<s>
The	O
VIC-20	B-Device
(	O
known	O
as	O
the	O
VC-20	B-Device
in	O
Germany	O
and	O
the	O
VIC-1001	B-Device
in	O
Japan	O
)	O
is	O
an	O
8-bit	O
home	O
computer	O
that	O
was	O
sold	O
by	O
Commodore	O
Business	O
Machines	O
.	O
</s>
<s>
The	O
VIC-20	B-Device
was	O
announced	O
in	O
1980	O
,	O
roughly	O
three	O
years	O
after	O
Commodore	O
's	O
first	O
personal	B-Device
computer	I-Device
,	O
the	O
PET	B-Device
.	O
</s>
<s>
The	O
VIC-20	B-Device
was	O
the	O
first	O
computer	O
of	O
any	O
description	O
to	O
sell	O
one	O
million	O
units	O
.	O
</s>
<s>
As	O
the	O
Apple	B-Device
II	I-Device
gained	O
momentum	O
with	O
the	O
advent	O
of	O
VisiCalc	B-Application
in	O
1979	O
,	O
Jack	O
Tramiel	O
wanted	O
a	O
product	O
that	O
would	O
compete	O
in	O
the	O
same	O
segment	O
,	O
to	O
be	O
presented	O
at	O
the	O
January	O
1980	O
CES	O
.	O
</s>
<s>
However	O
,	O
the	O
chip	O
could	O
not	O
be	O
used	O
in	O
the	O
TOI	O
since	O
it	O
required	O
very	O
expensive	O
static	B-Architecture
RAM	I-Architecture
to	O
operate	O
fast	O
enough	O
.	O
</s>
<s>
Radio	O
Shack	O
had	O
been	O
achieving	O
considerable	O
success	O
with	O
the	O
TRS-80	B-Device
Model	I-Device
I	I-Device
,	O
a	O
relatively	O
low-cost	O
machine	O
that	O
was	O
widely	O
sold	O
to	O
novices	O
and	O
in	O
1980	O
released	O
the	O
Color	B-Device
Computer	I-Device
,	O
which	O
was	O
aimed	O
at	O
the	O
home	O
and	O
educational	O
markets	O
,	O
used	O
ROM	B-Protocol
cartridges	I-Protocol
for	O
software	O
,	O
and	O
connected	O
to	O
a	O
TV	O
set	O
.	O
</s>
<s>
The	O
parts	O
contributed	O
by	O
Russell	O
included	O
a	O
port	O
of	O
the	O
operating	O
system	O
(	O
kernel	O
and	O
BASIC	B-Language
interpreter	O
)	O
taken	O
from	O
John	O
Feagans	O
design	O
for	O
the	O
Commodore	B-Device
PET	I-Device
,	O
a	O
character	O
set	O
with	O
the	O
characteristic	O
PETSCII	B-Protocol
,	O
an	O
Atari	O
CX40	O
joystick-compatible	O
interface	O
,	O
and	O
a	O
ROM	B-Protocol
cartridge	I-Protocol
port	O
.	O
</s>
<s>
The	O
serial	O
IEEE-488-derivative	O
CBM-488	B-Protocol
interface	O
was	O
designed	O
by	O
Glen	O
Stark	O
.	O
</s>
<s>
It	O
served	O
several	O
purposes	O
,	O
including	O
costing	O
substantially	O
less	O
than	O
the	O
IEEE-488	O
interface	O
on	O
the	O
PET	B-Device
,	O
using	O
smaller	O
cables	O
and	O
connectors	O
that	O
allowed	O
for	O
a	O
more	O
compact	O
case	O
design	O
,	O
and	O
also	O
complying	O
with	O
newly	O
imposed	O
FCC	O
regulations	O
on	O
RFI	O
emissions	O
by	O
home	O
electronics	O
(	O
the	O
PET	B-Device
was	O
certified	O
as	O
Class	O
B	O
office	O
