<s>
MIL-STD-1750A	B-General_Concept
or	O
1750A	B-General_Concept
is	O
the	O
formal	O
definition	O
of	O
a	O
16-bit	O
computer	O
instruction	B-General_Concept
set	I-General_Concept
architecture	I-General_Concept
(	O
ISA	O
)	O
,	O
including	O
both	O
required	O
and	O
optional	O
components	O
,	O
as	O
described	O
by	O
the	O
military	O
standard	O
document	O
MIL-STD-1750A	B-General_Concept
(	O
1980	O
)	O
.	O
</s>
<s>
In	O
addition	O
to	O
the	O
core	O
ISA	O
,	O
the	O
definition	O
defines	O
optional	O
instructions	O
,	O
such	O
as	O
a	O
FPU	B-General_Concept
and	O
MMU	B-General_Concept
.	O
</s>
<s>
Importantly	O
,	O
the	O
standard	O
does	O
not	O
define	O
the	O
implementation	O
details	O
of	O
a	O
1750A	B-General_Concept
processor	O
.	O
</s>
<s>
The	O
1750A	B-General_Concept
supports	O
216	O
16-bit	O
words	O
of	O
memory	O
for	O
the	O
core	O
standard	O
.	O
</s>
<s>
The	O
standard	O
defines	O
an	O
optional	O
memory	B-General_Concept
management	I-General_Concept
unit	I-General_Concept
that	O
allows	O
220	O
16-bit	O
words	O
of	O
memory	O
using	O
512	O
page	O
mapping	O
registers	O
(	O
in	O
the	O
I/O	O
space	O
)	O
,	O
defining	O
separate	O
instruction	O
and	O
data	O
spaces	O
,	O
and	O
keyed	O
memory	O
access	O
control	O
.	O
</s>
<s>
Registers	O
1	O
through	O
15	O
can	O
be	O
used	O
as	O
index	B-General_Concept
registers	I-General_Concept
.	O
</s>
<s>
Any	O
of	O
the	O
16	O
registers	O
can	O
be	O
used	O
as	O
a	O
stack	B-Application
pointer	O
for	O
the	O
SJS	O
and	O
URS	O
instructions	O
(	O
stack	B-Application
jump	O
subroutine	O
and	O
unstack	O
return	O
subroutine	O
)	O
,	O
but	O
only	O
register	O
15	O
is	O
used	O
as	O
the	O
stack	B-Application
pointer	O
for	O
the	O
PSHM	O
and	O
POPM	O
instructions	O
(	O
push	O
multiple	O
and	O
pop	O
multiple	O
)	O
.	O
</s>
<s>
The	O
computer	O
has	O
instructions	O
for	O
16	O
,	O
and	O
32-bit	O
binary	O
arithmetic	O
,	O
as	O
well	O
as	O
32	O
and	O
48	O
bit	O
floating	B-Algorithm
point	I-Algorithm
.	O
</s>
<s>
Because	O
MIL-STD-1750A	B-General_Concept
does	O
not	O
define	O
implementation	O
details	O
,	O
1750A	B-General_Concept
products	O
are	O
available	O
from	O
a	O
wide	O
variety	O
of	O
companies	O
in	O
the	O
form	O
of	O
component	O
,	O
board	O
,	O
and	O
system-level	O
offerings	O
implemented	O
in	O
myriad	O
technologies	O
,	O
often	O
the	O
most	O
advanced	O
and	O
exotic	O
of	O
their	O
respective	O
periods	O
(	O
e.g.	O
</s>
<s>
GaAs	O
,	O
ECL	B-General_Concept
,	O
SoS	B-Algorithm
)	O
.	O
</s>
<s>
1750A	B-General_Concept
systems	O
often	O
offer	O
high	O
levels	O
of	O
protection	O
from	O
radiation	O
and	O
other	O
hazardous	O
environments	O
,	O
making	O
them	O
particularly	O
suited	O
for	O
military	O
,	O
aviation	O
and	O
space	O
applications	O
.	O
</s>
<s>
Examples	O
of	O
MIL-STD-1750A	B-General_Concept
implementations	O
include	O
:	O
</s>
<s>
CPU	O
Technology	O
,	O
Inc	O
.	O
CPU1750A-FB	O
,	O
a	O
high	O
performance	O
1750A	B-General_Concept
SOC	B-Architecture
designed	O
to	O
give	O
existing	O
applications	O
a	O
late	O
life	O
performance	O
boost	O
.	O
</s>
<s>
A	O
radiation	O
hardened	O
SOC	B-Architecture
implementation	O
on	O
a	O
64-pin	O
multichip	O
module	O
with	O
an	O
optional	O
MMU	B-General_Concept
.	O
</s>
<s>
GEC-Plessey	O
RH1750	B-General_Concept
,	O
a	O
radiation-hardened	O
version	O
for	O
aerospace	O
and	O
space	O
flight	O
applications	O
.	O
</s>
<s>
The	O
HX1750	O
includes	O
an	O
FPU	B-General_Concept
and	O
peripherals	O
on	O
chip	O
.	O
</s>
<s>
A	O
multi-board	O
silicon	B-Algorithm
on	I-Algorithm
sapphire	I-Algorithm
implementation	O
specifically	O
designed	O
for	O
space	O
flight	O
.	O
</s>
<s>
Marconi	O
Electronic	O
Devices	O
MIL-STD-1750A	B-General_Concept
.	O
</s>
<s>
A	O
radiation	O
hardened	O
SoS	B-Algorithm
