<s>
The	O
LINC	B-Device
(	O
Laboratory	B-Device
INstrument	I-Device
Computer	I-Device
)	O
is	O
a	O
12-bit	B-Device
,	O
2048-word	O
transistorized	B-Device
computer	I-Device
.	O
</s>
<s>
The	O
LINC	B-Device
is	O
considered	O
by	O
some	O
the	O
first	O
minicomputer	B-Architecture
and	O
a	O
forerunner	O
to	O
the	O
personal	B-Device
computer	I-Device
.	O
</s>
<s>
Originally	O
named	O
the	O
"	O
Linc	B-Device
"	O
,	O
suggesting	O
the	O
project	O
's	O
origins	O
at	O
MIT	O
's	O
Lincoln	O
Laboratory	O
,	O
it	O
was	O
renamed	O
LINC	B-Device
after	O
the	O
project	O
moved	O
from	O
the	O
Lincoln	O
Laboratory	O
.	O
</s>
<s>
The	O
LINC	B-Device
was	O
designed	O
by	O
Wesley	O
A	O
.	O
Clark	O
and	O
Charles	O
Molnar	O
.	O
</s>
<s>
The	O
LINC	B-Device
and	O
other	O
"	O
MIT	O
Group	O
"	O
machines	O
were	O
designed	O
at	O
MIT	O
and	O
eventually	O
built	O
by	O
Digital	O
Equipment	O
Corporation	O
(	O
DEC	O
)	O
and	O
Spear	O
Inc	O
.	O
of	O
Waltham	O
,	O
Massachusetts	O
(	O
later	O
a	O
division	O
of	O
Becton	O
,	O
Dickinson	O
and	O
Company	O
)	O
.	O
</s>
<s>
The	O
LINC	B-Device
sold	O
for	O
more	O
than	O
$	O
40,000	O
at	O
the	O
time	O
.	O
</s>
<s>
A	O
typical	O
configuration	O
included	O
an	O
enclosed	O
6'X20	O
"	O
rack	B-Application
;	O
four	O
boxes	O
holding	O
(	O
1	O
)	O
two	O
tape	O
drives	O
,	O
(	O
2	O
)	O
display	O
scope	O
and	O
input	O
knobs	O
,	O
(	O
3	O
)	O
control	O
console	O
and	O
(	O
4	O
)	O
data	O
terminal	O
interface	O
;	O
and	O
a	O
keyboard	O
.	O
</s>
<s>
The	O
LINC	B-Device
interfaced	O
well	O
with	O
laboratory	O
experiments	O
.	O
</s>
<s>
The	O
LINC	B-Device
's	O
design	O
was	O
literally	O
in	O
the	O
public	O
domain	O
,	O
perhaps	O
making	O
it	O
unique	O
in	O
the	O
history	O
of	O
computers	O
.	O
</s>
<s>
A	O
dozen	O
LINC	B-Device
computers	O
were	O
assembled	O
by	O
their	O
eventual	O
biomedical	O
researcher	O
owners	O
in	O
a	O
1963	O
summer	O
workshop	O
at	O
MIT	O
.	O
</s>
<s>
DEC	O
's	O
pioneer	O
C	O
.	O
Gordon	O
Bell	O
states	O
that	O
the	O
LINC	B-Device
project	O
began	O
in	O
1961	O
,	O
with	O
first	O
delivery	O
in	O
March	O
1962	O
,	O
and	O
the	O
machine	O
was	O
not	O
formally	O
withdrawn	O
until	O
December	O
1969	O
.	O
</s>
<s>
The	O
first	O
LINC	B-Device
included	O
two	O
oscilloscope	O
displays	O
.	O
</s>
<s>
In	O
these	O
,	O
the	O
tall	O
cabinet	O
sitting	O
behind	O
a	O
white	O
Formica-covered	O
table	O
held	O
two	O
somewhat	O
smaller	O
metal	O
boxes	O
holding	O
the	O
same	O
instrumentation	O
,	O
a	O
Tektronix	O
display	O
oscilloscope	O
over	O
the	O
"	O
front	O
panel	O
"	O
on	O
the	O
user	O
's	O
left	O
,	O
a	O
bay	O
for	O
interfaces	O
