<s>
Autocode	B-Language
is	O
the	O
name	O
of	O
a	O
family	O
of	O
"	O
simplified	O
coding	O
systems	O
"	O
,	O
later	O
called	O
programming	B-Language
languages	I-Language
,	O
devised	O
in	O
the	O
1950s	O
and	O
1960s	O
for	O
a	O
series	O
of	O
digital	O
computers	O
at	O
the	O
Universities	O
of	O
Manchester	O
,	O
Cambridge	O
and	O
London	O
.	O
</s>
<s>
Autocode	B-Language
was	O
a	O
generic	O
term	O
;	O
the	O
autocodes	B-Language
for	O
different	O
machines	O
were	O
not	O
necessarily	O
closely	O
related	O
as	O
are	O
,	O
for	O
example	O
,	O
the	O
different	O
versions	O
of	O
the	O
single	O
language	O
Fortran	B-Application
.	O
</s>
<s>
Today	O
the	O
term	O
is	O
used	O
to	O
refer	O
to	O
the	O
family	O
of	O
early	O
languages	O
descended	O
from	O
the	O
Manchester	B-Device
Mark	I-Device
1	I-Device
autocoder	O
systems	O
,	O
which	O
were	O
generally	O
similar	O
.	O
</s>
<s>
In	O
the	O
1960s	O
,	O
the	O
term	O
autocoders	O
was	O
used	O
more	O
generically	O
as	O
to	O
refer	O
to	O
any	O
high-level	B-Language
programming	I-Language
language	I-Language
using	O
a	O
compiler	B-Language
.	O
</s>
<s>
Examples	O
of	O
languages	O
referred	O
to	O
as	O
autocodes	B-Language
are	O
COBOL	B-Application
and	O
Fortran	B-Application
.	O
</s>
<s>
The	O
first	O
autocode	B-Language
and	O
its	O
compiler	B-Language
were	O
developed	O
by	O
Alick	O
Glennie	O
in	O
1952	O
for	O
the	O
Mark	O
1	O
computer	O
at	O
the	O
University	O
of	O
Manchester	O
and	O
is	O
considered	O
by	O
some	O
to	O
be	O
the	O
first	O
compiled	B-Language
programming	O
language	O
.	O
</s>
<s>
Below	O
is	O
an	O
example	O
of	O
Glennie	O
's	O
Autocode	B-Language
function	O
which	O
calculates	O
the	O
formula	O
:	O
.	O
</s>
<s>
User	O
's	O
manual	O
of	O
Glennie	O
's	O
Autocode	B-Language
Compiler	B-Language
mentioned	O
that	O
"	O
the	O
loss	O
of	O
efficiency	O
is	O
no	O
more	O
than	O
10%	O
"	O
.	O
</s>
<s>
Impact	O
of	O
Glennie	O
's	O
Autocode	B-Language
on	O
other	O
Manchester	O
users	O
 '	O
programming	O
habits	O
was	O
negligible	O
.	O
</s>
<s>
It	O
was	O
n't	O
even	O
mentioned	O
in	O
Brooker	O
's	O
1958	O
paper	O
called	O
"	O
The	O
Autocode	B-Language
Programs	O
developed	O
for	O
the	O
Manchester	O
University	O
Computers	O
"	O
.	O
</s>
<s>
The	O
second	O
autocode	B-Language
for	O
the	O
Mark	O
1	O
was	O
planned	O
in	O
1954	O
and	O
developed	O
by	O
R	O
.	O
A	O
.	O
Brooker	O
in	O
1955	O
and	O
was	O
called	O
the	O
"	O
Mark	B-Language
1	I-Language
Autocode	I-Language
"	O
.	O
</s>
<s>
Brooker	O
's	O
Autocode	B-Language
removed	O
two	O
main	O
difficulties	O
of	O
Mark	O
1	O
's	O
programmer	O
:	O
scaling	O
and	O
management	O
of	O
two-level	O
storage	O
.	O
</s>
<s>
Brooker	O
also	O
developed	O
