<s>
JOSS	B-Language
(	O
acronym	O
for	O
JOHNNIAC	B-Language
Open	I-Language
Shop	I-Language
System	I-Language
)	O
was	O
one	O
of	O
the	O
first	O
interactive	O
,	O
time-sharing	B-General_Concept
programming	O
languages	O
.	O
</s>
<s>
It	O
pioneered	O
many	O
features	O
that	O
would	O
become	O
common	O
in	O
languages	O
from	O
the	O
1960s	O
into	O
the	O
1980s	O
,	O
including	O
use	O
of	O
line	B-Application
numbers	I-Application
as	O
both	O
editing	O
instructions	O
and	O
targets	O
for	O
branches	B-General_Concept
,	O
statements	O
predicated	O
by	O
boolean	O
decisions	O
,	O
and	O
a	O
built-in	O
source-code	B-Application
editor	I-Application
that	O
can	O
perform	O
instructions	O
in	O
direct	O
or	O
immediate	O
mode	O
,	O
what	O
they	O
termed	O
a	O
conversational	B-General_Concept
user	I-General_Concept
interface	I-General_Concept
.	O
</s>
<s>
JOSS	B-Language
was	O
initially	O
implemented	O
on	O
the	O
JOHNNIAC	B-Device
machine	O
at	O
RAND	O
Corporation	O
and	O
put	O
online	O
in	O
1963	O
.	O
</s>
<s>
JOHNNIAC	B-Device
was	O
retired	O
in	O
1966	O
and	O
replaced	O
by	O
a	O
PDP-6	B-Device
,	O
which	O
ultimately	O
grew	O
to	O
support	O
hundreds	O
of	O
computer	B-General_Concept
terminals	I-General_Concept
based	O
on	O
the	O
IBM	O
Selectric	O
.	O
</s>
<s>
The	O
terminals	O
used	O
green	O
ink	O
for	O
user	B-General_Concept
input	I-General_Concept
and	O
black	O
for	O
the	O
computer	O
's	O
response	O
.	O
</s>
<s>
Any	O
command	B-Application
that	O
was	O
not	O
understood	O
elicited	O
the	O
response	O
or	O
.	O
</s>
<s>
Some	O
remained	O
similar	O
to	O
the	O
original	O
,	O
like	O
TELCOMP	B-Language
and	O
STRINGCOMP	B-Language
,	O
CAL	B-Language
,	O
CITRAN	B-Language
,	O
ISIS	O
,	O
PIL/I	O
,	O
JEAN	B-Language
(	O
ICT	B-Device
1900	I-Device
series	I-Device
)	O
,	O
Algebraic	O
Interpretive	O
Dialogue	O
(	O
AID	O
,	O
on	O
PDP-10	B-Device
)	O
;	O
while	O
others	O
,	O
such	O
as	O
FOCAL	B-Language
and	O
MUMPS	B-Language
,	O
developed	O
in	O
distinctive	O
directions	O
.	O
</s>
<s>
It	O
also	O
bears	O
a	O
strong	O
resemblance	O
to	O
the	O
BASIC	O
interpreters	O
found	O
on	O
microcomputers	B-Architecture
in	O
the	O
1980s	O
,	O
differing	O
mainly	O
in	O
syntax	O
details	O
.	O
</s>
<s>
In	O
1959	O
,	O
Willis	O
Ware	O
wrote	O
a	O
RAND	O
memo	O
on	O
the	O
topic	O
of	O
computing	O
in	O
which	O
he	O
stated	O
future	O
computers	O
would	O
have	O
"	O
a	O
multiplicity	O
of	O
personal	O
input-output	B-General_Concept
stations	O
,	O
so	O
that	O
many	O
people	O
can	O
interact	O
with	O
the	O
machine	O
at	O
the	O
same	O
time.	O
"	O
</s>
<s>
The	O
memo	O
gained	O
the	O
interest	O
of	O
the	O
US	O
Air	O
Force	O
,	O
Rand	O
's	O
primary	O
sponsors	O
,	O
and	O
in	O
1960	O
,	O
they	O
