<s>
CESIL	B-Language
,	O
or	O
Computer	O
Education	O
in	O
Schools	O
Instruction	O
Language	O
,	O
is	O
a	O
programming	O
language	O
designed	O
to	O
introduce	O
pupils	O
in	O
British	O
secondary	O
schools	O
to	O
elementary	O
computer	B-General_Concept
programming	I-General_Concept
.	O
</s>
<s>
CESIL	B-Language
was	O
developed	O
by	O
ICL	O
as	O
part	O
of	O
the	O
CES	O
project	O
,	O
and	O
introduced	O
in	O
1974	O
.	O
</s>
<s>
In	O
those	O
days	O
,	O
very	O
few	O
if	O
any	O
schools	O
had	O
computers	O
,	O
so	O
pupils	O
would	O
write	O
programs	O
on	O
coding	O
sheets	O
,	O
which	O
would	O
then	O
be	O
transferred	O
to	O
punched	B-Architecture
cards	I-Architecture
or	O
paper	O
tape	O
.	O
</s>
<s>
Typically	O
,	O
this	O
would	O
be	O
sent	O
to	O
run	O
on	O
a	O
mainframe	B-Architecture
computer	I-Architecture
,	O
with	O
the	O
output	O
from	O
a	O
line	O
printer	O
being	O
returned	O
later	O
.	O
</s>
<s>
Because	O
CESIL	B-Language
was	O
not	O
designed	O
as	O
an	O
interactive	O
language	O
,	O
there	O
is	O
no	O
facility	O
to	O
input	O
data	O
in	O
real	O
time	O
.	O
</s>
<s>
The	O
fundamental	O
principle	O
of	O
CESIL	B-Language
is	O
the	O
use	O
of	O
a	O
single	O
accumulator	B-General_Concept
,	O
which	O
handles	O
mathematical	O
operations	O
.	O
</s>
<s>
Numeric	O
values	O
are	O
stored	O
in	O
variables	O
,	O
which	O
in	O
CESIL	B-Language
are	O
referred	O
to	O
as	O
store	O
locations	O
.	O
</s>
<s>
CESIL	B-Language
only	O
works	O
with	O
integers	O
,	O
and	O
results	O
from	O
DIVIDE	O
operations	O
are	O
rounded	O
if	O
necessary	O
.	O
</s>
<s>
There	O
is	O
no	O
facility	O
for	O
data	B-General_Concept
structures	I-General_Concept
such	O
as	O
arrays	B-Data_Structure
,	O
nor	O
for	O
string	O
handling	O
,	O
though	O
string	O
constants	O
can	O
be	O
output	O
by	O
means	O
of	O
the	O
PRINT	O
instruction	O
.	O
</s>
<s>
IN	O
–	O
reads	O
the	O
next	O
value	O
from	O
the	O
data	O
,	O
and	O
stores	O
it	O
in	O
the	O
accumulator	B-General_Concept
.	O
</s>
<s>
OUT	O
–	O
prints	O
the	O
current	O
value	O
of	O
the	O
accumulator	B-General_Concept
.	O
</s>
<s>
LOAD	O
location	O
or	O
LOAD	O
constant	O
–	O
copies	O
the	O
value	O
of	O
the	O
given	O
location	O
or	O
constant	O
to	O
the	O
accumulator	B-General_Concept
.	O
</s>
<s>
STORE	O
location	O
–	O
copies	O
the	O
contents	O
of	O
the	O
accumulator	B-General_Concept
to	O
the	O
given	O
location	O
.	O
</s>
<s>
ADD	O
location	O
or	O
ADD	O
constant	O
–	O
adds	O
the	O
value	O
of	O
the	O
given	O
location	O
or	O
constant	O
to	O
the	O
accumulator	B-General_Concept
.	O
</s>
<s>
SUBTRACT	O
location	O
or	O
SUBTRACT	O
constant	O
–	O
subtracts	O
the	O
value	O
of	O
the	O
given	O
location	O
or	O
constant	O
from	O
the	O
accumulator	B-General_Concept
.	O
</s>
<s>
MULTIPLY	O
location	O
or	O
MULTIPLY	O
constant	O
–	O
multiplies	O
the	O
accumulator	B-General_Concept
by	O
the	O
value	O
of	O
the	O
given	O
location	O
or	O
constant	O
.	O
</s>
<s>
DIVIDE	O
location	O
or	O
DIVIDE	O
constant	O
–	O
divides	O
the	O
accumulator	B-General_Concept
by	O
the	O
value	O
of	O
the	O
given	O
location	O
or	O
constant	O
.	O
</s>
<s>
In	O
each	O
case	O
,	O
the	O
result	O
of	O
the	O
operation	O
is	O
stored	O
in	O
the	O
accumulator	B-General_Concept
,	O
replacing	O
the	O
previous	O
value	O
.	O
</s>
<s>
JINEG	O
label	O
(	O
Jump	O
If	O
NEGative	O
)	O
–	O
transfers	O
control	O
to	O
location	O
labelled	O
if	O
the	O
accumulator	B-General_Concept
contains	O
a	O
negative	O
value	O
.	O
</s>
<s>
JIZERO	O
label	O
(	O
Jump	O
If	O
ZERO	O
)	O
–	O
transfers	O
control	O
to	O
location	O
labelled	O
if	O
the	O
accumulator	B-General_Concept
contains	O
zero	O
.	O
</s>
<s>
Three	O
special	O
symbols	O
are	O
used	O
in	O
CESIL	B-Language
at	O
the	O
beginnings	O
of	O
lines	O
.	O
</s>
<s>
An	O
emulator	O
for	O
CESIL	B-Language
,	O
designed	O
to	O
run	O
on	O
Windows	O
and	O
called	O
Visual	O
CESIL	B-Language
,	O
is	O
available	O
as	O
freeware	O
.	O
</s>
<s>
An	O
interpreter	O
for	O
CESIL	B-Language
,	O
designed	O
to	O
run	O
on	O
the	O
Android	O
platform	O
and	O
called	O
Wyrm	O
CESIL	B-Language
,	O
is	O
available	O
as	O
free	O
to	O
install	O
.	O
</s>
