<s>
Real-time	B-Operating_System
Multitasking	O
eXecutive	O
(	O
iRMX	B-Operating_System
)	O
is	O
a	O
real-time	B-Operating_System
operating	I-Operating_System
system	I-Operating_System
designed	O
for	O
use	O
with	O
the	O
Intel	B-General_Concept
8080	I-General_Concept
and	O
8086	B-General_Concept
family	O
of	O
processors	O
.	O
</s>
<s>
Intel	O
developed	O
iRMX	B-Operating_System
in	O
the	O
1970s	O
and	O
originally	O
released	O
RMX/80	O
in	O
1976	O
and	O
RMX/86	O
in	O
1980	O
to	O
support	O
and	O
create	O
demand	O
for	O
their	O
processors	O
and	O
Multibus	B-Protocol
system	O
platforms	O
.	O
</s>
<s>
The	O
functional	O
specification	O
for	O
RMX/86	O
was	O
authored	O
by	O
Bruce	O
Schafer	O
and	O
Miles	O
Lewitt	O
and	O
was	O
completed	O
in	O
the	O
summer	O
of	O
1978	O
soon	O
after	O
Intel	O
relocated	O
the	O
entire	O
Multibus	B-Protocol
business	O
from	O
Santa	O
Clara	O
,	O
California	O
to	O
Aloha	O
,	O
Oregon	O
.	O
</s>
<s>
Schafer	O
and	O
Lewitt	O
went	O
on	O
each	O
manage	O
one	O
of	O
the	O
two	O
teams	O
that	O
developed	O
the	O
RMX/86	O
product	O
for	O
release	O
on	O
schedule	O
in	O
1980	O
.	O
</s>
<s>
Effective	O
2000	O
iRMX	B-Operating_System
is	O
supported	O
,	O
maintained	O
,	O
and	O
licensed	O
worldwide	O
by	O
TenAsys	O
Corporation	O
,	O
under	O
an	O
exclusive	O
licensing	O
arrangement	O
with	O
Intel	O
.	O
</s>
<s>
iRMX	B-Operating_System
is	O
a	O
layered	O
design	O
:	O
containing	O
a	O
kernel	O
,	O
nucleus	O
,	O
basic	O
i/o	O
system	O
,	O
extended	O
i/o	O
system	O
and	O
human	O
interface	O
.	O
</s>
<s>
An	O
installation	O
need	O
include	O
only	O
the	O
components	O
required	O
:	O
intertask	O
synchronization	O
,	O
communication	O
subsystems	O
,	O
a	O
filesystem	O
,	O
extended	O
memory	O
management	O
,	O
command	B-Application
shell	O
,	O
etc	O
.	O
</s>
<s>
The	O
native	O
filesystem	O
is	O
specific	O
to	O
iRMX	B-Operating_System
,	O
but	O
has	O
many	O
similarities	O
to	O
the	O
original	O
Unix	B-Application
(	O
V6	O
)	O
filesystem	O
,	O
such	O
as	O
14	O
character	O
path	B-Application
name	I-Application
components	O
,	O
file	O
nodes	O
,	O
sector	O
lists	O
,	O
application	O
readable	O
directories	O
,	O
etc	O
.	O
</s>
<s>
iRMX	B-Operating_System
supports	O
multiple	O
processes	O
(	O
known	O
as	O
jobs	O
in	O
RMX	B-Operating_System
parlance	O
)	O
and	O
multiple	O
threads	B-Operating_System
are	O
supported	O
within	O
each	O
process	O
(	O
task	O
)	O
.	O
</s>
<s>
In	O
addition	O
,	O
interrupt	O
handlers	O
and	O
threads	B-Operating_System
exist	O
to	O
run	O
in	O
response	O
to	O
hardware	O
interrupts	O
.	O
</s>
<s>
Thus	O
,	O
iRMX	B-Operating_System
is	O
a	O
multi-processing	B-Operating_System
,	O
multi-threaded	B-Operating_System
,	O
pre-emptive	O
,	O
real-time	B-Operating_System
operating	I-Operating_System
system	I-Operating_System
(	O
RTOS	B-Operating_System
)	O
.	O
</s>
<s>
The	O
following	O
list	O
of	O
commands	O
are	O
supported	O
by	O
iRMX	B-Operating_System
86	I-Operating_System
.	O
</s>
<s>
iRMX	B-Operating_System
III	O
on	O
Intel	O
Multibus	B-Protocol
hardware	O
is	O
used	O
in	O
the	O
majority	O
core	O
systems	O
on	O
CLSCS	O
the	O
London	O
Underground	O
Central	O
line	O
signals	O
control	O
system	O
was	O
supplied	O
by	O
Westinghouse	O
(	O
