<s>
The	O
Atari	B-Language
Microsoft	I-Language
BASIC	I-Language
and	O
Atari	B-Language
Microsoft	I-Language
BASIC	I-Language
II	I-Language
variants	O
of	O
the	O
6502-version	O
of	O
Microsoft	B-Language
BASIC	I-Language
ported	O
to	O
the	O
Atari	B-Device
8-bit	I-Device
machines	O
.	O
</s>
<s>
The	O
first	O
version	O
,	O
released	O
1981	O
,	O
required	O
32KB	O
of	O
RAM	B-Architecture
and	O
was	O
supplied	O
on	O
floppy	B-Device
disk	I-Device
.	O
</s>
<s>
The	O
second	O
version	O
,	O
released	O
the	O
next	O
year	O
,	O
had	O
most	O
of	O
the	O
code	O
on	O
a	O
ROM	B-Protocol
cartridge	I-Protocol
with	O
additional	O
functions	O
on	O
an	O
optional	O
floppy	B-Device
.	O
</s>
<s>
Atari	B-Language
Microsoft	I-Language
BASIC	I-Language
was	O
highly	O
compatible	O
with	O
contemporary	O
BASICs	O
like	O
AppleSoft	B-Language
BASIC	I-Language
and	O
Commodore	B-Language
BASIC	I-Language
,	O
in	O
contrast	O
to	O
their	O
own	O
Atari	B-Language
BASIC	I-Language
which	O
was	O
a	O
somewhat	O
different	O
dialect	O
and	O
incompatible	O
in	O
many	O
ways	O
.	O
</s>
<s>
Like	O
Atari	B-Language
BASIC	I-Language
,	O
Atari	B-Language
Microsoft	I-Language
BASIC	I-Language
included	O
a	O
number	O
of	O
new	O
commands	O
and	O
features	O
to	O
take	O
advantage	O
of	O
the	O
Atari	O
platform	O
.	O
</s>
<s>
These	O
were	O
only	O
partially	O
compatible	O
with	O
the	O
similar	O
features	O
of	O
Atari	B-Language
BASIC	I-Language
.	O
</s>
<s>
When	O
Microsoft	O
ported	O
their	O
originally	O
Intel	O
8080-based	O
BASIC	O
to	O
the	O
6502	B-General_Concept
,	O
they	O
took	O
the	O
time	O
to	O
expand	O
the	O
floating-point	B-Algorithm
format	I-Algorithm
from	O
the	O
original	O
32-bit	O
format	O
to	O
an	O
optional	O
40-bit	O
format	O
for	O
improved	O
accuracy	O
.	O
</s>
<s>
The	O
Atari	B-Device
8-bit	I-Device
home	O
computers	O
were	O
designed	O
with	O
a	O
slot	O
for	O
an	O
8KB	O
ROM	B-Protocol
cartridge	I-Protocol
.	O
</s>
<s>
Atari	O
's	O
programmers	O
struggled	O
to	O
fit	O
Microsoft	O
's	O
BASIC	O
into	O
a	O
single	O
cartridge	B-Protocol
while	O
also	O
adding	O
features	O
to	O
take	O
advantage	O
of	O
the	O
platform	O
.	O
</s>
<s>
In	O
the	O
summer	O
of	O
1978	O
,	O
Atari	O
decided	O
to	O
outsource	O
the	O
porting	O
effort	O
so	O
that	O
BASIC	O
would	O
be	O
ready	O
in	O
time	O
for	O
the	O
1979	O
launch	O
of	O
the	O
system	O
,	O
and	O
this	O
led	O
them	O
to	O
Shepardson	B-Device
Microsystems	I-Device
Inc	O
.	O
(	O
SMI	O
)	O
.	O
</s>
<s>
This	O
became	O
Atari	B-Language
BASIC	I-Language
and	O
was	O
released	O
with	O
the	O
Atari	O
400	O
and	O
800	O
in	O
1979	O
.	O
</s>
<s>
Atari	O
continued	O
working	O
with	O
the	O
MS	O
code	O
and	O
released	O
a	O
version	O
of	O
it	O
on	O
floppy	B-Device
disk	I-Device
in	O
1981	O
.	O
</s>
<s>
In	O
addition	O
to	O
the	O
extended	O
range	O
of	O
standard	O
commands	O
in	O
MS	O
compared	O
to	O
Atari	B-Language
BASIC	I-Language
,	O