formed	O
the	O
Information	O
Processor	O
Project	O
to	O
explore	O
this	O
concept	O
,	O
what	O
would	O
soon	O
be	O
known	O
as	O
time-sharing	B-General_Concept
.	O
</s>
<s>
The	O
project	O
was	O
not	O
specifically	O
about	O
time-sharing	B-General_Concept
,	O
but	O
aimed	O
to	O
improve	O
human-computer	O
interaction	O
overall	O
.	O
</s>
<s>
As	O
JOSS	B-Language
director	O
Keith	O
Uncapher	O
later	O
put	O
it	O
:	O
</s>
<s>
A	O
formal	O
proposal	O
to	O
develop	O
what	O
became	O
JOSS	B-Language
on	O
the	O
JOHNNIAC	B-Device
computer	O
was	O
accepted	O
in	O
March	O
1961	O
.	O
</s>
<s>
JOSS	B-Language
was	O
implemented	O
almost	O
entirely	O
by	O
J	O
.	O
Clifford	O
Shaw	O
,	O
a	O
mathematician	O
who	O
worked	O
in	O
Rand	O
's	O
growing	O
computing	O
division	O
.	O
</s>
<s>
It	O
was	O
written	O
in	O
a	O
symbolic	O
assembly	B-Language
language	I-Language
called	O
EasyFox	B-Language
(	O
E	O
and	O
F	O
in	O
the	O
US	O
military	O
's	O
then	O
phonetic	O
alphabet	O
)	O
,	O
also	O
developed	O
by	O
Shaw	O
.	O
</s>
<s>
The	O
JOSS	B-Language
system	O
was	O
brought	O
up	O
formally	O
for	O
the	O
first	O
time	O
in	O
May	O
1963	O
,	O
supporting	O
five	O
consoles	O
,	O
one	O
in	O
the	O
machine	O
room	O
and	O
another	O
four	O
in	O
offices	O
around	O
the	O
building	O
.	O
</s>
<s>
The	O
first	O
schedule	O
was	O
published	O
on	O
17	O
June	O
,	O
with	O
JOSS	B-Language
running	O
for	O
three	O
hours	O
from	O
9am	O
to	O
12	O
every	O
day	O
.	O
</s>
<s>
By	O
this	O
time	O
the	O
JOHNNIAC	B-Device
was	O
already	O
over	O
a	O
decade	O
old	O
,	O
and	O
its	O
tube-based	O
logic	O
was	O
never	O
highly	O
reliable	O
to	O
begin	O
with	O
.	O
</s>
<s>
In	O
May	O
1964	O
,	O
the	O
decision	O
was	O
made	O
to	O
look	O
for	O
a	O
new	O
machine	O
to	O
replace	O
the	O
JOHNNIAC	B-Device
and	O
dedicate	O
it	O
entirely	O
to	O
running	O
an	O
expanded	O
version	O
of	O
JOSS	B-Language
.	O
</s>
<s>
Digital	O
Equipment	O
Corporation	O
(	O
DEC	O
)	O
won	O
the	O
contest	O
with	O
their	O
new	O
PDP-6	B-Device
system	O
,	O
and	O
Air	O
Force	O
funding	O
was	O
released	O
for	O
the	O
purchase	O
.	O
</s>
<s>
The	O
PDP-6	B-Device
arrived	O
in	O
late	O
July	O
1965	O
,	O
and	O
was	O
initially	O
tested	O
using	O
Teletype	B-Application
Model	I-Application
33	I-Application
's	O
as	O
terminals	O
.	O
</s>
<s>
With	O
the	O
new	O
machine	O
up	O
and	O
running	O
,	O
JOHNNIAC	B-Device
was	O
taken	O
offline	O
on	O
11	O
February	O
1966	O
,	O
and	O
officially	O
retired	O
on	O
18	O
February	O
.	O
</s>
<s>
Its	O
last	O
running	O
program	O
was	O
written	O
in	O
JOSS	B-Language
and	O
counted	O
down	O
seconds	O
until	O
it	O
would	O
be	O
turned	O
off	O
.	O
</s>
<s>
Having	O
been	O
replaced	O
by	O
the	O
JOSS-2	O
system	O
,	O