over	O
two	O
LINC-Tape	O
drives	O
on	O
the	O
user	O
's	O
right	O
,	O
and	O
a	O
chunky	O
keyboard	O
between	O
them	O
.	O
</s>
<s>
The	O
standard	O
program	O
development	O
software	O
(	O
an	O
assembler/editor	O
)	O
was	O
designed	O
by	O
Mary	O
Allen	O
Wilkes	O
;	O
the	O
last	O
version	O
was	O
named	O
LAP6	O
(	O
LINC	B-Device
Assembly	O
Program	O
6	O
)	O
.	O
</s>
<s>
The	O
LINC	B-Device
had	O
2048	O
12-bit	B-Device
words	O
of	O
memory	O
in	O
two	O
sections	O
.	O
</s>
<s>
Programs	O
could	O
use	O
a	O
12-bit	B-Device
accumulator	O
and	O
a	O
one-bit	O
link	O
register	O
.	O
</s>
<s>
Location	O
0	O
supported	O
the	O
single-level	O
of	O
subroutine	B-Algorithm
call	O
,	O
automatically	O
being	O
updated	O
with	O
a	O
return	O
address	O
on	O
every	O
jump	O
instruction	O
.	O
</s>
<s>
A	O
later	O
modification	O
to	O
the	O
LINC	B-Device
added	O
a	O
12-bit	B-Device
Z	O
register	O
to	O
facilitate	O
extended	O
precision	O
arithmetic	O
,	O
and	O
an	O
interrupt	O
was	O
provided	O
forcing	O
execution	O
to	O
location	O
21	O
(	O
octal	O
)	O
.	O
</s>
<s>
The	O
original	O
LINC	B-Device
required	O
8	O
microseconds	O
for	O
each	O
instruction	O
.	O
</s>
<s>
The	O
natural	O
notation	O
used	O
for	O
the	O
LINC	B-Device
was	O
octal	O
.	O
</s>
<s>
The	O
LINC	B-Device
instruction	O
set	O
was	O
designed	O
for	O
ease	O
of	O
use	O
with	O
scientific	O
instruments	O
or	O
custom	O
experimental	O
apparatus	O
.	O
</s>
<s>
immediate	O
address	O
given	O
in	O
second	O
12-bit	B-Device
word	O
of	O
the	O
opcode	O
-	O
add	O
,	O
store	O
and	O
clear	O
accumulator	O
,	O
jump	O
.	O
</s>
<s>
Skip	O
class	O
,	O
skips	O
the	O
next	B-General_Concept
instruction	I-General_Concept
,	O
can	O
test	O
for	O
set	O
or	O
clear	O
condition	O
.	O
</s>
<s>
The	O
LINC	B-Device
control	O
panel	O
was	O
used	O
for	O
single-stepping	O
through	O
programs	O
and	O
for	O
program	O
debugging	O
.	O
</s>
<s>
Execution	O
could	O
be	O
stopped	O
when	O
the	O
program	B-General_Concept
counter	I-General_Concept
matched	O
a	O
set	O
of	O
switches	O
.	O
</s>
<s>
A	O
noteworthy	O
feature	O
of	O
the	O
LINC	B-Device
was	O
the	O
LINCtape	O
.	O
</s>
<s>
Since	O
the	O
basic	O
LINC	B-Device
had	O
only	O
1024	O
12-bit	B-Device
words	O
of	O
core	O
memory	O
(	O
RAM	O
)	O
--and	O
the	O
big	O
,	O
expanded	O
LINC	B-Device
had	O
only	O
2048	O
—	O
normal	O
operations	O
depended	O
heavily	O
on	O
swapping	O
to	O
and	O
from	O
LINCtape	O
.	O
</s>
<s>
LINC	B-Device
users	O
demonstrated	O
this	O
by	O
punching	O
holes	O
in	O
a	O
tape	O
with	O
an	O
ordinary	O
office	O
paper	O
punch	O
.	O
</s>
<s>
The	O
LINC	B-Device
keyboard	O
,	O
manufactured	O