now	O
Invensys	O
)	O
and	O
commissioned	O
in	O
the	O
late	O
1990s	O
.	O
</s>
<s>
Automatic	O
train	O
protection	O
is	O
by	O
trackside	O
and	O
train	O
borne	O
equipment	O
that	O
does	O
not	O
use	O
iRMX	B-Operating_System
.	O
</s>
<s>
It	O
is	O
the	O
automatic	O
train	O
supervision	O
elements	O
that	O
use	O
a	O
mix	O
of	O
iRMX	B-Operating_System
on	O
Multibus	B-Protocol
,	O
and	O
Solaris	B-Application
on	O
SPARC	B-Architecture
computers	O
.	O
</s>
<s>
16	O
iRMX	B-Operating_System
local	O
site	O
computers	O
are	O
distributed	O
along	O
the	O
Central	O
line	O
together	O
with	O
6	O
central	O
iRMX	B-Operating_System
computers	O
at	O
the	O
control	O
centre	O
.	O
</s>
<s>
All	O
22	O
iRMX	B-Operating_System
computers	O
are	O
dual	O
redundant	O
.	O
</s>
<s>
iRMX	B-Operating_System
CLSCS	O
continues	O
in	O
full	O
operation	O
.	O
</s>
<s>
Oslo	O
Metro	O
uses	O
a	O
similar	O
,	O
although	O
less	O
complex	O
,	O
Westinghouse-supplied	O
iRMX	B-Operating_System
control	O
system	O
through	O
the	O
central	O
Common	O
Tunnel	O
tracks	O
.	O
</s>
<s>
Several	O
variations	O
of	O
iRMX	B-Operating_System
have	O
been	O
developed	O
since	O
its	O
original	O
introduction	O
on	O
the	O
Intel	B-General_Concept
8080	I-General_Concept
:	O
iRMX	B-Operating_System
I	O
,	O
II	O
and	O
III	O
,	O
iRMX-86	O
,	O
iRMX-286	O
,	O
DOS-RMX	O
,	O
iRMX	B-Operating_System
for	O
Windows	O
,	O
and	O
,	O
most	O
recently	O
,	O
INtime	B-Operating_System
.	O
</s>
<s>
While	O
many	O
of	O
the	O
original	O
variants	O
of	O
iRMX	B-Operating_System
are	O
still	O
in	O
use	O
,	O
only	O
iRMX	B-Operating_System
III	O
,	O
iRMX	B-Operating_System
for	O
Windows	O
,	O
and	O
INtime	B-Operating_System
are	O
currently	O
supported	O
for	O
the	O
development	O
of	O
new	O
real-time	B-Operating_System
applications	O
.	O
</s>
<s>
Each	O
of	O
these	O
three	O
supported	O
variants	O
of	O
iRMX	B-Operating_System
require	O
an	O
Intel	B-General_Concept
80386	I-General_Concept
equivalent	O
or	O
higher	O
processor	O
to	O
run	O
.	O
</s>
<s>
A	O
significant	O
architectural	O
difference	O
between	O
the	O
INtime	B-Operating_System
RTOS	B-Operating_System
and	O
all	O
other	O
iRMX	B-Operating_System
variants	O
is	O
the	O
support	O
for	O
address	O
segments	O
(	O
see	O
x86	B-Device
memory	I-Device
segmentation	I-Device
)	O
.	O
</s>
<s>
The	O
original	O
8086	B-General_Concept
family	O
of	O
processors	O
relied	O
heavily	O
on	O
segment	B-Device
registers	I-Device
to	O
overcome	O
limitations	O
associated	O
with	O
addressing	O
large	O
amounts	O
of	O
memory	O
via	O
16-bit	O
registers	O
.	O
</s>
<s>
The	O
iRMX	B-Operating_System
operating	O
system	O
and	O
the	O
compilers	O
developed	O
for	O
iRMX	B-Operating_System
include	O
features	O
to	O
exploit	O
the	O
segmented	O
addressing	O
features	O
of	O
the	O
original	O
x86	B-Operating_System
architecture	I-Operating_System
.	O
</s>
<s>
The	O
INtime	B-Operating_System
variant	O
of	O
iRMX	B-Operating_System
does	O
not	O
include	O
explicit	O
support	O
for	O
segmentation	O
,	O
opting	O
instead	O
to	O
support	O
only	O
the	O
simpler	O
and	O
more	O
common	O
32-bit	O
flat	O
addressing	O
scheme	O
.	O
</s>
<s>
Despite	O
the	O
fact	O
that	O
native	O
processes	O
written	O
for	O
INtime	B-Operating_System
can	O
only	O