the	O
original	O
was	O
retroactively	O
known	O
as	O
JOSS-1	O
.	O
</s>
<s>
By	O
the	O
end	O
of	O
1966	O
the	O
new	O
JOSS-2	O
system	O
was	O
fully	O
functional	O
and	O
turned	O
over	O
to	O
JOSS	B-Language
use	O
24/7	O
.	O
</s>
<s>
To	O
support	O
them	O
,	O
the	O
custom	O
terminals	O
were	O
equipped	O
with	O
special	O
"	O
JOSS	B-Language
plugs	O
"	O
so	O
they	O
could	O
be	O
wheeled	O
from	O
office	O
to	O
office	O
and	O
plugged	O
into	O
custom	O
outlets	O
.	O
</s>
<s>
The	O
custom	O
terminals	O
had	O
been	O
designed	O
for	O
JOSS	B-Language
as	O
the	O
engineers	O
felt	O
that	O
the	O
Model	O
33	O
's	O
"	O
telecommunications	O
functions	O
are	O
a	O
mystery	O
to	O
the	O
untrained	O
person	O
"	O
and	O
would	O
be	O
too	O
confusing	O
for	O
the	O
occasional	O
users	O
to	O
bother	O
learning	O
.	O
</s>
<s>
Uses	O
were	O
enthusiastic	O
and	O
to	O
serve	O
them	O
,	O
Rand	O
began	O
publishing	O
The	O
JOSS	B-Language
Newsletter	O
,	O
edited	O
by	O
Shirley	O
Marks	O
.	O
</s>
<s>
In	O
the	O
early	O
1970s	O
,	O
programmers	O
at	O
one	O
of	O
IBM	O
's	O
west	O
coast	O
facilities	O
built	O
a	O
JOSS-3	O
for	O
the	O
IBM	B-Device
370/158	I-Device
running	O
OS/360	B-Application
.	O
</s>
<s>
Little	O
information	O
about	O
this	O
system	O
exists	O
,	O
with	O
the	O
exception	O
that	O
it	O
was	O
on	O
this	O
machine	O
that	O
JOSS	B-Language
finally	O
retired	O
.	O
</s>
<s>
According	O
to	O
a	O
note	O
in	O
a	O
historical	O
overview	O
,	O
Rand	O
was	O
hesitant	O
to	O
allow	O
IBM	O
to	O
use	O
the	O
JOSS	B-Language
name	O
,	O
and	O
as	O
a	O
result	O
"	O
the	O
IBM	O
version	O
was	O
never	O
widely	O
used.	O
"	O
</s>
<s>
JOSS-II	O
on	O
the	O
PDP-6	B-Device
was	O
divided	O
into	O
two	O
parts	O
,	O
matching	O
the	O
internal	O
memory	O
layout	O
of	O
the	O
machine	O
.	O
</s>
<s>
The	O
machine	O
was	O
equipped	O
with	O
two	O
banks	O
of	O
core	B-General_Concept
memory	I-General_Concept
,	O
with	O
16k	O
36-bit	O
words	O
in	O
each	O
bank	O
.	O
</s>
<s>
The	O
JOSS	B-Language
system	O
itself	O
,	O
which	O
included	O
the	O
operating	B-General_Concept
system	I-General_Concept
,	O
user	O
and	O
file	O
management	O
code	O
,	O
terminal	O
handler	O
and	O
the	O
interpreter	O
,	O
used	O
up	O
much	O
of	O
the	O
first	O
of	O
these	O
banks	O
.	O
</s>
<s>
Although	O
this	O
was	O
a	O
relatively	O
large	O
amount	O
of	O
memory	O
for	O
the	O
era	O
,	O
the	O
system	O
was	O
so	O
heavily	O
used	O
that	O
the	O
16k	O
word	O
user	O
store	O
was	O
not	O
enough	O
,	O
and	O
it	O
was	O
backed	O
up	O
with	O
a	O
magnetic	B-General_Concept
drum	I-General_Concept
for	O
paging	O
support	O
.	O
</s>
<s>
In	O
order	O
to	O
support	O
multiple	O
user	O
programs	O
,	O
the	O
PDP-6	B-Device
hardware	O
was	O
modified	O
to	O