the	O
new	O
version	O
added	O
a	O
number	O
of	O
additional	O
commands	O
for	O
graphics	O
and	O
sound	O
and	O
other	O
features	O
of	O
the	O
platform	O
.	O
</s>
<s>
However	O
,	O
as	O
it	O
required	O
at	O
least	O
32KB	O
of	O
RAM	B-Architecture
and	O
only	O
ran	O
from	O
a	O
disk	O
,	O
it	O
was	O
never	O
particularly	O
popular	O
.	O
</s>
<s>
A	O
second	O
release	O
,	O
Atari	B-Language
Microsoft	I-Language
BASIC	I-Language
II	I-Language
,	O
moved	O
most	O
of	O
the	O
code	O
onto	O
an	O
expanded	O
16KB	O
cartridge	B-Protocol
and	O
placed	O
an	O
additional	O
11KB	O
of	O
more	O
rarely	O
used	O
code	O
on	O
disk	O
,	O
meaning	O
that	O
many	O
programs	O
intended	O
for	O
cross-platform	O
use	O
could	O
now	O
be	O
run	O
from	O
the	O
cartridge	B-Protocol
alone	O
.	O
</s>
<s>
The	O
underlying	O
interpreter	O
was	O
based	O
on	O
the	O
same	O
9KB	O
MOS	B-General_Concept
6502	I-General_Concept
code	O
that	O
also	O
formed	O
the	O
basis	O
of	O
Commodore	B-Language
BASIC	I-Language
and	O
AppleSoft	B-Language
BASIC	I-Language
,	O
and	O
was	O
largely	O
compatible	O
with	O
them	O
.	O
</s>
<s>
In	O
contrast	O
,	O
Atari	B-Language
BASIC	I-Language
used	O
an	O
entirely	O
different	O
system	O
that	O
treated	O
strings	O
as	O
arrays	O
of	O
characters	O
and	O
was	O
not	O
compatible	O
with	O
,	O
nor	O
easily	O
ported	O
from	O
,	O
most	O
other	O
systems	O
.	O
</s>
<s>
It	O
retained	O
the	O
original	O
40-bit	O
format	O
floating-point	B-Algorithm
arithmetic	I-Algorithm
library	O
that	O
replaced	O
the	O
notoriously	O
slow	O
one	O
in	O
the	O
system	O
's	O
operating	B-General_Concept
system	I-General_Concept
ROMs	O
,	O
and	O
thus	O
ran	O
math	O
code	O
at	O
the	O
same	O
speed	O
as	O
other	O
platforms	O
,	O
and	O
much	O
faster	O
than	O
Atari	B-Language
BASIC	I-Language
.	O
</s>
<s>
If	O
either	O
was	O
not	O
true	O
,	O
the	O
integer	O
values	O
would	O
be	O
converted	O
to	O
floating-point	B-Algorithm
,	O
use	O
the	O
floating-point	B-Algorithm
code	O
for	O
the	O
calculation	O
,	O
and	O
then	O
be	O
converted	O
back	O
to	O
integer	O
for	O
storage	O
.	O
</s>
<s>
Atari	B-Language
BASIC	I-Language
performed	O
these	O
by	O
placing	O
the	O
line	O
number	O
of	O
the	O
on	O
the	O
execution	O
stack	O
,	O
so	O
when	O
the	O
associated	O
was	O
encountered	O
it	O
could	O
find	O
which	O
line	O
to	O
loop	O
back	O
to	O
.	O
</s>
<s>
In	O
contrast	O
,	O
MS	B-Language
BASIC	I-Language
had	O
always	O
placed	O
the	O
memory	O
location	O
of	O
that	O
line	O
on	O
the	O
stack	O
,	O
allowing	O
it	O
to	O
jump	O
back	O
to	O
the	O
without	O
having	O
to	O
search	O
through	O
the	O
entire	O
program	O
for	O
the	O
matching	O
line	O
.	O
</s>
<s>
This	O
oddity	O
in	O
Atari	B-Language
BASIC	I-Language
is	O
one	O
of	O
the	O
primary	O
reasons	O
for	O
its	O
slow	O
performance	O
,	O
and	O
because	O
this	O
was	O
not	O
true	O
in	O
Atari	B-Language
Microsoft	I-Language
BASIC	I-Language
,	O
it	O