operate	O
using	O
unsegmented	O
flat-mode	O
addressing	O
,	O
it	O
is	O
possible	O
to	O
port	O
and	O
run	O
some	O
older	O
iRMX	B-Operating_System
applications	O
that	O
use	O
segmented	O
addressing	O
to	O
the	O
INtime	B-Operating_System
kernel	O
.	O
</s>
<s>
When	O
Intel	O
introduced	O
the	O
Intel	B-General_Concept
80386	I-General_Concept
processor	O
,	O
in	O
addition	O
to	O
expanding	O
the	O
iRMX	B-Operating_System
RTOS	B-Operating_System
to	O
support	O
32-bit	O
registers	O
,	O
iRMX	B-Operating_System
III	O
also	O
included	O
support	O
for	O
the	O
four	O
distinct	O
protection	O
rings	O
(	O
named	O
rings	O
0	O
through	O
3	O
)	O
which	O
describe	O
the	O
protected-mode	B-Application
mechanism	O
of	O
the	O
Intel	O
32-bit	O
architecture	O
.	O
</s>
<s>
The	O
I	O
,	O
II	O
,	O
III	O
,	O
-286	O
and	O
-86	O
variants	O
are	O
intended	O
as	O
standalone	O
real-time	B-Operating_System
operating	I-Operating_System
systems	I-Operating_System
.	O
</s>
<s>
A	O
number	O
of	O
development	O
utilities	O
and	O
applications	O
were	O
made	O
for	O
iRMX	B-Operating_System
,	O
such	O
as	O
compilers	O
(	O
PL/M	B-Language
,	O
Fortran	B-Application
,	O
C	B-Language
)	O
,	O
an	O
editor	O
(	O
Aedit	O
)	O
,	O
process	O
and	O
data	O
acquisition	O
applications	O
and	O
so	O
on	O
.	O
</s>
<s>
Cross	O
compilers	O
hosted	O
on	O
the	O
VAX/VMS	B-Operating_System
system	O
were	O
also	O
made	O
available	O
by	O
Intel	O
.	O
</s>
<s>
iRMX	B-Operating_System
III	O
is	O
still	O
supported	O
today	O
and	O
has	O
been	O
used	O
as	O
the	O
core	O
technology	O
for	O
newer	O
real-time	B-Operating_System
virtualization	O
RTOS	B-Operating_System
products	O
including	O
iRMX	B-Operating_System
for	O
Windows	O
and	O
INtime	B-Operating_System
.	O
</s>
<s>
DOS-RMX	O
is	O
a	O
variant	O
of	O
the	O
standalone	O
iRMX	B-Operating_System
operating	O
system	O
designed	O
to	O
allow	O
two	O
operating	O
systems	O
to	O
share	O
a	O
single	O
hardware	O
platform	O
.	O
</s>
<s>
In	O
simplest	O
terms	O
,	O
DOS	B-Device
and	O
iRMX	B-Operating_System
operate	O
concurrently	O
on	O
a	O
single	O
IBM	O
PC	O
compatible	O
computer	O
,	O
where	O
iRMX	B-Operating_System
tasks	O
(	O
processes	O
)	O
have	O
scheduling	O
priority	O
over	O
the	O
DOS	B-Device
kernel	O
,	O
interrupts	O
,	O
and	O
applications	O
.	O
</s>
<s>
iRMX	B-Operating_System
events	O
(	O
e.g.	O
,	O
hardware	O
interrupts	O
)	O
pre-empt	O
the	O
DOS	B-Device
kernel	O
to	O
ensure	O
that	O
tasks	O
can	O
respond	O
to	O
real-time	B-Operating_System
events	O
in	O
a	O
time-deterministic	O
manner	O
.	O
</s>
<s>
In	O
a	O
functional	O
sense	O
,	O
DOS-RMX	O
is	O
the	O
predecessor	O
to	O
iRMX	B-Operating_System
for	O
Windows	O
and	O
INtime	B-Operating_System
.	O
</s>
<s>
In	O
practice	O
,	O
DOS-RMX	O
appears	O
as	O
a	O
Terminate-and-stay-resident	O
(	O
TSR	O
)	O
program	O
to	O
the	O
DOS	B-Device
kernel	O
.	O
</s>
<s>
Once	O
loaded	O
as	O
a	O
TSR	O
,	O
iRMX	B-Operating_System
takes	O
over	O
the	O
CPU	O
,	O
changing	O
to	O
protected	B-Application
mode	I-Application
and	O
running	O
DOS	B-Device
in	O
a	O
virtual	B-Architecture
machine	I-Architecture
within	O
an	O
RMX	B-Operating_System
task	O
.	O
</s>
<s>
This	O
combination	O
provides	O
RMX	B-Operating_System
real-time	B-Operating_System