examine	O
bit-20	O
of	O
any	O
address	O
reference	O
.	O
</s>
<s>
In	O
this	O
way	O
,	O
user	O
programs	O
could	O
be	O
moved	O
about	O
in	O
memory	O
without	O
causing	O
problems	O
for	O
the	O
system	O
,	O
and	O
the	O
operating	B-General_Concept
system	I-General_Concept
could	O
switch	O
from	O
user	O
to	O
user	O
simply	O
by	O
changing	O
a	O
single	O
internal	O
register	O
.	O
</s>
<s>
Permanent	O
storage	O
was	O
provided	O
by	O
a	O
Storage	O
Products	O
hard	B-Device
drive	I-Device
with	O
5.7	O
million	O
words	O
of	O
storage	O
.	O
</s>
<s>
Like	O
the	O
drum	O
,	O
the	O
actual	O
input/output	B-General_Concept
to	O
and	O
from	O
the	O
drum	O
was	O
handled	O
externally	O
,	O
although	O
in	O
this	O
case	O
the	O
movement	O
was	O
triggered	O
by	O
user	O
actions	O
to	O
load	O
and	O
store	O
their	O
programs	O
.	O
</s>
<s>
Terminals	O
were	O
handled	O
through	O
a	O
custom	O
"	O
concentrator	O
"	O
that	O
consisted	O
of	O
a	O
mechanical	O
Strowger	B-Device
switch	I-Device
that	O
could	O
connect	O
any	O
of	O
the	O
300	O
to	O
400	O
possible	O
terminal	O
plugs	O
to	O
any	O
of	O
40	O
outputs	O
.	O
</s>
<s>
A	O
further	O
eight	O
lines	O
were	O
dedicated	O
to	O
Teletype	B-Application
Model	I-Application
33	I-Application
inputs	O
,	O
as	O
opposed	O
to	O
the	O
JOSS-style	O
Selectrics	O
.	O
</s>
<s>
Those	O
48	O
lines	O
were	O
then	O
connected	O
to	O
an	O
electronic	O
multiplexer	B-Protocol
connected	O
to	O
the	O
CPU	O
.	O
</s>
<s>
The	O
multiplexer	B-Protocol
was	O
interrupt	B-Application
driven	O
,	O
meaning	O
idle	O
terminals	O
did	O
not	O
use	O
up	O
any	O
cycles	O
.	O
</s>
<s>
The	O
custom	O
JOSS	B-Language
terminals	O
were	O
built	O
by	O
DEC	O
.	O
</s>
<s>
JOSS	B-Language
introduced	O
the	O
idea	O
of	O
a	O
single	O
command	B-Application
line	I-Application
editor	O
that	O
worked	O
both	O
as	O
an	O
interactive	O
language	O
and	O
a	O
program	O
editor	O
.	O
</s>
<s>
Commands	O
that	O
were	O
typed	O
without	O
a	O
line	B-Application
number	I-Application
were	O
executed	O
immediately	O
,	O
in	O
what	O
JOSS	B-Language
referred	O
to	O
as	O
"	O
direct	B-Application
mode	I-Application
"	O
.	O
</s>
<s>
If	O
the	O
same	O
line	O
was	O
prefixed	O
with	O
a	O
line	B-Application
number	I-Application
,	O
it	O
was	O
instead	O
copied	O
into	O
the	O
program	O
code	O
storage	O
area	O
,	O
which	O
JOSS	B-Language
called	O
"	O
indirect	O
mode	O
"	O
.	O
</s>
<s>
New	O
lines	O
were	O
added	O
to	O
the	O
program	O
if	O
the	O
line	B-Application
number	I-Application
was	O
unique	O
,	O
replaced	O
extant	O
lines	O
with	O
the	O
same	O
number	O
,	O
or	O
removed	O
from	O
the	O
program	O
if	O
an	O
extant	O
line	B-Application
number	I-Application
was	O
typed	O
in	O
with	O
no	O
code	O
