<s>
TRIPOS	B-Operating_System
(	O
TRIvial	O
Portable	O
Operating	B-General_Concept
System	I-General_Concept
)	O
is	O
a	O
computer	B-General_Concept
operating	I-General_Concept
system	I-General_Concept
.	O
</s>
<s>
The	O
first	O
version	O
appeared	O
in	O
January	O
1978	O
and	O
it	O
originally	O
ran	O
on	O
a	O
PDP-11	B-Device
.	O
</s>
<s>
Later	O
it	O
was	O
ported	O
to	O
the	O
Computer	O
Automation	O
LSI4	O
and	O
the	O
Data	B-Device
General	I-Device
Nova	I-Device
.	O
</s>
<s>
Work	O
on	O
a	O
Motorola	B-Device
68000	I-Device
version	O
started	O
in	O
1981	O
at	O
the	O
University	O
of	O
Bath	O
.	O
</s>
<s>
MetaComCo	B-Device
acquired	O
the	O
rights	O
to	O
the	O
68000	B-Device
version	O
and	O
continued	O
development	O
until	O
TRIPOS	B-Operating_System
was	O
chosen	O
by	O
Commodore	O
in	O
March	O
1985	O
to	O
form	O
part	O
of	O
an	O
operating	B-General_Concept
system	I-General_Concept
for	O
their	O
new	O
Amiga	B-Device
computer	I-Device
;	O
it	O
was	O
also	O
used	O
at	O
Cambridge	O
as	O
part	O
of	O
the	O
Cambridge	B-Operating_System
Distributed	I-Operating_System
Computing	I-Operating_System
System	I-Operating_System
.	O
</s>
<s>
Students	O
in	O
the	O
Computer	O
Science	O
department	O
at	O
Cambridge	O
affectionately	O
refer	O
to	O
TRIPOS	B-Operating_System
as	O
the	O
Terribly	O
Reliable	O
,	O
Incredibly	O
Portable	O
Operating	B-General_Concept
System	I-General_Concept
.	O
</s>
<s>
The	O
name	O
TRIPOS	B-Operating_System
also	O
refers	O
to	O
the	O
Tripos	B-Operating_System
system	I-Operating_System
of	I-Operating_System
undergraduate	I-Operating_System
courses	I-Operating_System
and	I-Operating_System
examinations	I-Operating_System
,	O
which	O
is	O
unique	O
to	O
Cambridge	O
University	O
.	O
</s>
<s>
In	O
July	O
1985	O
,	O
the	O
Amiga	B-Device
was	O
introduced	O
,	O
incorporating	O
TRIPOS	B-Operating_System
in	O
the	O
AmigaDOS	B-Operating_System
module	O
of	O
AmigaOS	B-Application
.	O
</s>
<s>
AmigaDOS	B-Operating_System
included	O
a	O
command-line	B-Application
interface	I-Application
and	O
the	O
Amiga	B-Application
File	I-Application
System	I-Application
.	O
</s>
<s>
The	O
entire	O
AmigaDOS	B-Operating_System
module	O
was	O
originally	O
written	O
in	O
BCPL	B-Language
(	O
an	O
ancestor	O
of	O
the	O
C	B-Language
programming	I-Language
language	I-Language
)	O
,	O
the	O
same	O
language	O
used	O
to	O
write	O
TRIPOS	B-Operating_System
.	O
</s>
<s>
AmigaDOS	B-Operating_System
would	O
later	O
be	O
rewritten	O
in	O
C	B-Language
from	O
AmigaOS	B-Application
2.x	O
onwards	O
,	O
retaining	O
backwards	O
compatibility	O
with	O
1.x	O
up	O
until	O
AmigaOS	B-Application
4	I-Application
(	O
completely	O
rewritten	O
in	O
C	B-Language
)	O
when	O
AmigaDOS	B-Operating_System
abandoned	O
its	O
BCPL	B-Language
legacy	O
.	O
</s>
<s>
TRIPOS	B-Operating_System
provided	O
features	O
such	O
as	O
pre-emptive	B-Operating_System
multi-tasking	I-Operating_System
(	O
using	O
strict-priority	O
scheduling	O
)	O
,	O
a	O
hierarchical	B-Application
file	I-Application
system	I-Application
and	O
multiple	O
