<s>
The	O
Orion	O
was	O
a	O
mid-range	O
mainframe	B-Architecture
computer	I-Architecture
introduced	O
by	O
Ferranti	O
in	O
1959	O
and	O
installed	O
for	O
the	O
first	O
time	O
in	O
1961	O
.	O
</s>
<s>
Ferranti	O
positioned	O
Orion	O
to	O
be	O
their	O
primary	O
offering	O
during	O
the	O
early	O
1960s	O
,	O
complementing	O
their	O
high-end	O
Atlas	B-Device
and	O
smaller	O
systems	O
like	O
the	O
Sirius	B-Device
and	O
Argus	B-Device
.	O
</s>
<s>
The	O
Orion	O
was	O
based	O
on	O
a	O
new	O
type	O
of	O
logic	O
circuit	O
known	O
as	O
"	O
Neuron	O
"	O
and	O
included	O
built-in	O
multitasking	B-Operating_System
support	O
,	O
one	O
of	O
the	O
earliest	O
commercial	O
machines	O
to	O
do	O
so	O
(	O
the	O
KDF9	B-Device
being	O
a	O
contemporary	O
)	O
.	O
</s>
<s>
The	O
division	O
was	O
sold	O
to	O
International	O
Computers	O
and	O
Tabulators	O
(	O
ICT	O
)	O
,	O
who	O
selected	O
the	O
Canadian	O
Ferranti-Packard	B-Device
6000	I-Device
as	O
their	O
mid-range	O
offering	O
,	O
ending	O
further	O
sales	O
of	O
the	O
Orion	O
2	O
.	O
</s>
<s>
During	O
the	O
1950s	O
transistors	B-Application
were	O
expensive	O
and	O
relatively	O
fragile	O
devices	O
.	O
</s>
<s>
Similar	O
to	O
magnetic	O
core	B-General_Concept
memory	I-General_Concept
,	O
or	O
"	O
cores	O
"	O
,	O
magnetic	O
amplifiers	O
used	O
small	O
toroids	O
of	O
ferrite	O
as	O
a	O
switching	O
element	O
.	O
</s>
<s>
Unlike	O
digital	O
logic	O
based	O
on	O
tubes	O
or	O
transistors	B-Application
,	O
which	O
uses	O
defined	O
voltages	O
to	O
represent	O
values	O
,	O
magnetic	O
amplifiers	O
based	O
their	O
logic	O
values	O
on	O
defined	O
current	O
values	O
.	O
</s>
<s>
This	O
was	O
widely	O
used	O
in	O
the	O
"	O
best	O
two	O
out	O
of	O
three	O
"	O
circuits	O
that	O
were	O
used	O
in	O
binary	O
adders	O
,	O
which	O
could	O
reduce	O
the	O
component	O
count	O
of	O
the	O
ALU	B-General_Concept
considerably	O
.	O
</s>
<s>
In	O
the	O
late	O
1950s	O
new	O
techniques	O
were	O
introduced	O
in	O
transistor	B-Application
manufacture	O
that	O
led	O
to	O
a	O
rapid	O
fall	O
in	O
prices	O
while	O
reliability	O
shot	O
up	O
.	O
</s>
<s>
Few	O
machines	O
using	O
the	O
circuits	O
reached	O
the	O
market	O
,	O
the	O
best	O
known	O
examples	O
being	O
the	O
mostly-magnetic	O
UNIVAC	B-Device
Solid	I-Device
State	I-Device
(	O
1959	O
)	O
and	O
the	O
mostly	O
transistorized	O
English	B-Device
Electric	I-Device
KDF9	I-Device
(	O
1964	O
)	O
.	O
</s>
<s>
The	O
Ferranti	O
Computer	O
Department	O
in	O
West	O
Gorton	O
,	O
Manchester	O
had	O
originally	O
been	O
set	O
up	O
as	O
an	O
industrial	O
partner	O
of	O
Manchester	O
University	O
's	O
pioneering	O
computer	O
research	O
lab	O
,	O
commercializing	O
their	O
Manchester	B-Device
Mark	I-Device
1	I-Device
and	O
several	O
follow-on	O
designs	O
.	O
</s>
<s>
Like	O
most	O
teams	O
,	O
they	O
decided	O
to	O
abandon	O
them	O
when	O
transistors	B-Application