following	O
it	O
.	O
</s>
<s>
In	O
contrast	O
to	O
most	O
BASICs	O
,	O
JOSS	B-Language
saved	O
the	O
entire	O
user	B-General_Concept
input	I-General_Concept
to	O
files	O
,	O
not	O
just	O
the	O
program	O
code	O
.	O
</s>
<s>
When	O
loaded	O
,	O
JOSS	B-Language
essentially	O
typed	O
the	O
lines	O
back	O
in	O
.	O
</s>
<s>
This	O
meant	O
that	O
program	O
files	O
could	O
contain	O
both	O
program	O
statements	O
and	O
direct	B-Application
mode	I-Application
instructions	O
.	O
</s>
<s>
There	O
were	O
some	O
features	O
that	O
could	O
only	O
be	O
used	O
in	O
direct	B-Application
mode	I-Application
,	O
like	O
and	O
,	O
which	O
were	O
input	O
without	O
line	B-Application
numbers	I-Application
but	O
still	O
returned	O
when	O
the	O
program	O
was	O
loaded	O
.	O
</s>
<s>
Every	O
line	O
in	O
a	O
JOSS	B-Language
program	O
must	O
start	O
with	O
a	O
line	B-Application
number	I-Application
.	O
</s>
<s>
Line	B-Application
numbers	I-Application
are	O
fixed-point	O
numbers	O
consisting	O
of	O
two	O
two-digit	O
integers	O
separated	O
by	O
a	O
period	O
.	O
</s>
<s>
As	O
in	O
BASIC	O
,	O
line	B-Application
numbers	I-Application
are	O
used	O
both	O
as	O
labels	O
to	O
target	O
from	O
and	O
statements	O
,	O
and	O
to	O
support	O
editing	O
.	O
</s>
<s>
Entering	O
a	O
line	O
of	O
code	O
with	O
a	O
new	O
line	B-Application
number	I-Application
inserts	O
it	O
into	O
a	O
program	O
,	O
while	O
entering	O
one	O
with	O
an	O
extant	O
line	B-Application
number	I-Application
replaces	O
the	O
prior	O
version	O
or	O
deletes	O
it	O
if	O
it	O
is	O
empty	O
.	O
</s>
<s>
The	O
portion	O
of	O
the	O
line	B-Application
number	I-Application
to	O
the	O
left	O
of	O
the	O
period	O
is	O
termed	O
the	O
page	O
or	O
part	O
,	O
while	O
the	O
portion	O
to	O
the	O
right	O
is	O
termed	O
the	O
line	O
.	O
</s>
<s>
Thus	O
the	O
line	B-Application
number	I-Application
refers	O
to	O
page	O
10	O
,	O
line	O
12	O
.	O
</s>
<s>
Branches	B-General_Concept
can	O
target	O
either	O
a	O
page	O
,	O
or	O
a	O
line	O
within	O
a	O
page	O
.	O
</s>
<s>
Every	O
line	O
must	O
start	O
with	O
a	O
command	B-Application
keyword	O
following	O
the	O
line	B-Application
number	I-Application
.	O
</s>
<s>
No	O
concept	O
of	O
a	O
default	O
command	B-Application
exists	O
as	O
is	O
the	O
case	O
in	O
BASIC	O
with	O
its	O
optional	O
statement	O
.	O
</s>
<s>
JOSS	B-Language
uses	O
a	O
suffix	O
notation	O
to	O
indicate	O
conditional	B-Language
evaluation	O
,	O
"	O
do	O
this	O
if	O
this	O
is	O
true	O
"	O
,	O
in	O
contrast	O
to	O
most	O
languages	O
which	O
place	O
the	O
condition	O
in	O
front	O
in	O
prefix	O
notation	O
,	O
"	O
if	O
this	O
is	O
true	O
,	O
do	O
this	O
"	O
.	O
</s>
<s>
Like	O
BASIC	O
,	O
but	O
unlike	O
FORTRAN	B-Application
or	O