equipment	O
which	O
had	O
less	O
stringent	O
RFI	O
requirements	O
)	O
.	O
</s>
<s>
Altogether	O
,	O
the	O
VIC	B-Device
20	I-Device
development	O
team	O
consisted	O
of	O
five	O
people	O
led	O
by	O
Michael	O
Tomczyk	O
,	O
the	O
product	O
manager	O
who	O
recruited	O
the	O
group	O
and	O
dubbed	O
them	O
the	O
VIC	B-General_Concept
Commandos	O
.	O
</s>
<s>
Commodore	O
founder	O
Jack	O
Tramiel	O
initially	O
gave	O
Tomczyk	O
the	O
title	O
VIC	B-General_Concept
Czar	O
and	O
later	O
appointed	O
him	O
product	O
manager	O
.	O
</s>
<s>
Tomczyk	O
insisted	O
on	O
several	O
features	O
including	O
full-size	O
typewriter	O
keys	O
,	O
programmable	O
function	B-Application
keys	I-Application
,	O
and	O
a	O
built-in	O
RS-232	O
interface	O
.	O
</s>
<s>
Michael	O
later	O
contracted	O
and	O
co-designed	O
a	O
$100	O
modem	B-Application
,	O
the	O
VICModem	O
,	O
which	O
became	O
the	O
first	O
modem	B-Application
to	O
sell	O
1	O
million	O
units	O
.	O
</s>
<s>
At	O
the	O
time	O
,	O
Commodore	O
had	O
a	O
glut	O
of	O
SRAM	B-Architecture
chips	O
,	O
so	O
Tramiel	O
decided	O
these	O
should	O
be	O
used	O
in	O
the	O
new	O
computer	O
.	O
</s>
<s>
The	O
result	O
was	O
arguably	O
closer	O
to	O
the	O
PET	B-Device
or	O
TOI	O
computers	O
than	O
to	O
Yannes	O
 '	O
prototype	O
,	O
albeit	O
with	O
a	O
22-column	O
VIC	B-General_Concept
chip	I-General_Concept
instead	O
of	O
the	O
custom	O
chips	O
designed	O
for	O
the	O
more	O
ambitious	O
computers	O
.	O
</s>
<s>
As	O
the	O
amount	O
of	O
memory	O
on	O
the	O
VIC-20	B-Device
'	O
s	O
system	O
board	O
was	O
very	O
small	O
even	O
for	O
1981	O
standards	O
,	O
the	O
design	O
team	O
could	O
get	O
away	O
with	O
using	O
more	O
expensive	O
SRAM	B-Architecture
due	O
to	O
its	O
lower	O
power	O
consumption	O
,	O
heat	O
output	O
,	O
and	O
less	O
supporting	O
circuitry	O
.	O
</s>
<s>
The	O
original	O
Revision	O
A	O
system	O
board	O
found	O
in	O
all	O
silver-label	O
VIC-20s	B-Device
used	O
2114	O
SRAMs	O
and	O
due	O
to	O
their	O
tiny	O
size	O
(	O
only	O
512	O
bytes	B-Application
per	O
chip	O
)	O
,	O
ten	O
of	O
them	O
were	O
required	O
to	O
reach	O
5KB	O
of	O
system	O
RAM	B-Architecture
.	O
</s>
<s>
The	O
Revision	O
B	O
system	O
board	O
,	O
found	O
in	O
rainbow	O
logo	O
VIC-20s	B-Device
(	O
see	O
below	O
)	O
switched	O
to	O
larger	O
2048-byte	O
SRAMs	O
which	O
reduced	O
the	O
memory	O
count	O
to	O
five	O
chips	O
:	O
2×	O
2048-byte	O
chips	O
+	O
3×	O
2114	O
(	O
the	O
1024	O
×	O
4	O
bits	O
)	O
chips	O
.	O
</s>
<s>
In	O
April	O
1980	O
,	O
at	O
a	O
meeting	O
of	O
general	O
managers	O
