<s>
Southampton	B-Language
BASIC	I-Language
System	I-Language
(	O
SOBS	B-Language
)	O
was	O
a	O
dialect	O
of	O
the	O
BASIC	O
programming	O
language	O
developed	O
for	O
and	O
used	O
on	O
ICT	B-Device
1900	I-Device
series	I-Device
computers	O
in	O
the	O
late	O
1960s	O
and	O
early	O
1970s	O
;	O
it	O
was	O
implemented	O
as	O
an	O
incremental	O
BASIC	B-Language
interpreter	I-Language
under	O
the	O
MINIMOP	B-Operating_System
operating	O
system	O
at	O
the	O
University	O
of	O
Southampton	O
and	O
also	O
ran	O
under	O
MAXIMOP	B-Operating_System
.	O
</s>
<s>
In	O
common	O
with	O
many	O
early	O
implementations	O
of	O
BASIC	O
,	O
SOBS	B-Language
needed	O
lines	O
to	O
have	O
line	B-Application
numbers	I-Application
,	O
both	O
to	O
allow	O
a	O
user	O
to	O
add	O
new	O
lines	O
to	O
the	O
program	O
in	O
the	O
desired	O
place	O
and	O
also	O
as	O
targets	O
for	O
GOTO	O
and	O
GOSUB	O
statements	O
.	O
</s>
<s>
A	O
RENUMBER	B-Application
facility	O
was	O
available	O
to	O
allow	O
for	O
sections	O
of	O
the	O
code	O
to	O
be	O
renumbered	O
,	O
by	O
default	O
in	O
increments	O
of	O
10	O
,	O
to	O
allow	O
more	O
space	O
in	O
the	O
middle	O
of	O
a	O
program	O
.	O
</s>
<s>
Other	O
than	O
line	B-Application
numbers	I-Application
,	O
all	O
numeric	B-Algorithm
values	O
were	O
represented	O
internally	O
as	O
floating	B-Algorithm
point	I-Algorithm
.	O
</s>
<s>
FOR	O
var	O
=	O
start	O
TO	O
end	O
[	O
STEP	O
incr ]	O
Perform	O
a	O
set	O
of	O
statements	O
repeatedly	O
for	O
varying	O
values	O
of	O
var	O
GOSUB	O
line	O
Call	O
a	O
subroutine	O
at	O
a	O
given	O
line	B-Application
number	I-Application
;	O
flow	O
would	O
return	O
to	O
the	O
next	O
statement	O
when	O
a	O
RETURN	O
was	O
executed	O
.	O
</s>
<s>
GOTO	O
line	O
Unconditional	O
branch	O
to	O
a	O
given	O
line	B-Application
number	I-Application
.	O
</s>
<s>
The	O
THEN	O
and	O
ELSE	O
parts	O
could	O
only	O
give	O
line	B-Application
numbers	I-Application
to	O
go	O
to	O
.	O
</s>
<s>
Variable	O
names	O
for	O
numeric	B-Algorithm
values	O
were	O
either	O
a	O
single	O
letter	O
,	O
or	O
a	O
single	O
letter	O
followed	O
by	O
a	O
single	O
numeric	B-Algorithm
digit	O
,	O
thus	O
allowing	O
for	O
286	O
discreet	O
variables	O
in	O
total	O
.	O
</s>
<s>
A	O
limited	O
number	O
of	O
numeric	B-Algorithm
functions	O
were	O
provided	O
,	O
all	O
of	O
which	O
took	O
one	O
numeric	B-Algorithm
parameter	O
:	O
</s>
<s>
Support	O
for	O
handling	O
arrays	O
of	O
data	O
was	O
relatively	O
strong	O
,	O
with	O
MAT	O
statements	O
able	O
to	O
read	O
an	O
entire	O
array	O
from	O
DATA	O
statements	O
,	O
and	O
perform	O
useful	O
matrix	B-Architecture
operations	O
such	O
as	O
matrix	B-Architecture
addition	O
,	O
matrix	B-Architecture
subtraction	O
,	O
matrix	B-Architecture
multiplication	O
,	O
and	O
finding	O
the	O
inverse	O
matrix	B-Architecture
for	O
a	O
square	B-Algorithm
matrix	I-Algorithm
.	O
</s>
<s>
SOBS	B-Language
had	O
primitive	O
debugging	O
capabilities	O
,	O
limited	O
mostly	O
to	O
the	O
TRACE	O
statement	O
.	O
</s>
<s>
TRACE	O
ON	O
would	O
cause	O
the	O
interpreter	O
to	O
print	O
each	O
line	B-Application
number	I-Application
as	O
it	O
was	O
executed	O
.	O
</s>