improved	O
.	O
</s>
<s>
One	O
member	O
of	O
the	O
lab	O
,	O
Ken	O
Johnson	O
,	O
proposed	O
a	O
new	O
type	O
of	O
transistor-based	O
logic	O
that	O
followed	O
the	O
same	O
conventions	O
as	O
the	O
magnetic	O
amplifiers	O
,	O
namely	O
that	O
binary	O
logic	O
was	O
based	O
on	O
known	O
currents	O
instead	O
of	O
voltages	O
.	O
</s>
<s>
Better	O
yet	O
,	O
the	O
system	O
often	O
required	O
only	O
one	O
transistor	B-Application
per	O
logic	O
element	O
,	O
whereas	O
conventional	O
voltage-based	O
logic	O
would	O
require	O
two	O
or	O
more	O
.	O
</s>
<s>
Although	O
transistors	B-Application
were	O
falling	O
in	O
price	O
they	O
were	O
still	O
expensive	O
,	O
so	O
a	O
Neuron-based	O
machine	O
might	O
offer	O
similar	O
performance	O
at	O
a	O
much	O
lower	O
price	O
than	O
a	O
machine	O
based	O
on	O
traditional	O
transistor	B-Application
logic	O
.	O
</s>
<s>
The	O
result	O
was	O
the	O
Sirius	B-Device
,	O
which	O
was	O
announced	O
on	O
19	O
May	O
1959	O
with	O
claims	O
that	O
it	O
was	O
the	O
smallest	O
and	O
most	O
economically	O
priced	O
computer	O
in	O
the	O
European	O
market	O
.	O
</s>
<s>
With	O
the	O
success	O
of	O
Sirius	B-Device
,	O
the	O
team	O
turned	O
its	O
attention	O
to	O
a	O
much	O
larger	O
design	O
.	O
</s>
<s>
Pollard	O
decided	O
that	O
such	O
a	O
machine	O
would	O
be	O
a	O
strong	O
counterpart	O
to	O
the	O
high-end	O
Atlas	B-Device
,	O
and	O
would	O
form	O
the	O
basis	O
for	O
Ferranti	O
's	O
sales	O
for	O
the	O
next	O
five	O
years	O
.	O
</s>
<s>
Several	O
members	O
from	O
Bracknell	O
approached	O
Gordon	O
Scarrott	O
and	O
tried	O
to	O
convince	O
him	O
that	O
Orion	O
should	O
be	O
developed	O
using	O
a	O
conventional	O
all-transistor	O
design	O
.	O
</s>
<s>
They	O
recommended	O
using	O
the	O
"	O
Griblons	O
"	O
circuits	O
developed	O
by	O
Maurice	O
Gribble	O
at	O
Ferranti	O
's	O
Wythenshawe	O
plant	O
,	O
which	O
they	O
had	O
used	O
to	O
successfully	O
implement	O
their	O
Argus	B-Device
computer	O
for	O
the	O
Bristol	O
Bloodhound	O
missile	O
system	O
.	O
</s>
<s>
In	O
September	O
1961	O
Prudential	O
was	O
threatening	O
to	O
cancel	O
their	O
order	O
,	O
and	O
by	O
chance	O
,	O
Braunholtz	O
at	O
that	O
moment	O
sent	O
a	O
telegram	B-Application
to	O
Hall	O
expressing	O
his	O
continuing	O
concerns	O
.	O
</s>
<s>
By	O
the	O
end	O
of	O
October	O
the	O
basic	O
design	O
was	O
complete	O
,	O
and	O
the	O
team	O
started	O
looking	O
for	O
a	O
transistor	B-Application
logic	O
design	O
to	O
use	O
for	O
implementation	O
.	O
</s>
<s>
Although	O
Braunholtz	O
had	O
suggested	O
using	O
the	O
Griblons	O
,	O
the	O
Bracknell	O
group	O
also	O
invited	O
a	O
team	O
of	O
engineers	O
from	O
Ferranti	O
Canada	O
to	O
discuss	O
their	O
recent	O
successes	O
with	O
their	O
"	O
Gemini	O
"	O
design	O
,	O
which	O
was	O
used	O
in	O
their	O
ReserVec	B-Device
system	O
.	O
</s>
<s>
ICT	O
chose	O
to	O
move	O
forward	O
with	O
the	O