FOCAL	B-Language
,	O
any	O
statement	O
can	O
be	O
conditionally	O
evaluated	O
in	O
this	O
fashion	O
.	O
</s>
<s>
JOSS	B-Language
supported	O
six	O
infix	O
comparisons	O
,	O
,	O
,	O
,	O
,	O
,	O
,	O
and	O
boolean	O
operators	O
,	O
,	O
and	O
.	O
</s>
<s>
Loops	O
were	O
handled	O
in	O
a	O
similar	O
fashion	O
,	O
using	O
the	O
command	B-Application
and	O
a	O
somewhat	O
obscure	O
format	O
for	O
specifying	O
the	O
loop	O
bounds	O
and	O
step	O
value	O
,	O
.	O
</s>
<s>
5.2	O
Type	O
"	O
This	O
is	O
JOSS	B-Language
.	O
</s>
<s>
As	O
in	O
BASIC	O
,	O
any	O
of	O
the	O
inputs	O
to	O
the	O
for	B-Language
loop	I-Language
could	O
be	O
constants	O
,	O
variables	O
or	O
other	O
expressions	O
.	O
</s>
<s>
A	O
unique	O
feature	O
of	O
JOSS	B-Language
was	O
its	O
handling	O
of	O
logical	O
expressions	O
.	O
</s>
<s>
JOSS	B-Language
expanded	O
on	O
this	O
concept	O
by	O
clearly	O
defining	O
the	O
concept	O
of	O
the	O
"	O
proposition	O
"	O
,	O
an	O
expression	O
that	O
returns	O
a	O
logical	O
value	O
,	O
true	O
or	O
false	O
,	O
instead	O
of	O
a	O
numeric	O
one	O
.	O
</s>
<s>
In	O
addition	O
to	O
propositions	O
,	O
JOSS	B-Language
also	O
had	O
the	O
concept	O
of	O
"	O
conditional	B-Language
expressions	O
"	O
.	O
</s>
<s>
They	O
serve	O
a	O
purpose	O
similar	O
to	O
the	O
ternary	O
operator	O
found	O
in	O
modern	O
languages	O
like	O
C	B-Language
or	O
Java	B-Language
,	O
where	O
they	O
are	O
used	O
to	O
return	O
a	O
value	O
from	O
a	O
compact	O
structure	O
implementing	O
if-then-else	B-Language
.	O
</s>
<s>
JOSS	B-Language
 '	O
version	O
has	O
any	O
number	O
of	O
conditionals	B-Language
,	O
not	O
just	O
three	O
,	O
so	O
it	O
is	O
more	O
of	O
a	O
compact	O
switch	O
statement	O
than	O
a	O
compact	O
if-then	B-Language
.	O
</s>
<s>
Another	O
advanced	O
feature	O
of	O
JOSS	B-Language
was	O
that	O
it	O
had	O
the	O
concept	O
of	O
a	O
range	B-Data_Structure
as	O
a	O
built-in	O
type	O
that	O
could	O
be	O
stored	O
and	O
manipulated	O
.	O
</s>
<s>
Ranges	O
are	O
normally	O
found	O
as	O
the	O
inputs	O
to	O
for	B-Language
loops	I-Language
,	O
where	O
they	O
are	O
part	O
of	O
the	O
syntax	O
of	O
the	O
loop	O
itself	O
.	O
</s>
<s>
For	O
instance	O
,	O
in	O
BASIC	O
one	O
writes	O
a	O
for	B-Language
loop	I-Language
using	O
this	O
basic	O
syntax	O
:	O
</s>
<s>
JOSS	B-Language
used	O
a	O
somewhat	O
obscure	O
format	O
to	O
define	O
the	O
limits	O
of	O
the	O
loop	O
.	O
</s>
<s>
The	O
equivalent	O
code	O
in	O
JOSS	B-Language
would	O
be	O
:	O
</s>
<s>
That	O
is	O
because	O
in	O
JOSS	B-Language
,	O
ranges	O
are	O
first-class	O
citizens	O
of	O
the	O
language	O
,	O
not	O
something	O
that	O
is	O
part	O
of	O
a	O
loop	O
as	O
in	O
BASIC	O
.	O
</s>
<s>
For	O
example	O
,	O
here	O
is	O
a	O