by	O
company	O
named	O
Soroban	O
Engineering	O
,	O
had	O
a	O
unique	O
locking	O
solenoid	O
.	O
</s>
<s>
This	O
could	O
have	O
the	O
effect	O
of	O
slowing	O
down	O
typing	O
and	O
preventing	O
even	O
2-key	B-Device
rollover	I-Device
.	O
</s>
<s>
This	O
exotic	O
keyboard	O
was	O
abandoned	O
in	O
favor	O
of	O
Teletype	O
keyboards	O
,	O
such	O
as	O
the	O
Model	O
35	O
KSR	O
and	O
Model	O
37	O
KSR	O
,	O
in	O
the	O
LINC-8	B-Device
and	O
PDP-12	B-Device
follow-on	O
computers	O
.	O
</s>
<s>
The	O
LINC	B-Device
included	O
a	O
set	O
of	O
eight	O
three-turn	O
potentiometers	O
(	O
numbered	O
0-7	O
)	O
that	O
could	O
be	O
each	O
be	O
read	O
by	O
a	O
computer	O
instruction	O
.	O
</s>
<s>
The	O
dial	B-Device
box	I-Device
was	O
a	O
convenient	O
user	O
input	O
device	O
at	O
a	O
time	O
before	O
general	O
adoption	O
of	O
the	O
mouse	B-Device
.	O
</s>
<s>
The	O
LINC	B-Device
hardware	O
allowed	O
a	O
12-bit	B-Device
word	O
to	O
be	O
rapidly	O
and	O
automatically	O
displayed	O
on	O
the	O
screen	O
as	O
a	O
4-wide	O
by	O
6-high	O
matrix	O
of	O
pixels	O
,	O
making	O
it	O
possible	O
to	O
display	O
full	O
screens	O
of	O
flicker-free	O
text	O
with	O
a	O
minimum	O
of	O
dedicated	O
hardware	O
.	O
</s>
<s>
The	O
standard	O
display	O
routines	O
generated	O
4	O
by	O
6	O
character	O
cells	O
,	O
giving	O
the	O
LINC	B-Device
one	O
of	O
the	O
coarsest	O
character	O
sets	O
ever	O
designed	O
.	O
</s>
<s>
Many	O
LINCs	B-Device
were	O
supplied	O
as	O
kits	O
to	O
be	O
assembled	O
by	O
the	O
end	O
user	O
,	O
so	O
the	O
oscilloscope	O
came	O
in	O
handy	O
.	O
</s>
<s>
The	O
y-axis	O
displayed	O
both	O
plus	O
and	O
minus	O
zero	O
as	O
different	O
values	O
,	O
unnecessarily	O
reflecting	O
the	O
fact	O
that	O
the	O
LINC	B-Device
used	O
ones	O
 '	O
complement	O
arithmetic	O
.	O
</s>
<s>
Notoriously	O
,	O
a	O
tight	O
loop	O
that	O
displayed	O
points	O
repetitively	O
in	O
one	O
place	O
on	O
the	O
screen	O
would	O
burn	B-General_Concept
a	I-General_Concept
permanent	I-General_Concept
dark	I-General_Concept
hole	I-General_Concept
in	O
the	O
delicate	O
phosphor	O
in	O
well	O
under	O
a	O
minute	O
;	O
programmers	O
had	O
to	O
be	O
ready	O
to	O
hit	O
the	O
Stop	O
lever	O
fast	O
if	O
a	O
very	O
bright	O
spot	O
suddenly	O
appeared	O
because	O
of	O
a	O
programming	O
mistake	O
.	O
</s>
<s>
Printed	O
output	O
on	O
a	O
Teletype	B-Application
Model	I-Application
33	I-Application
ASR	O
was	O
controlled	O
by	O
a	O
single	O
pole	O
relay	O
.	O
</s>
<s>
A	O
subroutine	B-Algorithm
would	O
convert	O
the	O
LINC	B-Device
character	O
codes	O
into	O
ASCII	O
and	O
use	O
timing	O
loops	O
to	O
toggle	O