FP-6000	O
with	O
minor	O
modifications	O
,	O
and	O
used	O
it	O
as	O
the	O
basis	O
for	O
their	O
ICT	B-Device
1900	I-Device
series	I-Device
through	O
the	O
1960s	O
.	O
</s>
<s>
The	O
basic	O
Orion	O
machine	O
included	O
4,096	O
48-bit	O
words	O
of	O
slow	O
,	O
12μs	O
,	O
core	B-General_Concept
memory	I-General_Concept
,	O
which	O
could	O
be	O
expanded	O
to	O
16,384	O
words	O
.	O
</s>
<s>
The	O
core	B-General_Concept
memory	I-General_Concept
was	O
backed	O
by	O
one	O
or	O
two	O
magnetic	B-General_Concept
drums	I-General_Concept
with	O
16k	O
words	O
each	O
.	O
</s>
<s>
Various	O
offline	O
input/output	B-General_Concept
included	O
magnetic	B-Architecture
disks	I-Architecture
,	O
tape	O
drives	O
,	O
punched	B-Architecture
cards	I-Architecture
,	O
punched	O
tape	O
and	O
printers	O
.	O
</s>
<s>
Most	O
of	O
the	O
Orion	O
's	O
instruction	B-General_Concept
set	I-General_Concept
used	O
a	O
three-address	O
form	O
,	O
with	O
sixty-four	O
48-bit	O
accumulators	O
.	O
</s>
<s>
A	O
key	O
feature	O
of	O
the	O
Orion	O
system	O
was	O
its	O
built-in	O
support	O
for	O
time-sharing	B-General_Concept
.	O
</s>
<s>
This	O
was	O
supported	O
by	O
a	O
series	O
of	O
input/output	B-General_Concept
(	O
I/O	B-General_Concept
)	O
interrupts	O
,	O
or	O
what	O
they	O
referred	O
to	O
as	O
"	O
lockouts	O
"	O
.	O
</s>
<s>
The	O
system	O
automatically	O
switched	O
programs	O
during	O
the	O
time	O
spent	O
waiting	O
for	O
the	O
end	O
of	O
an	O
I/O	B-General_Concept
operation	I-General_Concept
.	O
</s>
<s>
The	O
Orion	O
also	O
supported	O
protected	B-General_Concept
memory	I-General_Concept
in	O
the	O
form	O
of	O
pre-arranged	O
"	O
reservations	O
"	O
.	O
</s>
<s>
The	O
Orion	O
was	O
one	O
of	O
the	O
earliest	O
machines	O
to	O
directly	O
support	O
time-sharing	B-General_Concept
in	O
hardware	O
in	O
spite	O
of	O
intense	O
industry	O
interest	O
;	O
other	O
time-sharing	B-General_Concept
systems	I-General_Concept
of	O
the	O
same	O
era	O
include	O
LEO	B-Device
III	I-Device
of	O
1961	O
,	O
PLATO	B-Operating_System
in	O
early	O
1961	O
,	O
CTSS	B-Operating_System
later	O
that	O
year	O
,	O
and	O
the	O
English	B-Device
Electric	I-Device
KDF9	I-Device
and	O
FP-6000	O
of	O
1964	O
.	O
</s>
<s>
Nebula	O
was	O
created	O
because	O
of	O
Ferranti	O
's	O
perception	O
that	O
the	O
COBOL	B-Application
standard	O
of	O
1960	O
was	O
not	O
sufficiently	O
powerful	O
for	O
their	O
machines	O
,	O
notably	O
as	O
COBOL	B-Application
was	O
developed	O
in	O
the	O
context	O
of	O
decimal	O
,	O
character-oriented	O
batch	B-General_Concept
processing	I-General_Concept
,	O
while	O
Orion	O
was	O
a	O
binary	O
word-oriented	O
multiprogramming	O
system	O
.	O
</s>
<s>
NEBULA	O
adapted	O
many	O
of	O
COBOL	B-Application
's	O
basic	O
concepts	O
,	O
adding	O
new	O
ones	O
of	O
their	O
own	O
.	O
</s>
<s>
NEBULA	O
was	O
later	O
ported	O
to	O
the	O
Atlas	B-Device
as	O
well	O
.	O
</s>