outside	O
London	O
,	O
Jack	O
Tramiel	O
declared	O
he	O
wanted	O
a	O
low-cost	O
color	B-Device
computer	I-Device
.	O
</s>
<s>
The	O
VIC-20	B-Device
was	O
marketed	O
in	O
Japan	O
as	O
VIC-1001	B-Device
before	O
VIC-20	B-Device
was	O
introduced	O
to	O
the	O
US	O
.	O
</s>
<s>
Recommendations	O
included	O
programmable	O
function	B-Application
keys	I-Application
(	O
inspired	O
by	O
competing	O
Japanese	O
computers	O
)	O
,	O
full-size	O
typewriter-style	O
keys	O
,	O
and	O
built-in	O
RS-232	O
.	O
</s>
<s>
With	O
help	O
from	O
a	O
Commodore	O
engineer	O
who	O
came	O
to	O
Longwood	O
,	O
Florida	O
,	O
to	O
assist	O
in	O
the	O
effort	O
,	O
five	O
of	O
Adams	O
's	O
Adventure	O
International	O
game	O
series	O
were	O
ported	O
to	O
the	O
VIC	B-General_Concept
.	O
</s>
<s>
They	O
got	O
around	O
the	O
limited	O
memory	O
of	O
VIC-20	B-Device
by	O
having	O
the	O
games	O
reside	O
in	O
a	O
ROM	B-Protocol
cartridge	I-Protocol
instead	O
of	O
being	O
loaded	O
into	O
main	O
memory	O
via	O
cassette	O
as	O
they	O
were	O
on	O
the	O
TRS-80	B-Device
and	O
other	O
machines	O
.	O
</s>
<s>
The	O
first	O
production	O
run	O
of	O
the	O
five	O
cartridges	B-Protocol
generated	O
over	O
$	O
1,500,000	O
in	O
sales	O
for	O
Commodore	O
.	O
</s>
<s>
The	O
VIC-20	B-Device
went	O
through	O
several	O
variations	O
in	O
its	O
three-and-a-half	O
years	O
of	O
production	O
.	O
</s>
<s>
First-year	O
models	O
(	O
1980	O
)	O
had	O
a	O
PET-style	O
keyboard	O
with	O
a	O
blocky	O
typeface	O
while	O
most	O
VIC-20s	B-Device
made	O
during	O
1981	O
had	O
a	O
slightly	O
different	O
keyboard	O
also	O
shared	O
with	O
early	O
C64s	O
.	O
</s>
<s>
The	O
rainbow	O
logo	O
VIC-20	B-Device
was	O
introduced	O
in	O
early	O
1983	O
and	O
has	O
the	O
newer	O
C64	O
keyboard	O
with	O
gray	O
function	B-Application
keys	I-Application
and	O
the	O
Revision	O
B	O
motherboard	O
.	O
</s>
<s>
A	O
C64	O
"	O
black	O
brick	O
"	O
PSU	O
is	O
compatible	O
with	O
Revision	O
B	O
VIC-20s	B-Device
;	O
however	O
,	O
the	O
VIC	B-General_Concept
's	O
PSU	O
is	O
not	O
recommended	O
on	O
a	O
C64	O
if	O
any	O
external	O
devices	O
,	O
such	O
as	O
cartridges	B-Protocol
or	O
user	O
port	O
accessories	O
,	O
are	O
installed	O
,	O
as	O
it	O
will	O
overdraw	O
the	O
available	O
power	O
.	O
</s>
<s>
Older	O
Revision	O
A	O
VIC-20s	B-Device
cannot	O
use	O
a	O
C64	O
PSU	O
or	O
vice	O
versa	O
as	O
their	O
power	O
requirement	O
is	O
too	O
high	O
.	O
</s>
<s>
The	O
VIC-20	B-Device
was	O
a	O
bestseller	O
,	O
becoming	O
the	O
first	O
computer	O
to	O
sell	O
over	O
a	O
million	O
.	O