command	B-Application
line	I-Application
interpreters	O
.	O
</s>
<s>
The	O
most	O
important	O
TRIPOS	B-Operating_System
concepts	O
have	O
been	O
the	O
non-memory-management	O
approach	O
(	O
meaning	O
no	O
checks	O
are	O
performed	O
to	O
stop	O
programs	O
from	O
using	O
unallocated	O
memory	O
)	O
and	O
message	O
passing	O
by	O
means	O
of	O
passing	O
pointers	O
instead	O
of	O
copying	O
message	O
contents	O
.	O
</s>
<s>
Those	O
two	O
concepts	O
together	O
allowed	O
for	O
sending	O
and	O
receiving	O
over	O
1250	O
packets	O
per	O
second	O
on	O
a	O
10MHz	O
Motorola	B-Device
68010	I-Device
CPU	O
.	O
</s>
<s>
Most	O
of	O
TRIPOS	B-Operating_System
was	O
implemented	O
in	O
BCPL	B-Language
.	O
</s>
<s>
The	O
kernel	B-Operating_System
and	O
device	B-Application
drivers	I-Application
were	O
implemented	O
in	O
assembly	B-Language
language	I-Language
.	O
</s>
<s>
One	O
notable	O
feature	O
of	O
TRIPOS/BCPL	O
was	O
its	O
cultural	O
use	O
of	O
shared	O
libraries	O
,	O
untypical	O
at	O
the	O
time	O
,	O
resulting	O
in	O
small	O
and	O
therefore	O
fast	O
loading	O
utilities	O
.	O
</s>
<s>
For	O
example	O
,	O
many	O
of	O
the	O
standard	O
system	O
utilities	O
were	O
well	O
below	O
0.5	O
Kbytes	O
in	O
size	O
,	O
compared	O
to	O
a	O
typical	O
minimum	O
of	O
about	O
20	O
Kbytes	O
for	O
functionally	O
equivalent	O
code	O
on	O
a	O
modern	O
Unix	O
or	O
Linux	B-Application
.	O
</s>
<s>
TRIPOS	B-Operating_System
was	O
ported	O
to	O
a	O
number	O
of	O
machines	O
,	O
including	O
the	O
Data	B-Device
General	I-Device
Nova	I-Device
2	I-Device
,	O
the	O
Computer	O
Automation	O
LSI4	O
,	O
Motorola	B-Device
68000	I-Device
and	O
Intel	B-General_Concept
8086	I-General_Concept
-	O
based	O
hardware	O
.	O
</s>
<s>
It	O
included	O
support	O
for	O
the	O
Cambridge	B-General_Concept
Ring	I-General_Concept
local	B-General_Concept
area	I-General_Concept
network	I-General_Concept
.	O
</s>
<s>
More	O
recently	O
,	O
Martin	O
Richards	O
produced	O
a	O
port	O
of	O
TRIPOS	B-Operating_System
to	O
run	O
under	O
Linux	B-Application
,	O
using	O
Cintcode	O
BCPL	B-Language
virtual	B-Architecture
machine	I-Architecture
.	O
</s>
<s>
As	O
of	O
February	O
2020	O
,	O
TRIPOS	B-Operating_System
is	O
still	O
actively	O
maintained	O
by	O
Open	O
G	O
I	O
Ltd	O
.	O
(	O
formerly	O
Misys	O
Financial	O
Systems	O
)	O
in	O
Worcestershire	O
,	O
UK	O
.	O
</s>
<s>
Many	O
British	O
insurance	O
brokers	O
have	O
a	O
Linux/Intel	O
based	O
TRIPOS	B-Operating_System
system	O
serving	O
networked	O
workstations	O
over	O
a	O
TCP/IP	B-Protocol
connection	O
-	O
the	O
systems	O
are	O
used	O
to	O
run	O
Open	O
G	O
I	O
's	O
BROOMS	O
Application	O
suite	O
.	O
</s>
<s>
The	O
following	O
list	O
of	O
commands	B-Application
is	O
supported	O
by	O
the	O
TRIPOS	B-Operating_System
CLI	O
.	O
</s>
<s>
Cintpos	B-Operating_System
is	O
an	O
experimental	O
interpretive	O
version	O
of	O
TRIPOS	B-Operating_System
which	O
runs	O
on	O
the	O
Cintcode	O
BCPL	B-Language
virtual	B-Architecture
machine	I-Architecture
,	O
also	O
developed	O
by	O
Martin	O
Richards	O
.	O
</s>
