<s>
TSS/8	B-Operating_System
is	O
a	O
discontinued	O
time-sharing	B-General_Concept
operating	I-General_Concept
system	I-General_Concept
co-written	O
by	O
Don	O
Witcraft	O
and	O
John	O
Everett	O
at	O
Digital	O
Equipment	O
Corporation	O
in	O
1967	O
.	O
</s>
<s>
The	O
operating	B-General_Concept
system	I-General_Concept
runs	O
on	O
the	O
12-bit	B-Device
PDP-8	B-Device
computer	O
and	O
was	O
released	O
in	O
1968	O
.	O
</s>
<s>
TSS/8	B-Operating_System
was	O
designed	O
at	O
Carnegie	O
Mellon	O
University	O
with	O
graduate	O
student	O
Adrian	O
van	O
de	O
Goor	O
,	O
in	O
reaction	O
to	O
the	O
cost	O
,	O
performance	O
,	O
reliability	O
,	O
and	O
complexity	O
of	O
IBM	O
's	O
TSS/360	B-Application
(	O
for	O
their	O
Model	O
67	O
)	O
.	O
</s>
<s>
Don	O
Witcraft	O
wrote	O
the	O
TSS/8	B-Operating_System
scheduler	O
,	O
command	O
decoder	O
and	O
UUO	O
(	O
Unimplemented	O
User	O
Operations	O
)	O
handler	O
.	O
</s>
<s>
John	O
Everett	O
wrote	O
the	O
disk	O
handler	O
,	O
file	O
system	O
,	O
TTY	O
(	O
teletypewriter	O
)	O
handler	O
and	O
680-I	O
service	O
routine	O
for	O
TSS/8	B-Operating_System
.	O
</s>
<s>
Roger	O
Pyle	O
and	O
John	O
Everett	O
wrote	O
the	O
PDP-8	B-Device
Disk	O
Monitor	O
System	O
,	O
and	O
John	O
Everett	O
adapted	O
PAL-III	B-Device
to	O
make	O
PAL-D	B-Device
for	O
DMS	O
.	O
</s>
<s>
Bob	O
Bowering	O
,	O
author	O
of	O
MACRO	O
for	O
the	O
PDP-6	B-Device
and	O
PDP-10	B-Device
,	O
wrote	O
an	O
expanded	O
version	O
,	O
PAL-X	O
,	O
for	O
TSS/8	B-Operating_System
.	O
</s>
<s>
This	O
timesharing	B-General_Concept
system	O
is	O
based	O
on	O
a	O
protection	O
architecture	O
proposed	O
by	O
Adrian	O
Van	O
Der	O
Goor	O
,	O
a	O
grad	O
student	O
of	O
Gordon	O
Bell	O
's	O
at	O
Carnegie-Mellon	O
.	O
</s>
<s>
Each	O
user	O
gets	O
a	O
virtual	O
4K	O
PDP-8	B-Device
;	O
many	O
of	O
the	O
utilities	O
users	O
run	O
on	O
these	O
virtual	O
machines	O
are	O
modified	O
versions	O
of	O
utilities	O
from	O
the	O
Disk	O
Monitor	O
System	O
or	O
paper-tape	O
environments	O
.	O
</s>
<s>
Internally	O
,	O
TSS/8	B-Operating_System
consists	O
of	O
RMON	O
,	O
the	O
resident	B-Application
monitor	I-Application
,	O
DMON	O
,	O
the	O
disk	O
monitor	O
(	O
file	O
system	O
)	O
,	O
and	O
KMON	O
,	O
the	O
keyboard	O
monitor	O
(	O
command	O
shell	O
)	O
.	O
</s>
<s>
BASIC	B-Language
is	O
well	O
supported	O
,	O
while	O
restricted	O
(	O
4K	O
)	O
versions	O
of	O
FORTRAN	B-Application
D	I-Application
and	O
Algol	B-Language
are	O
available	O
.	O
</s>
<s>
FORTRAN-D	O
can	O
only	O
access	O
2	O
data	O
files	O
at	O
a	O
time	O
,	O
and	O
the	O
entire	O
program	O
is	O
MAIN	O
:	O
no	O
subroutines	O
.	O
</s>
<s>
BASIC-8	B-Language
programs	O
are	O
limited	O
to	O
350	O
lines	O
,	O
but	O
"	O
chaining	O
"	O
allows	O
"	O
programs	O
of	O
virtually	O
any	O
length.	O
"	O
</s>
<s>
BASIC-8	B-Language
is	O
based	O
on	O
Dartmouth	B-Language
BASIC	I-Language
but	O
lacks	O
matrix	O
operations	O
,	O
implicit	O
declaration	O
of	O
small	O
arrays	O
,	O
strings	O
,	O
ON-GOTO/GOSUB	O
,	O
TAB	O
,	O
and	O
multiline	O
DEF	O
FN	O
statements	O
.	O
</s>
<s>
PAL-D	B-Device
(	O
Program	O
Assembly	O
Language/Disk	O
)	O
allows	O
the	O
"	O
full	O
standard	O
"	O
but	O
,	O
like	O
all	O
TSS/8	B-Operating_System
programs	O
,	O
is	O
restricted	O
to	O
4K	O
.	O
</s>
<s>
ALGOL	B-Language
is	O
implemented	O
as	O
a	O
known	O
standard	O
subset	O
,	O
"	O
IFIP	O
Subset	O
ALGOL	B-Language
60.	O
"	O
</s>
<s>
It	O
also	O
supports	O
DEC	O
's	O
FOCAL	B-Language
,	O
which	O
was	O
developed	O
specifically	O
for	O
the	O
PDP	O
8/E	O
and	O
it	O
provides	O
an	O
algebraic	O
language	O
as	O
well	O
as	O
a	O
desk	O
calculator	O
mode	O
.	O
</s>
<s>
TSS/8	B-Operating_System
sold	O
more	O
than	O
100	O
copies	O
.	O
</s>
<s>
Operating	O
costs	O
were	O
about	O
1/20	O
of	O
TSS/360	B-Application
.	O
</s>
<s>
TSS/8	B-Operating_System
is	O
also	O
designed	O
to	O
be	O
more	O
cost-effective	O
than	O
the	O
PDP-10	B-Device
"	O
for	O
jobs	O
with	O
low	O
computational	O
requirements	O
(	O
like	O
editing	O
)	O
"	O
.	O
</s>
<s>
The	O
RSTS-11	B-Operating_System
operating	B-General_Concept
system	I-General_Concept
is	O
a	O
descendant	O
of	O
TSS/8	B-Operating_System
.	O
</s>