conditional	B-Language
expression	O
that	O
evaluates	O
the	O
factorial	O
of	O
a	O
parameter	O
x	O
:	O
</s>
<s>
This	O
one	O
checks	O
if	O
the	O
fractional	O
part	O
of	O
x	O
is	O
zero	O
(	O
i.e.	O
,	O
it	O
is	O
an	O
integer	O
)	O
,	O
and	O
if	O
so	O
,	O
it	O
calls	O
the	O
function	O
to	O
multiply	O
a	O
range	B-Data_Structure
of	O
values	O
.	O
</s>
<s>
JOSS	B-Language
's	O
capability	O
to	O
combine	O
decisions	O
and	O
loops	O
in	O
a	O
compact	O
form	O
is	O
unknown	O
in	O
other	O
languages	O
of	O
the	O
era	O
,	O
including	O
offshoots	O
like	O
FOCAL	B-Language
.	O
</s>
<s>
The	O
command	B-Application
assigns	O
the	O
results	O
of	O
an	O
expression	O
to	O
the	O
specified	O
variable	O
.	O
</s>
<s>
was	O
optional	O
when	O
used	O
in	O
direct	B-Application
mode	I-Application
,	O
where	O
one	O
could	O
type	O
without	O
the	O
Set	O
command	B-Application
.	O
</s>
<s>
The	O
system	O
generally	O
suggested	O
using	O
only	O
in	O
direct	B-Application
mode	I-Application
,	O
saving	O
them	O
out	O
for	O
use	O
in	O
a	O
program	O
by	O
inserting	O
them	O
at	O
the	O
top	O
or	O
bottom	O
of	O
the	O
file	O
.	O
</s>
<s>
The	O
takes	O
a	O
list	O
of	O
variables	O
and	O
stores	O
the	O
user	B-General_Concept
input	I-General_Concept
in	O
variables	O
.	O
</s>
<s>
The	O
command	B-Application
outputs	O
one	O
or	O
more	O
items	O
separated	O
by	O
commas	O
.	O
</s>
<s>
However	O
,	O
includes	O
a	O
number	O
of	O
optional	O
forms	O
that	O
make	O
it	O
highly	O
overloaded	O
,	O
performing	O
a	O
range	B-Data_Structure
of	O
unrelated	O
output	O
tasks	O
.	O
</s>
<s>
triggers	O
a	O
page	O
feed	O
on	O
the	O
special	O
JOSS	B-Language
terminals	O
.	O
</s>
<s>
JOSS	B-Language
would	O
normally	O
send	O
a	O
page	O
feed	O
when	O
the	O
terminal	O
reached	O
line	O
54	O
on	O
the	O
paper	O
,	O
so	O
if	O
one	O
wanted	O
to	O
ensure	O
a	O
block	O
of	O
data	O
would	O
not	O
be	O
split	O
in	O
half	O
,	O
one	O
could	O
:	O
</s>
<s>
is	O
a	O
pseudo-variable	O
that	O
returns	O
the	O
current	O
line	B-Application
number	I-Application
.	O
</s>
<s>
triggers	O
a	O
line	O
feed	O
on	O
the	O
special	O
JOSS	B-Language
terminals	O
.	O
</s>
<s>
The	O
command	B-Application
jumps	O
program	O
execution	O
to	O
the	O
specified	O
part	O
or	O
step	O
number	O
,	O
using	O
or	O
respectively	O
.	O
</s>
<s>
Contrast	O
with	O
,	O
an	O
indirect	O
command	B-Application
used	O
from	O
the	O
command	B-Application
line	I-Application
that	O
starts	O
programs	O
,	O
the	O
equivalent	O
of	O
BASIC	O
's	O
.	O
</s>
<s>
is	O
similar	O
to	O
,	O
but	O
branches	B-General_Concept
to	O
a	O
subroutine	O
.	O
</s>
<s>
JOSS	B-Language
maintains	O
a	O
pointer	O
to	O
the	O
currently	O
executing	O
line	O
,	O
which	O
a	O
would	O
change	O
.	O
</s>
<s>
