<s>
MSX	B-Language
BASIC	I-Language
is	O
a	O
dialect	O
of	O
the	O
BASIC	B-Language
programming	I-Language
language	I-Language
.	O
</s>
<s>
It	O
is	O
an	O
extended	O
version	O
of	O
Microsoft	O
's	O
MBASIC	B-Language
Version	O
4.5	O
,	O
adding	O
support	O
for	O
graphic	O
,	O
music	O
,	O
and	O
various	O
peripherals	O
attached	O
to	O
MSX	B-Operating_System
microcomputers	B-Architecture
.	O
</s>
<s>
Generally	O
,	O
MSX	B-Language
BASIC	I-Language
is	O
designed	O
to	O
follow	O
GW-BASIC	B-Language
,	O
released	O
the	O
same	O
year	O
for	O
IBM	B-Device
PCs	I-Device
and	O
clones	O
.	O
</s>
<s>
During	O
the	O
creation	O
of	O
MSX	B-Language
BASIC	I-Language
,	O
effort	O
was	O
made	O
to	O
make	O
the	O
system	O
flexible	O
and	O
expandable	O
.	O
</s>
<s>
MSX	B-Language
BASIC	I-Language
came	O
bundled	O
in	O
the	O
ROM	B-Device
of	O
all	O
MSX	B-Operating_System
computers	O
.	O
</s>
<s>
At	O
system	O
start-up	O
MSX	B-Language
BASIC	I-Language
is	O
invoked	O
,	O
causing	O
its	O
command	O
prompt	O
to	O
be	O
displayed	O
,	O
unless	O
other	O
software	O
placed	O
in	O
ROM	B-Device
takes	O
control	O
(	O
which	O
is	O
the	O
typical	O
case	O
of	O
game	B-Protocol
cartridges	I-Protocol
and	O
disk	O
interfaces	O
,	O
the	O
latter	O
causing	O
the	O
MSX-DOS	B-Operating_System
prompt	O
to	O
be	O
shown	O
if	O
there	O
is	O
a	O
disk	O
present	O
which	O
contains	O
the	O
DOS	O
system	O
files	O
)	O
.	O
</s>
<s>
When	O
MSX	B-Language
BASIC	I-Language
is	O
invoked	O
,	O
the	O
ROM	B-Device
code	O
for	O
BIOS	B-Operating_System
and	O
the	O
BASIC	B-Language
interpreter	I-Language
itself	O
are	O
visible	O
on	O
the	O
lower	O
32K	O
of	O
the	O
Z80	B-General_Concept
addressing	O
space	O
.	O
</s>
<s>
The	O
upper	O
32K	O
are	O
set	O
to	O
RAM	B-Architecture
,	O
of	O
which	O
about	O
23K	O
to	O
28K	O
are	O
available	O
for	O
BASIC	O
code	O
and	O
data	O
(	O
the	O
exact	O
amount	O
depends	O
on	O
the	O
presence	O
of	O
disk	O
controller	O
and	O
on	O
the	O
MSX-DOS	B-Operating_System
kernel	B-Operating_System
version	O
)	O
.	O
</s>
<s>
MSX	B-Language
BASIC	I-Language
development	O
environment	O
is	O
very	O
similar	O
to	O
other	O
versions	O
of	O
Microsoft	O
BASIC	O
.	O
</s>
<s>
It	O
has	O
a	O
command	O
line-based	O
Integrated	B-Application
Development	I-Application
Environment	I-Application
(	O
IDE	O
)	O
system	O
;	O
all	O
program	O
lines	O
must	O
be	O
numbered	O
,	O
all	O
non-numbered	O
lines	O
are	O
considered	O
to	O
be	O
commands	O
in	O
direct	O
mode	O
(	O
i.e.	O
,	O
to	O
be	O
executed	O
immediately	O
)	O
.	O
</s>
<s>
The	O
user	O
interface	O
is	O
entirely	O
command-line-based	O
.	O
</s>
<s>
Every	O
new	O
version	O
of	O
the	O
MSX	B-Operating_System
computer	O
was	O
bundled	O
with	O
an	O
updated	O
version	O
of	O
MSX	B-Language
BASIC	I-Language
.	O
</s>
<s>
All	O
versions	O
are	O
backward	B-General_Concept
compatible	I-General_Concept
and	O
provide	O
new	O
capabilities	O
to	O
fully	O
explore	O
the	O
new	O
and	O
extended	O
hardware	O
found	O
on	O
the	O
newer	O
MSX	B-Operating_System
computers	O
.	O
</s>
<s>
Note	O
that	O
the	O
Brazilian	O
MSX	B-Operating_System
"	O
clones	O
"	O
by	O
Sharp	O
and	O
Gradiente	O
show	O
other	O
versions	O
of	O
MSX	B-Language
BASIC	I-Language
(	O
on	O
the	O
Sharps	O
even	O
called	O
HOT-BASIC	O
)	O
,	O
but	O
they	O
're	O
basically	O
just	O
unlicensed	O
MSX	B-Language
BASIC	I-Language
1.0	O
.	O
</s>
<s>
Added	O
support	O
for	O
using	O
the	O
lower	O
32K	O
RAM	B-Architecture
of	O
the	O
computer	O
(	O
not	O
directly	O
visible	O
because	O
the	O
BIOS	B-Operating_System
and	O
BASIC	B-Language
interpreter	I-Language
ROMs	O
take	O
over	O
the	O
addressing	O
space	O
)	O
as	O
a	O
limited	O
RAM	B-Architecture
disk	O
(	O
only	O
certain	O
types	O
of	O
files	O
could	O
be	O
saved	O
)	O
.	O
</s>
<s>
MSX	B-Language
BASIC	I-Language
2.1	O
supports	O
using	O
the	O
memory	O
mapper	O
(	O
if	O
available	O
on	O
the	O
machine	O
)	O
to	O
expand	O
this	O
RAM	B-Architecture
disk	O
to	O
almost	O
90	O
KB	O
.	O
</s>
<s>
MSX	B-Language
BASIC	I-Language
2.1	O
exists	O
on	O
computers	O
like	O
the	O
Philips	O
MSX2	B-Operating_System
machines	O
(	O
except	O
for	O
the	O
VG	O
8230	O
)	O
,	O
the	O
Yamaha	O
YIS-805	O
and	O
Sanyo	O
MPC-2300	O
.	O
</s>
<s>
Since	O
MSX	B-Language
BASIC	I-Language
was	O
meant	O
to	O
be	O
expandable	O
from	O
inception	O
,	O
it	O
was	O
possible	O
to	O
write	O
add-on	O
modules	O
quite	O
easily	O
.	O
</s>
<s>
Support	O
for	O
specific	O
hardware	O
was	O
commonly	O
added	O
by	O
means	O
of	O
expansion	O
cartridges	B-Protocol
,	O
which	O
also	O
served	O
as	O
the	O
interface	O
to	O
the	O
hardware	O
in	O
question	O
.	O
</s>
<s>
MSX	B-Operating_System
Disk-BASIC	O
is	O
an	O
example	O
,	O
bundled	O
in	O
the	O
cartridge	B-Protocol
that	O
provides	O
the	O
hardware	O
interface	O
to	O
the	O
disk	O
drives	O
,	O
it	O
adds	O
commands	O
to	O
access	O
the	O
floppy	O
disk	O
drives	O
.	O
</s>
