<s>
BESM	B-Device
( БЭСМ	O
)	O
is	O
the	O
name	O
of	O
a	O
series	O
of	O
Soviet	O
mainframe	B-Architecture
computers	I-Architecture
built	O
in	O
1950	O
–	O
60s	O
.	O
</s>
<s>
The	O
series	O
began	O
as	O
a	O
successor	O
to	O
MESM	B-Device
(	O
"	O
Malaya	O
Elektronno-Schetnaya	O
Mashina	O
"	O
,	O
"	O
Small	O
Electronic	O
Computing	O
Machine	O
"	O
)	O
.	O
</s>
<s>
MESM	B-Device
was	O
built	O
between	O
1948	O
and	O
1951	O
and	O
was	O
one	O
of	O
the	O
first	O
electronic	O
computers	O
produced	O
in	O
continental	O
Europe	O
.	O
</s>
<s>
The	O
BESM	B-Device
series	O
included	O
six	O
models	O
.	O
</s>
<s>
BESM-1	B-Device
,	O
originally	O
referred	O
to	O
as	O
simply	O
the	O
BESM	B-Device
or	O
BESM	B-Device
AN	O
(	O
"	O
BESM	B-Device
Akademii	O
Nauk	O
"	O
,	O
BESM	B-Device
of	O
the	O
Academy	O
of	O
Sciences	O
)	O
,	O
was	O
completed	O
in	O
1952	O
.	O
</s>
<s>
Only	O
one	O
BESM-1	B-Device
machine	O
was	O
built	O
.	O
</s>
<s>
The	O
floating-point	B-Algorithm
numbers	I-Algorithm
were	O
represented	O
as	O
39-bit	O
words	O
:	O
32	O
bits	O
for	O
the	O
mantissa	B-Algorithm
,	O
one	O
bit	O
for	O
sign	O
,	O
and	O
1	O
+	O
5	O
bits	O
for	O
the	O
exponent	O
.	O
</s>
<s>
BESM-1	B-Device
had	O
1024	O
words	O
of	O
read	B-General_Concept
–	I-General_Concept
write	I-General_Concept
memory	I-General_Concept
using	O
ferrite	O
cores	O
,	O
and	O
1024	O
words	O
of	O
read-only	B-Device
memory	I-Device
based	O
on	O
semiconducting	O
diodes	O
.	O
</s>
<s>
It	O
also	O
had	O
external	O
storage	O
:	O
four	O
magnetic	O
tape	O
units	O
of	O
30,000	O
words	O
each	O
,	O
and	O
fast	O
magnetic	B-General_Concept
drum	I-General_Concept
storage	O
with	O
a	O
capacity	O
of	O
5120	O
words	O
and	O
an	O
access	O
rate	O
of	O
800	O
words/second	O
.	O
</s>
<s>
BESM-2	O
also	O
used	O
vacuum	O
tubes	O
.	O
</s>
<s>
BESM-3M	O
and	O
BESM-4	B-Device
were	O
built	O
using	O
transistors	B-Application
.	O
</s>
<s>
Thirty	O
BESM-4	B-Device
machines	O
were	O
built	O
.	O
</s>
<s>
BESM-4	B-Device
was	O
used	O
to	O
create	O
the	O
first	O
ever	O
computer	O
animation	O
.	O
</s>
<s>
EPSILON	O
(	O
a	O
macro	O
language	O
with	O
high	O
level	O
features	O
including	O
strings	O
and	O
lists	O
,	O
developed	O
by	O
Andrey	O
Ershov	O
at	O
Novosibirsk	O
in	O
1967	O
)	O
was	O
used	O
to	O
implement	O
ALGOL	B-Language
68	I-Language
on	O
the	O
M-220	O
.	O
</s>
<s>
The	O
BESM-6	B-Device
was	O
the	O
most	O
well-known	O
and	O
influential	O
model	O
of	O
the	O
series	O
designed	O
at	O
the	O
Institute	O
of	O
Precision	O
Mechanics	O
and	O
Computer	O
Engineering	O
.	O
</s>