an	O
autocode	B-Language
for	O
the	B-Device
Ferranti	I-Device
Mercury	I-Device
in	O
the	O
1950s	O
in	O
conjunction	O
with	O
the	O
University	O
of	O
Manchester	O
.	O
</s>
<s>
Mercury	B-Language
Autocode	I-Language
had	O
a	O
limited	O
repertoire	O
of	O
variables	O
a-z	O
and	O
a'-z'	O
and	O
,	O
in	O
some	O
ways	O
resembled	O
early	O
versions	O
of	O
the	O
later	O
Dartmouth	B-Language
BASIC	I-Language
language	O
.	O
</s>
<s>
It	O
pre-dated	O
ALGOL	B-Language
,	O
having	O
no	O
concept	O
of	O
stacks	O
and	O
hence	O
no	O
recursion	O
or	O
dynamically-allocated	B-General_Concept
arrays	B-Data_Structure
.	O
</s>
<s>
In	O
order	O
to	O
overcome	O
the	O
relatively	O
small	O
store	O
size	O
available	O
on	O
Mercury	B-Device
,	O
large	O
programs	O
were	O
written	O
as	O
distinct	O
"	O
chapters	O
"	O
,	O
each	O
of	O
which	O
constituted	O
an	O
overlay	B-General_Concept
.	O
</s>
<s>
This	O
concept	O
of	O
overlays	B-General_Concept
from	O
drum	B-General_Concept
under	O
user	O
control	O
became	O
common	O
until	O
virtual	B-Architecture
memory	I-Architecture
became	O
available	O
in	O
later	O
machines	O
.	O
</s>
<s>
Slightly	O
different	O
dialects	O
of	O
Mercury	B-Language
Autocode	I-Language
were	O
implemented	O
for	O
the	O
Ferranti	B-Device
Atlas	I-Device
(	O
distinct	O
from	O
the	O
later	O
Atlas	B-Device
Autocode	B-Language
)	O
and	O
the	O
ICT	B-Device
1300	I-Device
and	O
1900	B-Device
range	O
.	O
</s>
<s>
The	O
version	O
for	O
the	O
EDSAC	B-Device
2	I-Device
was	O
devised	O
by	O
David	O
Hartley	O
of	O
University	O
of	O
Cambridge	O
Mathematical	O
Laboratory	O
in	O
1961	O
.	O
</s>
<s>
Known	O
as	O
EDSAC	B-Device
2	I-Device
Autocode	B-Language
,	O
it	O
was	O
a	O
straight	O
development	O
from	O
Mercury	B-Language
Autocode	I-Language
adapted	O
for	O
local	O
circumstances	O
,	O
and	O
was	O
noted	O
for	O
its	O
object	O
code	O
optimisation	O
and	O
source-language	O
diagnostics	O
which	O
were	O
advanced	O
for	O
the	O
time	O
.	O
</s>
<s>
A	O
version	O
was	O
developed	O
for	O
the	O
successor	O
Titan	B-Device
(	O
the	O
prototype	O
Atlas	B-Device
2	O
computer	O
)	O
as	O
a	O
temporary	O
stop-gap	O
while	O
a	O
more	O
substantially	O
advanced	O
language	O
known	O
as	O
CPL	B-Language
was	O
being	O
developed	O
.	O
</s>
<s>
CPL	B-Language
was	O
never	O
completed	O
but	O
did	O
give	O
rise	O
to	O
BCPL	B-Language
(	O
developed	O
by	O
M	O
.	O
Richards	O
)	O
,	O
which	O
in	O
turn	O
led	O
to	O
B	B-Language
and	O
ultimately	O
C	B-Language
.	O
A	O
contemporary	O
but	O
separate	O
thread	O
of	O
development	O
,	O
Atlas	B-Device
Autocode	B-Language
was	O
developed	O
for	O
the	O
University	O
of	O
Manchester	B-Device
Atlas	I-Device
1	O
machine	O
.	O
</s>