</s>
<s>
In	O
summer	O
1982	O
,	O
Commodore	O
unveiled	O
the	O
a	O
more	O
advanced	O
machine	O
with	O
of	O
RAM	B-Architecture
and	O
considerably	O
improved	O
sound	O
and	O
graphics	O
.	O
</s>
<s>
The	O
VIC-20	B-Device
was	O
widely	O
available	O
for	O
under	O
$90	O
by	O
that	O
time	O
.	O
</s>
<s>
Commodore	O
discontinued	O
the	O
VIC-20	B-Device
in	O
January	O
1985	O
.	O
</s>
<s>
Perhaps	O
the	O
last	O
new	O
commercially	O
available	O
VIC-20	B-Device
peripheral	O
was	O
the	O
VIC-Talker	O
,	O
a	O
speech	B-Application
synthesizer	I-Application
.	O
</s>
<s>
wrote	O
in	O
January	O
1986	O
,	O
"	O
Believe	O
it	O
or	O
not	O
,	O
a	O
new	O
VIC	B-General_Concept
accessory	O
...	O
We	O
were	O
as	O
surprised	O
as	O
you.	O
"	O
</s>
<s>
The	O
VIC-20	B-Device
was	O
intended	O
to	O
be	O
more	O
economical	O
than	O
the	O
PET	B-Device
computer	I-Device
.	O
</s>
<s>
It	O
was	O
equipped	O
with	O
5KB	O
of	O
static	B-Architecture
RAM	I-Architecture
and	O
used	O
the	O
same	O
MOS	B-General_Concept
6502	I-General_Concept
CPU	B-General_Concept
as	O
the	O
PET	B-Device
.	O
</s>
<s>
The	O
VIC-20	B-Device
'	O
s	O
video	O
chip	O
,	O
the	O
MOS	B-General_Concept
Technology	I-General_Concept
VIC	I-General_Concept
,	O
was	O
a	O
general-purpose	O
color	O
video	O
chip	O
designed	O
by	O
Al	O
Charpentier	O
in	O
1977	O
and	O
intended	O
for	O
use	O
in	O
inexpensive	O
display	O
terminals	O
and	O
game	O
consoles	O
,	O
but	O
Commodore	O
could	O
not	O
find	O
a	O
market	O
for	O
the	O
chip	O
.	O
</s>
<s>
While	O
newer	O
PETs	O
had	O
the	O
upgraded	O
BASIC	B-Language
4.0	O
,	O
with	O
disk	O
commands	O
and	O
improved	O
garbage	O
collection	O
,	O
the	O
VIC-20	B-Device
reverted	O
to	O
the	O
8KB	O
BASIC	B-Language
2.0	I-Language
used	O
on	O
earlier	O
PETs	O
as	O
part	O
of	O
another	O
of	O
the	O
design	O
team	O
's	O
goals	O
:	O
20KB	O
system	O
ROMs	O
.	O
</s>
<s>
The	O
VIC-20	B-Device
has	O
a	O
composite	O
output	O
,	O
which	O
provides	O
a	O
sharper	O
,	O
cleaner	O
picture	O
if	O
a	O
dedicated	O
monitor	O
is	O
used	O
.	O
</s>
<s>
The	O
TRS-80	B-Device
Color	I-Device
Computer	I-Device
and	O
Atari	O
400	O
have	O
only	O
RF	O
video	O
output	O
.	O
</s>
<s>
The	O
"	O
20	O
"	O
in	O
the	O
computer	O
's	O
name	O
was	O
widely	O
assumed	O
to	O
refer	O
to	O
the	O
text	O
width	O
of	O
the	O
screen	O
(	O
although	O
in	O
fact	O
,	O
the	O
VIC-20	B-Device
has	O
22-column	O
text	O
,	O
not	O
20	O
)	O
or	O
that	O
it	O
referred	O
to	O
the	O
combined	O
size	O
of	O
the	O
system	O
ROMs	O
(	O
8KB	O
BASIC+8KB	O
KERNAL+4KB	O
character	O
ROM	B-Device