three-die	O
implementation	O
on	O
a	O
64-pin	O
multichip	O
module	O
.	O
</s>
<s>
National	B-Device
Semiconductor	I-Device
PACE	I-Device
P1750A	O
.	O
</s>
<s>
The	O
PACE	O
normally	O
runs	O
a	O
version	O
of	O
the	O
Data	B-Device
General	I-Device
Nova	I-Device
instruction	B-General_Concept
set	I-General_Concept
,	O
but	O
was	O
adapted	O
to	O
run	O
MIL-STD-1750A	B-General_Concept
using	O
new	O
microcode	B-Device
.	O
</s>
<s>
The	O
family	O
includes	O
the	O
P1750A	O
CPU	O
,	O
the	O
P1750AE	O
Enhanced	O
CPU	O
,	O
the	O
P1753	O
Memory	B-General_Concept
Management	I-General_Concept
Unit	I-General_Concept
(	O
MMU	B-General_Concept
)	O
,	O
the	O
P1754	O
Processor	O
Interface	O
Chip	O
(	O
PIC	O
)	O
and	O
the	O
P1757ME	O
Multi-Chip	O
Module	O
.	O
</s>
<s>
Royal	O
Aircraft	O
Establishment	O
Farnborough	O
MIL-STD-1750A	B-General_Concept
implementation	O
in	O
AMD	B-General_Concept
2901	I-General_Concept
bit-slice	B-General_Concept
technology	O
.	O
</s>
<s>
Processors	O
based	O
on	O
MIL-STD-1750A	B-General_Concept
are	O
often	O
programmed	O
in	O
JOVIAL	B-Language
,	O
a	O
high-level	O
programming	O
language	O
defined	O
by	O
the	O
United	O
States	O
Department	O
of	O
Defense	O
which	O
is	O
derived	O
from	O
ALGOL	B-Language
58	I-Language
.	O
</s>
<s>
Later	O
,	O
the	O
Ada	B-Language
was	O
heavily	O
used	O
.	O
</s>
<s>
There	O
are	O
also	O
C	B-Language
compilers	O
,	O
for	O
example	O
Cleanscape	O
XTC-1750A	O
.	O
</s>
<s>
Older	O
versions	O
of	O
GNU	B-Application
GCC	I-Application
contain	O
support	O
for	O
MIL-STD-1750A	B-General_Concept
;	O
it	O
was	O
declared	O
obsolete	O
in	O
version	O
3.1	O
,	O
and	O
removed	O
in	O
subsequent	O
versions	O
.	O
</s>
<s>
In	O
addition	O
,	O
DDC-I	O
provides	O
its	O
SCORE	O
Integrated	O
Development	O
Environment	O
(	O
IDE	O
)	O
with	O
both	O
Ada95	B-Language
and	O
C	B-Language
compilers	O
,	O
and	O
TADS	O
(	O
Tartan	O
Ada	B-Language
Development	O
System	O
)	O
Ada83	B-Language
development	O
environment	O
,	O
both	O
targeting	O
processors	O
based	O
on	O
MIL-STD-1750A	B-General_Concept
.	O
</s>
<s>
The	O
U.S.	O
Air	O
Force	O
defined	O
the	O
standard	O
in	O
order	O
to	O
have	O
a	O
common	O
computing	O
architecture	O
and	O
thereby	O
reduce	O
the	O
costs	O
of	O
software	O
and	O
computer	O
systems	O
for	O
all	O
military	B-Device
computing	I-Device
needs	O
.	O
</s>
<s>
This	O
includes	O
embedded	O
tasks	O
such	O
as	O
aircraft	O
and	O
missile	O
control	O
systems	O
as	O
well	O
as	O
more	O
mundane	O
general	O
military	B-Device
computing	I-Device
needs	O
.	O
</s>
<s>
The	O
advantages	O
of	O
this	O
concept	O
are	O
recognized	O
outside	O
of	O
the	O
USAF	O
,	O
and	O
the	O
1750A	B-General_Concept
has	O
been	O
adopted	O
by	O
other	O
organizations	O
such	O
as	O
the	O
European	O
Space	O
Agency	O
,	O
NASA	O
,	O
Israeli	O
Aircraft	O
Industries	O
,	O
and	O
many	O
projects	O
in	O
academia	O
.	O
</s>
<s>
Examples	O
of	O
military	O
aircraft	O
using	O
the	O
1750A	B-General_Concept
include	O
:	O
</s>
<s>
Fully	O
space-rated	O
implementations	O
make	O
the	O
1750A	B-General_Concept
one	O
of	O
the	O
few	O
types	O
of	O
computers	O
that	O
are	O
applicable	O
for	O
use	O
in	O
deep	O
space	O
applications	O
.	O
</s>
<s>
Example	O
spacecraft	O
that	O
use	O
the	O
1750A	B-General_Concept
are	O
:	O
</s>
<s>
The	O
MIL-STD-1750B	O
was	O
to	O
be	O
a	O
successor	O
architecture	O
to	O
the	O
MIL-STD-1750A	B-General_Concept
,	O
with	O
added	O
and	O
expanded	O
features	O
,	O
some	O
of	O
which	O
were	O
optional	O
.	O
</s>
<s>
However	O
,	O
no	O
finalized	O
specification	O
was	O
ever	O
issued	O
for	O
the	O
1750B	O
,	O
as	O
military	O
and	O
industry	O
attention	O
shifted	O
to	O
32-bit	O
architectural	O
alternatives	O
such	O
as	O
the	O
MIPS	B-Device
R3000	I-Device
.	O
</s>
