<s>
In	O
computing	O
,	O
the	O
Blit	B-Algorithm
was	O
a	O
programmable	O
bitmap	O
graphics	O
terminal	B-General_Concept
designed	O
by	O
Rob	O
Pike	O
and	O
Bart	O
Locanthi	O
Jr.	O
of	O
Bell	O
Labs	O
in	O
1982	O
.	O
</s>
<s>
The	O
Blit	B-Algorithm
programmable	O
bitmap	O
graphics	O
terminal	B-General_Concept
was	O
designed	O
by	O
Rob	O
Pike	O
and	O
Bart	O
Locanthi	O
Jr.	O
of	O
Bell	O
Labs	O
in	O
1982	O
.	O
</s>
<s>
The	O
Blit	B-Algorithm
technology	O
was	O
commercialized	O
by	O
AT&T	O
and	O
Teletype	O
.	O
</s>
<s>
The	O
5620	O
used	O
a	O
Western	O
Electric	O
32100	O
processor	O
(	O
aka	O
Bellmac	B-General_Concept
32	I-General_Concept
)	O
and	O
had	O
a	O
15	O
"	O
green	O
phosphor	O
display	O
with	O
800×1024×1	O
resolution	O
(	O
66×88	O
characters	O
in	O
the	O
initial	O
text	O
mode	O
)	O
interlaced	O
at	O
30Hz	O
.	O
</s>
<s>
The	O
630	O
and	O
730	O
had	O
Motorola	B-Device
68000	I-Device
processors	I-Device
and	O
a	O
1024×1024×1	O
monochrome	O
display	O
at	O
60Hz	O
(	O
most	O
had	O
amber	O
displays	O
,	O
but	O
some	O
had	O
white	O
or	O
green	O
displays	O
)	O
.	O
</s>
<s>
The	O
folk	O
etymology	O
for	O
the	O
Blit	B-Algorithm
name	O
is	O
that	O
it	O
stands	O
for	O
Bell	O
Labs	O
Intelligent	O
Terminal	B-General_Concept
,	O
and	O
its	O
creators	O
have	O
also	O
joked	O
that	O
it	O
actually	O
stood	O
for	O
Bacon	O
,	O
Lettuce	O
,	O
and	O
Interactive	O
Tomato	O
.	O
</s>
<s>
However	O
,	O
Rob	O
Pike	O
's	O
paper	O
on	O
the	O
Blit	B-Algorithm
explains	O
that	O
it	O
was	O
named	O
after	O
the	O
second	O
syllable	O
of	O
bit	B-Algorithm
blit	I-Algorithm
,	O
a	O
common	O
name	O
for	O
the	O
bit-block	O
transfer	O
operation	O
that	O
is	O
fundamental	O
to	O
the	O
terminal	B-General_Concept
's	O
graphics	O
.	O
</s>
<s>
Its	O
original	O
nickname	O
was	O
Jerq	B-Protocol
,	O
inspired	O
by	O
a	O
joke	O
used	O
during	O
a	O
demo	O
of	O
a	O
Three	O
Rivers	O
 '	O
PERQ	B-Device
graphic	O
workstation	O
and	O
used	O
with	O
permission	O
.	O
</s>
<s>
When	O
initially	O
switched	O
on	O
,	O
the	O
Blit	B-Algorithm
looked	O
like	O
an	O
ordinary	O
textual	O
"	O
dumb	O
"	O
terminal	B-General_Concept
,	O
although	O
taller	O
than	O
usual	O
.	O
</s>
<s>
However	O
,	O
after	O
logging	O
into	O
a	O
Unix	B-Application
host	O
(	O
connected	O
to	O
the	O
terminal	B-General_Concept
through	O
a	O
serial	B-Protocol
port	I-Protocol
)	O
,	O
the	O
host	O
could	O
(	O
via	O
special	O
escape	O
sequences	O
)	O
load	O
software	O
to	O
be	O
executed	O
by	O
the	O
processor	O
of	O
the	O
terminal	B-General_Concept
.	O
</s>
<s>
This	O
software	O
could	O
make	O
use	O
of	O
the	O
terminal	B-General_Concept
's	O
full	O
graphics	O
capabilities	O
and	O
attached	O
peripherals	O
such	O
as	O
a	O
computer	B-Device
mouse	I-Device
.	O
</s>
<s>
Normally	O
,	O
users	O
would	O
load	O
the	O
window	O
systems	O
mpx	O
(	O
or	O
its	O
successor	O
mux	O
)	O
,	O
which	O
replaced	O
the	O
terminal	B-General_Concept
's	O
user	B-Application
interface	I-Application
by	O
a	O
mouse-driven	O
windowing	O
interface	O
,	O
with	O
multiple	O
terminal	B-Application
windows	I-Application
all	O
multiplexed	O
over	O
the	O
single	O
available	O
serial-line	O
connection	O
to	O
the	O
host	O
.	O
</s>
<s>
Each	O
window	O
initially	O
ran	O
a	O
simple	O
terminal	B-Application
emulator	I-Application
,	O
which	O
could	O
be	O
replaced	O
by	O
a	O
downloaded	O
interactive	O
graphical	O
application	O
,	O
for	O
example	O
a	O
more	O
advanced	O
terminal	B-Application
emulator	I-Application
,	O
an	O
editor	O
,	O
or	O
a	O
clock	O
application	O
.	O
</s>
<s>
The	O
resulting	O
properties	O
were	O
similar	O
to	O
those	O
of	O
a	O
modern	O
Unix	B-Application
windowing	O
system	O
;	O
however	O
,	O
to	O
avoid	O
having	O
user	O
interaction	O
slowed	O
by	O
the	O
serial	O
connection	O
,	O
the	O
interactive	B-Application
interface	I-Application
and	O
the	O
host	O
application	O
ran	O
on	O
separate	O
systems	O
—	O
an	O
early	O
implementation	O
of	O
distributed	B-Architecture
computing	I-Architecture
.	O
</s>
<s>
Pike	O
wrote	O
two	O
window	O
systems	O
for	O
the	O
Blit	B-Algorithm
,	O
mpx	O
for	O
8th	O
Edition	O
Unix	B-Application
and	O
mux	O
for	O
9th	O
Edition	O
,	O
both	O
sporting	O
a	O
minimalistic	O
design	O
.	O
</s>
<s>
The	O
design	O
of	O
these	O
influenced	O
the	O
later	O
Plan	B-Operating_System
9	I-Operating_System
window	O
systems	O
8½	B-Application
and	O
rio	B-Language
.	O
</s>
<s>
When	O
the	O
Blit	B-Algorithm
was	O
commercialized	O
as	O
the	O
DMD	O
5620	O
,	O
a	O
variant	O
of	O
mpx	O
called	O
"	O
layers	O
"	O
was	O
added	O
to	O
SVR3	O
.	O
</s>
<s>
9front	B-Operating_System
(	O
a	O
Plan	B-Operating_System
9	I-Operating_System
fork	O
)	O
contains	O
a	O
Blit	B-Algorithm
emulator	O
that	O
runs	O
its	O
original	O
firmware	O
,	O
which	O
can	O
be	O
used	O
with	O
mux	O
(	O
available	O
in	O
recently	O
released	O
Research	B-Operating_System
Unix	I-Operating_System
v8	O
)	O
.	O
</s>
