<s>
It	O
was	O
designed	O
to	O
deliver	O
enormous	O
computational	O
power	O
at	O
lower	O
cost	O
than	O
other	O
existing	O
supercomputer	B-Architecture
architectures	O
,	O
by	O
using	O
thousands	O
of	O
simple	O
processing	O
elements	O
,	O
rather	O
than	O
one	O
or	O
a	O
few	O
highly	O
complex	O
CPUs	B-Device
.	O
</s>
<s>
It	O
was	O
based	O
on	O
Goodyear	O
's	O
earlier	O
STARAN	B-Device
array	O
processor	O
,	O
a	O
4x256	O
1-bit	O
processing	O
element	O
(	O
PE	O
)	O
computer	O
.	O
</s>
<s>
The	O
PEs	O
operated	O
in	O
a	O
single	B-Device
instruction	I-Device
,	I-Device
multiple	I-Device
data	I-Device
(	O
SIMD	B-Device
)	O
fashioneach	O
PE	O
performed	O
the	O
same	O
operation	O
simultaneously	O
,	O
on	O
different	O
data	O
elements	O
,	O
under	O
the	O
control	O
of	O
a	O
microprogrammed	O
control	O
unit	O
.	O
</s>
<s>
It	O
was	O
succeeded	O
at	O
Goddard	O
by	O
the	O
MasPar	B-Device
MP-1	O
and	O
Cray	B-Device
T3D	I-Device
massively	B-Operating_System
parallel	I-Operating_System
computers	I-Operating_System
.	O
</s>
<s>
The	O
MPP	O
was	O
initially	O
developed	O
for	O
high-speed	O
analysis	O
of	O
satellite	B-Application
images	O
.	O
</s>
<s>
40	O
projects	O
were	O
accepted	O
,	O
to	O
form	O
the	O
"	O
MPP	O
Working	O
Group	O
"	O
;	O
results	O
of	O
most	O
of	O
them	O
were	O
presented	O
at	O
the	O
First	O
Symposium	O
on	O
the	O
Frontiers	O
of	O
Massively	B-Operating_System
Parallel	I-Operating_System
Computation	O
,	O
in	O
1986	O
.	O
</s>
<s>
The	O
PEs	O
were	O
implemented	O
on	O
a	O
custom	O
silicon-on-sapphire	B-Algorithm
LSI	O
chip	O
which	O
contained	O
eight	O
of	O
the	O
PEs	O
as	O
a	O
2x4	O
subarray	O
.	O
</s>
<s>
Each	O
of	O
the	O
PEs	O
had	O
arithmetic	O
and	O
logic	O
units	O
,	O
35	O
shift	O
registers	O
,	O
and	O
1024	O
bits	O
of	O
random-access	B-Architecture
memory	I-Architecture
implemented	O
with	O
off-the-shelf	O
memory	O
chips	O
.	O
</s>
<s>
The	O
processors	O
worked	O
in	O
a	O
bit-slice	B-General_Concept
manner	O
and	O
could	O
operate	O
on	O
variable	O
lengths	O
of	O
data	O
.	O
</s>
<s>
The	O
original	O
Host	O
Processor	O
was	O
a	O
PDP-11	B-Device
,	O
which	O
was	O
soon	O
replaced	O
by	O
a	O
VAX-11/780	O
connected	O
to	O
the	O
MPP	O
by	O
a	O
DR-780	O
channel	O
.	O
</s>
<s>
The	O
VAX	O
ran	O
the	O
VMS	B-Operating_System
operating	I-Operating_System
system	I-Operating_System
,	O
and	O
was	O
programmed	O
in	O
MPP	O
Pascal	O
.	O
</s>