However	O
,	O
it	O
included	O
a	O
special	O
"	O
parenthetic	O
do	O
"	O
that	O
could	O
be	O
used	O
in	O
direct	B-Application
mode	I-Application
to	O
test	O
certain	O
sections	O
of	O
the	O
code	O
without	O
changing	O
the	O
main	O
pointer	O
.	O
</s>
<s>
The	O
command	B-Application
returns	O
from	O
a	O
subroutine	O
call	O
.	O
</s>
<s>
As	O
subroutines	O
return	O
automatically	O
when	O
the	O
end	O
of	O
the	O
part	O
is	O
reached	O
,	O
is	O
only	O
required	O
for	O
returning	O
early	O
,	O
and	O
is	O
often	O
used	O
with	O
a	O
conditional	B-Language
.	O
</s>
<s>
The	O
command	B-Application
terminates	O
execution	O
of	O
the	O
program	O
and	O
returns	O
control	O
to	O
the	O
editing	O
environment	O
.	O
</s>
<s>
Equivalent	O
to	O
BASIC	O
's	O
or	O
,	O
although	O
BASIC	O
's	O
is	O
intended	O
to	O
allow	O
to	O
pick	O
up	O
execution	O
at	O
the	O
same	O
location	O
,	O
a	O
feature	O
that	O
has	O
no	O
direct	O
equivalent	O
in	O
JOSS	B-Language
's	O
workspace-oriented	O
system	O
.	O
</s>
<s>
Available	O
in	O
direct	B-Application
mode	I-Application
only	O
,	O
is	O
the	O
equivalent	O
to	O
BASIC	O
's	O
and	O
,	O
depending	O
on	O
whether	O
a	O
program	O
is	O
currently	O
stopped	O
due	O
to	O
an	O
error	O
or	O
command	B-Application
being	O
encountered	O
.	O
</s>
<s>
Another	O
direct-mode-only	O
command	B-Application
,	O
is	O
used	O
when	O
the	O
program	O
has	O
stopped	O
for	O
an	O
error	O
and	O
the	O
user	O
wants	O
to	O
reset	O
the	O
program	O
,	O
which	O
it	O
does	O
by	O
clearing	O
the	O
program	B-General_Concept
counter	I-General_Concept
.	O
</s>
<s>
JOSS	B-Language
stored	O
all	O
numbers	O
as	O
radix-10	O
floating	O
point	O
.	O
</s>
<s>
JOSS	B-Language
contained	O
six	O
mathematical	O
operators	O
:	O
</s>
<s>
JOSS	B-Language
also	O
defined	O
a	O
number	O
of	O
functions	O
that	O
performed	O
looping	O
internally	O
,	O
in	O
order	O
to	O
avoid	O
the	O
programmer	O
having	O
to	O
write	O
a	O
loop	O
to	O
perform	O
simple	O
tasks	O
like	O
summing	O
a	O
series	O
of	O
numbers	O
.	O
</s>
<s>
The	O
parameters	O
could	O
be	O
either	O
a	O
list	O
of	O
simple	O
expressions	O
separated	O
by	O
commas	O
,	O
or	O
a	O
range	B-Data_Structure
construct	O
whose	O
command	B-Application
could	O
be	O
any	O
statement	O
or	O
function	O
call	O
.	O
</s>
<s>
The	O
JOSS	B-Language
system	O
used	O
a	O
hard	B-Device
disk	I-Device
to	O
store	O
user	O
programs	O
in	O
an	O
allocated	O
space	O
.	O
</s>
<s>
The	O
integer	O
part	O
is	O
the	O
equivalent	O
of	O
a	O
directory	O
,	O
and	O
the	O
name	O
is	O
the	O
sub-file	O
within	O
it	O
,	O
maintained	O
by	O
JOSS	B-Language
itself	O
.	O
</s>
<s>
There	O
are	O
some	O
syntactic	O
differences	O
from	O
the	O
original	O
JOSS	B-Language
language	O
.	O
</s>
