<s>
The	O
ICL	B-Device
Series	I-Device
39	I-Device
was	O
a	O
range	O
of	O
mainframe	B-Architecture
and	O
minicomputer	B-Architecture
computer	O
systems	O
released	O
by	O
the	O
UK	O
manufacturer	O
ICL	O
in	O
1985	O
.	O
</s>
<s>
The	O
original	O
Series	O
39	O
introduced	O
the	O
"	O
S3L	O
"	O
(	O
whose	O
corrupt	O
pronunciation	O
resulted	O
in	O
the	O
name	O
"	O
Estriel	O
"	O
)	O
processors	O
and	O
microcodes	B-Device
,	O
and	O
a	O
nodal	B-Device
architecture	I-Device
,	O
which	O
is	O
a	O
form	O
of	O
Non-Uniform	B-Operating_System
Memory	I-Operating_System
Access	I-Operating_System
.	O
</s>
<s>
The	O
Series	O
39	O
range	O
was	O
based	O
upon	O
the	O
New	O
Range	O
concept	O
and	O
the	O
VME	B-General_Concept
operating	O
system	O
from	O
the	O
company	O
's	O
ICL	B-Device
2900	I-Device
line	O
,	O
and	O
was	O
introduced	O
as	O
two	O
ranges	O
:	O
</s>
<s>
The	O
original	O
Series	O
39	O
introduced	O
the	O
"	O
S3L	O
"	O
(	O
whose	O
corrupt	O
pronunciation	O
resulted	O
in	O
the	O
name	O
"	O
Estriel	O
"	O
)	O
processors	O
and	O
microcodes	B-Device
,	O
and	O
a	O
nodal	B-Device
architecture	I-Device
(	O
see	O
ICL	B-General_Concept
VME	I-General_Concept
)	O
which	O
is	O
a	O
form	O
of	O
Non-Uniform	B-Operating_System
Memory	I-Operating_System
Access	I-Operating_System
which	O
allowed	O
nodes	B-Protocol
to	O
be	O
up	O
to	O
apart	O
.	O
</s>
<s>
The	O
Series	O
39	O
range	O
introduced	O
Nodal	B-Device
Architecture	I-Device
,	O
a	O
novel	O
implementation	O
of	O
distributed	B-Operating_System
shared	I-Operating_System
memory	I-Operating_System
that	O
can	O
be	O
seen	O
as	O
a	O
hybrid	O
of	O
a	O
multiprocessor	B-Operating_System
system	O
and	O
a	O
cluster	B-Architecture
design	O
.	O
</s>
<s>
Each	O
machine	O
consists	O
of	O
a	O
number	O
of	O
nodes	B-Protocol
,	O
and	O
each	O
node	O
contains	O
its	O
own	O
order-code	O
processor	O
and	O
main	O
memory	O
.	O
</s>
<s>
Discs	O
and	O
other	O
peripherals	O
are	O
shared	O
between	O
nodes	B-Protocol
.	O
</s>
<s>
Nodes	B-Protocol
are	O
connected	O
using	O
a	O
high-speed	O
optical	O
bus	O
(	O
Macrolan	O
)	O
using	O
multiple	O
fibre	O
optic	O
cables	O
,	O
which	O
is	O
used	O
to	O
provide	O
applications	O
with	O
a	O
virtual	O
shared	O
memory	O
.	O
</s>
<s>
Processes	O
which	O
use	O
unshared	O
memory	O
segments	O
(	O
nodal	O
or	O
local	O
)	O
run	O
in	O
complete	O
isolation	O
from	O
other	O
nodes	B-Protocol
and	O
processes	O
.	O
</s>
<s>
The	O
semaphore	B-Operating_System
instructions	I-Operating_System
prove	O
their	O
worth	O
by	O
controlling	O
access	O
to	O
the	O
shared	O
writable	O
memory	O
segments	O
while	O
allowing	O
the	O
contents	O
to	O
be	O
moved	O
around	O
efficiently	O
.	O
</s>
<s>
Overall	O
,	O
a	O
well	O
configured	O
Series	O
39	O
with	O
VME	B-General_Concept
had	O
an	O
architecture	O
which	O
can	O
provide	O
a	O
significant	O
degree	O
of	O
proofing	O
against	O
disasters	O
,	O
a	O
nod	O
to	O
the	O
abortive	O
VME/T	O
ideas	O
of	O
the	O
previous	O
decade	O
.	O
</s>
<s>
All	O
Series	O
39	O
machines	O
also	O
featured	O
a	O
Node	O
Support	O
Computer	O
(	O
NSC	O
)	O
hosted	O
on	O
their	O
Storage	O
Motherboards	O
-	O
this	O
was	O
x86	O
architecture	O
and	O
acted	O
much	O
like	O
today	O
's	O
ILO	O
or	O
DRAC	O
cards	O
on	O
HP/Dell	O
Servers	O
and	O
allowed	O
Support	O
Staff	O
to	O
manage	O
the	O
Nodes	B-Protocol
remotely	O
including	O
the	O
ability	O
to	O
completely	O
stop	O
and	O
restart	O
the	O
main	O
Nodes	B-Protocol
.	O
</s>
<s>
A	O
mid-life	O
upgrade	O
to	O
"	O
S3X	O
"	O
(	O
"	O
Essex	O
"	O
)	O
processors	O
and	O
microcodes	B-Device
saw	O
:	O
</s>
<s>
The	O
Series	O
39	O
SX/DX	O
was	O
replaced	O
by	O
the	O
Trimetra	O
system	O
(	O
initially	O
the	O
SY/DY	O
,	O
and	O
then	O
the	O
DL/SL	O
ranges	O
)	O
,	O
which	O
made	O
more	O
use	O
of	O
industry	O
standard	O
hardware	O
and	O
allowed	O
for	O
both	O
Windows	B-Application
and	O
VME	B-General_Concept
nodes	B-Protocol
on	O
the	O
same	O
system	O
.	O
</s>
<s>
Trimetra	O
in	O
turn	O
was	O
replaced	O
by	O
Fujitsu	O
's	O
mainframe	B-Architecture
platform	O
,	O
Nova	O
,	O
which	O
emulates	O
the	O
Trimetra	O
architecture	O
on	O
generic	O
Unisys	O
ES7000	B-Application
Intel-based	O
server	O
hardware	O
.	O
</s>
<s>
Nova	O
itself	O
was	O
phased	O
out	O
in	O
2007	O
and	O
replaced	O
with	O
SuperNova	O
,	O
which	O
runs	O
OpenVME	B-General_Concept
on	O
top	O
of	O
Windows	B-Application
Server	O
or	O
Linux	O
,	O
using	O
as	O
few	O
as	O
two	O
CPUs	O
on	O
generic	O
Wintel	B-Device
server	O
hardware	O
.	O
</s>
<s>
The	O
transition	O
of	O
the	O
"	O
ICL	O
mainframe	B-Architecture
"	O
to	O
a	O
pure	O
software	O
product	O
was	O
thus	O
complete	O
,	O
enabling	O
Fujitsu	O
to	O
concentrate	O
on	O
VME	B-General_Concept
support	O
and	O
development	O
without	O
having	O
to	O
keep	O
up	O
with	O
hardware	O
technology	O
.	O
</s>