generally	O
ran	O
much	O
faster	O
than	O
Atari	B-Language
BASIC	I-Language
.	O
</s>
<s>
In	O
contrast	O
to	O
Atari	B-Language
BASIC	I-Language
,	O
which	O
parsed	O
and	O
tokenized	O
entire	O
lines	O
when	O
they	O
were	O
typed	O
in	O
,	O
MS	B-Language
BASICs	I-Language
only	O
partially	O
tokenized	O
the	O
source	O
code	O
.	O
</s>
<s>
Depending	O
on	O
the	O
use-case	O
,	O
Atari	B-Language
BASIC	I-Language
's	O
complete	O
tokenization	O
of	O
the	O
line	O
could	O
result	O
in	O
less	O
memory	O
being	O
used	O
to	O
store	O
the	O
program	O
.	O
</s>
<s>
In	O
theory	O
,	O
edit-time	O
compilation	O
should	O
have	O
made	O
Atari	B-Language
BASIC	I-Language
much	O
faster	O
than	O
MS	O
,	O
which	O
re-tokenizes	O
the	O
line	O
every	O
time	O
it	O
is	O
encountered	O
,	O
but	O
this	O
advantage	O
was	O
washed	O
away	O
by	O
the	O
other	O
performance	O
issues	O
noted	O
above	O
.	O
</s>
<s>
MS	B-Language
BASIC	I-Language
did	O
not	O
include	O
a	O
system	O
for	O
entering	O
short	O
forms	O
of	O
keywords	O
,	O
unlike	O
Atari	B-Language
BASIC	I-Language
which	O
allowed	O
them	O
to	O
be	O
abbreviated	O
with	O
a	O
period	O
during	O
entry	O
.	O
</s>
<s>
Atari	B-Language
Microsoft	I-Language
BASIC	I-Language
added	O
a	O
number	O
of	O
new	O
features	O
to	O
take	O
advantage	O
of	O
the	O
platform	O
.	O
</s>
<s>
had	O
been	O
part	O
of	O
the	O
earliest	O
versions	O
of	O
MS	B-Language
BASIC	I-Language
but	O
not	O
widely	O
used	O
.	O
</s>
<s>
Atari	B-Language
Microsoft	I-Language
BASIC	I-Language
included	O
most	O
of	O
the	O
graphics	O
and	O
sound	O
commands	O
from	O
Atari	B-Language
BASIC	I-Language
.	O
</s>
<s>
This	O
means	O
graphics	O
code	O
for	O
Atari	B-Language
BASIC	I-Language
was	O
not	O
compatible	O
.	O
</s>
<s>
Atari	B-Language
Microsoft	I-Language
BASIC	I-Language
added	O
a	O
number	O
of	O
additional	O
commands	O
for	O
handling	O
player/missile	O
graphics	O
and	O
user-defined	O
character	B-General_Concept
sets	I-General_Concept
that	O
were	O
not	O
available	O
in	O
Atari	B-Language
BASIC	I-Language
.	O
</s>
<s>
Atari	B-Language
Microsoft	I-Language
BASIC	I-Language
came	O
in	O
two	O
packages	O
:	O
</s>
<s>
ROM	B-Protocol
cartridge	I-Protocol
–	O
RX8035	O
.	O
</s>
<s>
Since	O
the	O
cartridge	B-Protocol
could	O
only	O
hold	O
16KB	O
,	O
the	O
remaining	O
11KB	O
file	O
was	O
included	O
on	O
an	O
"	O
extension	O
"	O
disk	O
.	O
</s>
<s>
The	O
cartridge	B-Protocol
version	O
was	O
called	O
Atari	B-Language
Microsoft	I-Language
BASIC	I-Language
II	I-Language
.	O
</s>
<s>
Although	O
more	O
feature-filled	O
than	O
Atari	B-Language
BASIC	I-Language
,	O
Microsoft	B-Language
BASIC	I-Language
never	O
had	O
the	O
popularity	O
that	O
Atari	B-Language
BASIC	I-Language
had	O
.	O
</s>
<s>
The	O
cartridge	B-Protocol
version	O
eliminated	O
the	O
first	O
two	O
requirements	O
,	O
but	O
a	O
disk	O
drive	O
was	O
needed	O
for	O
all	O
of	O
its	O
features	O
.	O
</s>