functionality	O
as	O
well	O
as	O
full	O
DOS	B-Device
services	O
.	O
</s>
<s>
Like	O
DOS-RMX	O
,	O
this	O
system	O
provides	O
a	O
hybrid	O
mixture	O
of	O
services	O
and	O
capabilities	O
defined	O
by	O
DOS	B-Device
,	O
Windows	O
,	O
and	O
iRMX	B-Operating_System
.	O
</s>
<s>
Inter-application	O
communication	O
via	O
an	O
enhanced	O
Windows	O
DDE	B-Operating_System
capability	O
allows	O
RMX	B-Operating_System
tasks	O
to	O
communicate	O
with	O
Windows	O
processes	O
.	O
</s>
<s>
iRMX	B-Operating_System
for	O
Windows	O
was	O
originally	O
intended	O
for	O
use	O
in	O
combination	O
with	O
the	O
16-bit	O
version	O
of	O
Windows	O
.	O
</s>
<s>
In	O
2002	O
iRMX	B-Operating_System
for	O
Windows	O
was	O
reintroduced	O
by	O
adding	O
these	O
RMX	B-Operating_System
personalities	O
to	O
the	O
INtime	B-Operating_System
RTOS	B-Operating_System
for	O
Windows	O
,	O
allowing	O
it	O
to	O
be	O
used	O
in	O
conjunction	O
with	O
the	O
32-bit	O
protected-mode	B-Application
versions	O
of	O
Windows	O
(	O
Windows	B-Device
NT	I-Device
,	O
Windows	O
2000	O
,	O
etc	O
.	O
</s>
<s>
Like	O
its	O
iRMX	B-Operating_System
predecessors	O
,	O
INtime	B-Operating_System
is	O
a	O
real-time	B-Operating_System
operating	I-Operating_System
system	I-Operating_System
.	O
</s>
<s>
And	O
,	O
like	O
DOS-RMX	O
and	O
iRMX	B-Operating_System
for	O
Windows	O
,	O
it	O
runs	O
concurrently	O
with	O
a	O
general-purpose	O
operating	O
system	O
on	O
a	O
single	O
hardware	O
platform	O
.	O
</s>
<s>
INtime	B-Operating_System
1.0	O
was	O
originally	O
introduced	O
in	O
1997	O
in	O
conjunction	O
with	O
the	O
Windows	B-Device
NT	I-Device
operating	O
system	O
.	O
</s>
<s>
Since	O
then	O
it	O
has	O
been	O
upgraded	O
to	O
include	O
support	O
for	O
all	O
subsequent	O
protected-mode	B-Application
Microsoft	O
Windows	O
platforms	O
,	O
including	O
Windows	O
Vista	O
and	O
Windows	O
7	O
.	O
</s>
<s>
INtime	B-Operating_System
can	O
also	O
be	O
used	O
as	O
a	O
stand-alone	O
RTOS	B-Operating_System
.	O
</s>
<s>
INtime	B-Operating_System
binaries	O
are	O
able	O
to	O
run	O
unchanged	O
when	O
running	O
on	O
a	O
stand-alone	O
node	O
of	O
the	O
INtime	B-Operating_System
RTOS	B-Operating_System
.	O
</s>
<s>
Unlike	O
Windows	O
,	O
INtime	B-Operating_System
can	O
run	O
on	O
an	O
Intel	B-General_Concept
80386	I-General_Concept
or	O
equivalent	O
processor	O
.	O
</s>
<s>
The	O
introduction	O
of	O
INtime	B-Operating_System
3.0	O
included	O
several	O
important	O
enhancements	O
.	O
</s>
<s>
Among	O
them	O
,	O
support	O
for	O
multi-core	O
processors	O
and	O
the	O
ability	O
to	O
debug	B-Device
real-time	B-Operating_System
processes	O
on	O
the	O
INtime	B-Operating_System
kernel	O
using	O
Microsoft	B-Application
Visual	I-Application
Studio	I-Application
.	O
</s>
<s>
INtime	B-Operating_System
is	O
not	O
an	O
SMP	B-Operating_System
operating	O
system	O
,	O
thus	O
support	O
for	O
multi-core	O
processors	O
is	O
restricted	O
to	O
a	O
special	O
form	O
of	O
asymmetric	B-Operating_System
multiprocessing	I-Operating_System
.	O
</s>
<s>
When	O
used	O
on	O
a	O
multi-core	O
processor	O
INtime	B-Operating_System
can	O
be	O
configured	O
to	O
run	O
on	O
one	O
CPU	O
core	O
while	O
Windows	O
runs	O
on	O
the	O
remaining	O
processor	O
core(s )	O
.	O
</s>