)	O
.	O
</s>
<s>
I	O
felt	O
it	O
balanced	O
things	O
out	O
a	O
bit	O
since	O
'	O
Vic	B-General_Concept
 '	O
sounded	O
like	O
the	O
name	O
of	O
a	O
truck	O
driver.	O
"	O
</s>
<s>
The	O
graphics	O
capabilities	O
of	O
the	O
VIC	B-General_Concept
chip	I-General_Concept
(	O
6560/6561	O
)	O
are	O
limited	O
but	O
flexible	O
.	O
</s>
<s>
Since	O
a	O
PAL	O
or	O
NTSC	O
screen	O
has	O
a	O
4:3	O
width-to-height	O
ratio	O
,	O
each	O
VIC	B-General_Concept
pixel	O
is	O
much	O
wider	O
than	O
it	O
is	O
high	O
.	O
</s>
<s>
Just	O
as	O
on	O
the	O
PET	B-Device
,	O
two	O
different	O
256-character	O
sets	O
are	O
included	O
,	O
the	O
uppercase/graphics	O
character	O
set	O
and	O
the	O
upper/lowercase	O
set	O
,	O
and	O
reverse	O
video	O
versions	O
of	O
both	O
.	O
</s>
<s>
Normally	O
,	O
the	O
VIC-20	B-Device
operates	O
in	O
a	O
high-resolution	O
mode	O
whereby	O
each	O
character	O
is	O
8×8	O
pixels	O
in	O
size	O
and	O
uses	O
one	O
color	O
.	O
</s>
<s>
The	O
VIC	B-General_Concept
chip	I-General_Concept
does	O
not	O
support	O
a	O
true	O
bitmap	O
mode	O
,	O
but	O
programmers	O
can	O
define	O
their	O
own	O
custom	O
character	O
sets	O
.	O
</s>
<s>
It	O
is	O
possible	O
to	O
get	O
a	O
fully	O
addressable	O
screen	O
,	O
although	O
slightly	O
smaller	O
than	O
normal	O
,	O
by	O
filling	O
the	O
screen	O
with	O
a	O
sequence	O
of	O
different	O
double-height	O
characters	O
,	O
then	O
turning	O
on	O
the	O
pixels	O
selectively	O
inside	O
the	O
RAM-based	O
character	O
definitions	O
.	O
</s>
<s>
The	O
Super	B-Language
Expander	I-Language
cartridge	B-Protocol
adds	O
BASIC	B-Language
commands	O
supporting	O
such	O
a	O
graphics	O
mode	O
using	O
a	O
resolution	O
of	O
160×160	O
pixels	O
.	O
</s>
<s>
This	O
is	O
used	O
by	O
the	O
port	O
of	O
Omega	B-Application
Race	I-Application
.	O
</s>
<s>
The	O
VIC	B-General_Concept
chip	I-General_Concept
has	O
readable	O
scan-line	B-Algorithm
counters	O
but	O
cannot	O
generate	O
interrupts	B-Application
based	O
on	O
the	O
scan	O
position	O
.	O
</s>
<s>
The	O
VIC	B-General_Concept
chip	I-General_Concept
can	O
process	O
a	O
light	B-Device
pen	I-Device
signal	O
via	O
the	O
joystick	B-Device
port	O
,	O
but	O
few	O
appeared	O
on	O
the	O
market	O
.	O
</s>
<s>
The	O
VIC	B-General_Concept
chip	I-General_Concept
outputs	O
Luma+Sync	O
and	O
Chroma	O
video	O
signals	O
,	O
which	O
are	O
combined	O
to	O
create	O
the	O
VIC-20	B-Device
'	O
s	O
composite	O
video	O
output	O
.	O
</s>
<s>
The	O
VIC	B-General_Concept
chip	I-General_Concept
has	O
three	O
pulse	O
wave	O
generators	O
and	O