the	O
relay	O
on	O
and	O
off	O
,	O
generating	O
the	O
correct	O
8-bit	O
output	O
to	O
control	O
the	O
Teletype	O
printer	O
.	O
</s>
<s>
The	O
LINC	B-Device
connector	O
module	O
included	O
bays	O
for	O
two	O
plug-in	O
chassis	O
allowing	O
custom	O
interfacing	O
to	O
experimental	O
setups	O
.	O
</s>
<s>
In	O
addition	O
to	O
the	O
original	O
"	O
classic	O
"	O
LINC	B-Device
,	O
slight	O
programming	O
variations	O
occurred	O
when	O
using	O
the	O
micro-LINC	O
(μ-	O
LINC	B-Device
)	O
(	O
1965	O
)	O
,	O
micro-LINC	O
300	O
(μ-	O
LINC	B-Device
300	O
)	O
(	O
1968	O
)	O
(	O
integrated	O
circuit	O
 [ MECL ] 	O
versions	O
)	O
,	O
and	O
LINC-8	B-Device
.	O
</s>
<s>
While	O
Bell	O
in	O
his	O
book	O
says	O
designing	O
the	O
LINC	B-Device
provided	O
the	O
ideas	O
for	O
DEC	O
's	O
second	O
and	O
third	O
machines	O
,	O
the	O
PDP-4	B-Device
and	O
the	O
PDP-5	B-Device
.	O
</s>
<s>
Digital	O
Equipment	O
Corporation	O
would	O
launch	O
the	O
extremely	O
successful	O
PDP-8	B-Device
before	O
it	O
manufactured	O
the	O
first	O
next-generation	O
LINC-compatible	O
computer	O
,	O
the	O
LINC-8	B-Device
and	O
a	O
combination	O
PDP-8/I	O
and	O
LINC	B-Device
,	O
combined	O
as	O
the	O
PDP-12	B-Device
.	O
</s>
<s>
DEC	O
's	O
final	O
12-bit	B-Device
lab	O
machine	O
,	O
the	O
Lab-8/E	O
,	O
incorporated	O
the	O
LINC	B-Device
instruction	O
set	O
.	O
</s>
<s>
The	O
first	O
follow-on	O
,	O
the	O
LINC-8	B-Device
,	O
booted	O
(	O
slowly	O
)	O
to	O
a	O
PDP-8	B-Device
program	O
called	O
PROGOFOP	O
(	O
PROGram	O
OF	O
OPeration	O
)	O
which	O
interfaced	O
to	O
the	O
separate	O
LINC	B-Device
hardware	O
.	O
</s>
<s>
The	O
PDP-12	B-Device
was	O
the	O
last	O
and	O
most	O
popular	O
follow-on	O
to	O
the	O
LINC	B-Device
.	O
</s>
<s>
It	O
was	O
a	O
capable	O
and	O
improved	O
machine	O
,	O
and	O
was	O
more	O
stable	O
than	O
the	O
LINC-8	B-Device
,	O
but	O
architecturally	O
was	O
still	O
an	O
imperfect	O
hybrid	O
of	O
a	O
LINC	B-Device
and	O
a	O
PDP-8	B-Device
,	O
full	O
of	O
many	O
small	O
technical	O
glitches	O
.	O
</s>
<s>
(	O
For	O
example	O
,	O
the	O
LINC	B-Device
had	O
an	O
overflow	O
bit	O
which	O
was	O
a	O
small	O
but	O
important	O
part	O
of	O
the	O
LINC	B-Device
's	O
machine	O
state	O
;	O
the	O
PDP-12	B-Device
had	O
no	O
provision	O
for	O
saving	O
and	O
restoring	O
the	O
state	O
of	O
this	O
bit	O
across	O
PDP-8	B-Device
interrupts	O
.	O
)	O
</s>
<s>
The	O
name	O
undoubtedly	O
was	O
intended	O
to	O
evoke	O
memories	O
of	O
the	O
LINC	B-Device
,	O
but	O
the	O
16-bit	O
machine	O
had	O
no	O
architectural	O
resemblance	O
to	O
,	O
or	O
compatibility	O
with	O
,	O
the	O
LINC	B-Device
.	O
</s>
