application
Macro	I-Application
Assembler	I-Application
"	O
for	O
all	O
x86	B-Operating_System
machines	O
or	O
as	O
the	O
OEM	O
version	O
specifically	O
for	O
IBM	B-Device
PCs	I-Device
.	O
</s>
<s>
Up	O
to	O
Version	O
3.0	O
,	O
MASM	B-Application
was	O
also	O
bundled	O
with	O
a	O
smaller	O
companion	O
assembler	B-Language
,	O
ASM.EXE	O
.	O
</s>
<s>
This	O
was	O
intended	O
for	O
PCs	O
with	O
only	O
64k	O
of	O
memory	O
and	O
lacked	O
some	O
features	O
of	O
the	O
full	O
MASM	B-Application
,	O
such	O
as	O
the	O
ability	O
to	O
use	O
code	O
macros	O
.	O
</s>
<s>
MS-DOS	B-Application
versions	O
up	O
to	O
4.x	O
included	O
Microsoft	O
's	O
LINK	O
utility	O
,	O
which	O
was	O
designed	O
to	O
convert	O
intermediate	O
OBJ	B-Application
files	I-Application
generated	O
by	O
MASM	B-Application
and	O
other	O
compilers	O
;	O
however	O
,	O
as	O
users	O
who	O
did	O
not	O
program	O
had	O
no	O
use	O
of	O
the	O
utility	O
,	O
it	O
was	O
moved	O
to	O
their	O
compiler	O
packages	O
.	O
</s>
<s>
Through	O
version	O
5.0	O
,	O
MASM	B-Application
was	O
available	O
as	O
an	O
MS-DOS	B-Application
application	O
only	O
.	O
</s>
<s>
Versions	O
5.1	O
and	O
6.0	O
were	O
available	O
as	O
both	O
MS-DOS	B-Application
and	O
OS/2	B-Application
applications	O
.	O
</s>
<s>
By	O
the	O
end	O
of	O
the	O
year	O
,	O
version	O
6.1A	O
updated	O
the	O
memory	O
management	O
to	O
be	O
compatible	O
with	O
code	O
produced	O
by	O
Visual	B-Application
C++	I-Application
.	O
</s>
<s>
In	O
1993	O
full	O
support	O
for	O
protected	O
mode	O
32-bit	O
applications	O
and	O
the	O
Pentium	B-General_Concept
instruction	O
set	O
was	O
added	O
.	O
</s>
<s>
The	O
MASM	B-Application
binary	O
at	O
that	O
time	O
was	O
shipped	O
as	O
a	O
"	O
bi-modal	O
"	O
DOS-extended	O
binary	O
(	O
using	O
the	O
Phar	O
Lap	O
TNT	O
DOS	O
extender	O
)	O
.	O
</s>
<s>
Version	O
6.11	O
is	O
the	O
last	O
version	O
of	O
MASM	B-Application
that	O
will	O
run	O
under	O
MS-DOS	B-Application
.	O
</s>
<s>
By	O
the	O
end	O
of	O
1997	O
,	O
MASM	B-Application
fully	O
supported	O
Windows	B-Application
95	I-Application
and	O
included	O
some	O
AMD-specific	O
instructions	O
.	O
</s>
<s>
In	O
1999	O
,	O
Intel	O
released	O
macros	O
for	O
SIMD	B-Device
and	O
MMX	B-Architecture
instructions	O
,	O
which	O
were	O
shortly	O
thereafter	O
supported	O
natively	O
by	O
MASM	B-Application
.	O
</s>
<s>
With	O
the	O
6.15	O
release	O
in	O
2000	O
,	O
Microsoft	O
discontinued	O
support	O
for	O
MASM	B-Application
as	O
a	O
separate	O
product	O
,	O
instead	O
subsuming	O
it	O
into	O
the	O
Visual	B-Application
Studio	I-Application
toolset	O
.	O
</s>
<s>
Though	O
it	O
was	O
still	O
compatible	O
with	O
Windows	B-Device
98	I-Device
,	O
current	O
versions	O
of	O
Visual	B-Application
Studio	I-Application
were	O
not	O
.	O
</s>
<s>
Support	O
for	O
64-bit	B-Device
processors	I-Device
was	O
not	O
added	O
until	O
the	O
release	O
of	O
Visual	B-Application
Studio	I-Application
2005	O
,	O
with	O
MASM	B-Application
8.0	O
.	O
</s>
<s>
After	O
25	O
June	O
2015	O
,	O
there	O
are	O
at	O
least	O
three	O
different	O
MASMs	B-Application
with	O
the	O
version	O
number	O
14.00.23026	O
.	O
</s>
<s>
In	O
Microsoft	B-Application
Visual	I-Application
Studio	I-Application
2015	O
Enterprise	O
Edition	O
,	O
there	O
is	O
one	O
"	O
amd64_x86	O
"	O
ml	O
and	O
two	O
ml64s	B-Application
,	O
"	O
x86_amd64	O
"	O
and	O
"	O
amd64	O
"	O
.	O
</s>
<s>
Early	O
versions	O
of	O
MASM	B-Application
generated	O
object	B-Application
modules	I-Application
using	O
the	O
OMF	O
format	O
,	O
which	O
was	O
used	O
to	O
create	O
binaries	O
for	O
MS-DOS	B-Application
or	O
OS/2	B-Application
.	O
</s>
<s>
Since	O
version	O
6.1	O
,	O
MASM	B-Application
is	O
able	O
to	O
produce	O
object	B-Application
modules	I-Application
in	O
the	O
Portable	O
Executable	O
(	O
PE/COFF	O
)	O
format	O
.	O
</s>
<s>
PE/COFF	O
is	O
compatible	O
with	O
recent	O
Microsoft	O
C	B-Language
compilers	O
,	O
and	O
object	B-Application
modules	I-Application
produced	O
by	O
either	O
MASM	B-Application
or	O
the	O
C	B-Language
compiler	O
can	O
be	O
routinely	O
intermixed	O
and	O
linked	O
into	O
Win32	O
and	O
Win64	O
binaries	O
.	O
</s>
<s>
Some	O
other	O
assemblers	B-Language
can	O
assemble	O
most	O
code	O
written	O
for	O
MASM	B-Application
,	O
with	O
the	O
exception	O
of	O
more	O
complex	O
macros	O
.	O
</s>
<s>
Turbo	B-Application
Assembler	I-Application
(	O
TASM	B-Application
)	O
developed	O
by	O
Borland	O
,	O
later	O
owned	O
by	O
Embarcadero	O
,	O
last	O
updated	O
in	O
2002	O
,	O
but	O
still	O
supplied	O
with	O
C++Builder	B-Language
and	O
.	O
</s>
<s>
JWasm	B-Application
Macro	O
Assembler	B-Language
,	O
licensed	O
under	O
the	O
Sybase	O
Open	O
Watcom	O
EULA	O
.	O
</s>
<s>
Pelle	O
's	O
Macro	O
Assembler	B-Language
,	O
a	O
component	O
of	O
the	O
development	O
environment	O
.	O
</s>
<s>
is	O
a	O
free	O
MASM-compatible	O
assembler	B-Language
based	O
on	O
JWasm	B-Application
.	O
</s>
<s>
is	O
a	O
free	O
MASM-compatible	O
assembler	B-Language
based	O
on	O
JWasm	B-Application
.	O
</s>
<s>
Documentation	O
for	O
1987	O
's	O
version	O
5.1	O
included	O
support	O
for	O
"	O
Microsoft	O
BASIC	O
,	O
C	B-Language
,	O
FORTRAN	O
,	O
Pascal.	O
"	O
</s>