a	O
white	O
noise	O
generator	O
with	O
overall	O
volume	O
control	O
and	O
mono	O
output	O
.	O
</s>
<s>
Each	O
pulse	O
wave	O
generator	O
has	O
a	O
range	O
of	O
three	O
octaves	B-Language
located	O
on	O
the	O
scale	O
about	O
an	O
octave	B-Language
apart	O
,	O
giving	O
a	O
total	O
range	O
of	O
about	O
five	O
octaves	B-Language
.	O
</s>
<s>
The	O
VIC-20	B-Device
shipped	O
with	O
RAM	B-Architecture
,	O
but	O
of	O
this	O
is	O
used	O
for	O
the	O
video	O
display	O
and	O
dynamic	O
aspects	O
of	O
the	O
ROM-resident	O
Commodore	B-Language
BASIC	I-Language
and	O
KERNAL	B-Operating_System
(	O
a	O
low-level	O
operating	O
system	O
)	O
.	O
</s>
<s>
Only	O
3,583	O
bytes	B-Application
of	O
BASIC	B-Language
program	B-Device
memory	I-Device
for	O
code	O
and	O
variables	O
are	O
actually	O
available	O
on	O
an	O
unexpanded	O
machine	O
.	O
</s>
<s>
Unlike	O
the	O
PET	B-Device
,	O
the	O
VIC-20	B-Device
does	O
not	O
include	O
a	O
machine	B-General_Concept
language	I-General_Concept
monitor	I-General_Concept
,	O
but	O
Commodore	O
offered	O
them	O
on	O
disk	O
,	O
tape	O
,	O
or	O
cartridge	B-Protocol
,	O
with	O
several	O
different	O
executables	B-Application
to	O
load	O
into	O
various	O
memory	O
locations	O
.	O
</s>
<s>
The	O
monitor	O
programs	O
were	O
the	O
same	O
as	O
the	O
PET	B-Device
monitor	O
but	O
added	O
a	O
mini-assembler	O
instead	O
of	O
requiring	O
the	O
user	O
to	O
enter	O
hexadecimal	O
opcodes	B-Language
.	O
</s>
<s>
RAM	B-Architecture
expansion	O
cartridges	B-Protocol
ultimately	O
allowed	O
adding	O
up	O
to	O
to	O
the	O
BASIC	B-Language
user	O
memory	O
;	O
together	O
with	O
the	O
built-in	O
user	O
memory	O
,	O
this	O
gave	O
a	O
maximum	O
of	O
for	O
BASIC	B-Language
programs	O
and	O
variables	O
.	O
</s>
<s>
Memory	O
not	O
visible	O
to	O
BASIC	B-Language
could	O
still	O
be	O
used	O
by	O
machine	O
code	O
programs	O
.	O
</s>
<s>
+	O
Memory	B-General_Concept
map	I-General_Concept
Address(hexadecimal )	O
Size[ in	O
KB ]	O
Description	O
Cartridgedecoded	O
1.0	O
RAM	B-Architecture
with	O
jump	O
vectors	O
etc	O
.	O
</s>
<s>
The	O
VIC-20	B-Device
has	O
card	O
edge	O
connectors	O
for	O
program/expansion	O
cartridges	B-Protocol
and	O
a	O
PET-standard	O
Datassette	B-Device
tape	O
drive	O
.	O
</s>
<s>
The	O
VIC-20	B-Device
did	O
not	O
originally	O
have	O
a	O
disk	O
drive	O
;	O
the	O
VIC-1540	B-Device
disk	O
drive	O
was	O
released	O
in	O
1981	O
.	O
</s>
<s>
There	O
is	O
one	O
Atari	B-Protocol
joystick	I-Protocol
port	I-Protocol
,	O
compatible	O
with	O
the	O
digital	O
joysticks	B-Device
and	O
paddles	B-Device
used	O
with	O
Atari	B-General_Concept
VCS	I-General_Concept
and	O
Atari	B-Device
8-bit	I-Device
family	I-Device
;	O
a	O
serial	O
CBM-488	B-Protocol
bus	O
(	O
a	O
serial	O
version	O
of	O
the	O
PET	B-Device
's	O
IEEE-488	O
bus	O
)	O
for	O
daisy	O
chaining	O
disk	B-Device
drives	I-Device
and	O
printers	O
;	O
a	O
TTL-level	O
"	O
user	O
port	O
"	O
with	O
both	O
RS-232	O
and	O
Centronics	O
signals	O
(	O
most	O
frequently	O
used	O
as	O
RS-232	O
,	O
for	O
connecting	O
a	O
modem	B-Application
)	O
.	O
</s>
<s>
The	O
VIC	B-General_Concept
has	O
a	O
ROM	B-Protocol
cartridge	I-Protocol
port	O
for	O
games	O
and	O
other	O
software	O
as	O
well	O
as	O
for	O
adding	O
memory	O
to	O
the	O
machine	O
.	O
</s>
<s>
Port	O
expander	O
boxes	O
from	O
Commodore	O
and	O
other	O
vendors	O
allow	O
more	O
than	O
one	O
cartridge	B-Protocol
to	O
be	O
attached	O
at	O
a	O
time	O
.	O
</s>
<s>
Cartridge	B-Protocol
size	O
ranges	O
from	O
in	O
size	O
,	O
although	O
the	O
latter	O
was	O
uncommon	O
due	O
to	O
its	O
cost	O
.	O
</s>
<s>
The	O
VIC-20	B-Device
can	O
be	O
hooked	O
into	O
external	O
electronic	O
circuitry	O
via	O
the	O
joystick	B-Device
port	O
,	O
the	O
"	O
user	O
port	O
,	O
"	O
or	O
the	O
memory	O
expansion	O
cartridge	B-Protocol
port	O
,	O
which	O
exposes	O
various	O
analog	O
to	O
digital	O
,	O
memory	O
bus	O
,	O
and	O
other	O
internal	O
I/O	O
circuits	O
to	O
the	O
experimenter	O
.	O
</s>
<s>
PEEK	B-Language
and	I-Language
POKE	I-Language
commands	O
from	O
BASIC	B-Language
can	O
be	O
used	O
to	O
perform	O
data	O
acquisition	O
from	O
temperature	O
sensors	O
,	O
control	O
robotic	O
stepper	O
motors	O
,	O
etc	O
.	O
</s>
<s>
In	O
1981	O
,	O
Tomczyk	O
contracted	O
with	O
an	O
outside	O
engineering	O
group	O
to	O
develop	O
a	O
direct-connect	O
modem-on-a-cartridge	O
(	O
the	O
VICModem	O
)	O
,	O
which	O
at	O
US$99	O
became	O
the	O
first	O
modem	B-Application
priced	O
under	O
US$100	O
.	O
</s>
<s>
The	O
VICModem	O
was	O
also	O
the	O
first	O
modem	B-Application
to	O
sell	O
over	O
1	O
million	O
units	O
.	O
</s>
<s>
The	O
VIC-20	B-Device
'	O
s	O
RAM	B-Architecture
is	O
expandable	O
through	O
the	O
cartridge	B-Protocol
port	O
via	O
a	O
RAM	B-Architecture
cartridge	B-Protocol
.	O
</s>
<s>
RAM	B-Architecture
cartridges	B-Protocol
were	O
available	O
from	O
Commodore	O
in	O
several	O
sizes	O
:	O
(	O
with	O
or	O
without	O
an	O
included	O
"	O
Super	B-Language
Expander	I-Language
"	O
BASIC	B-Language
extension	O
ROM	B-Device
)	O
,	O
,	O
and	O
.	O
</s>
<s>
Third-party	O
vendors	O
eventually	O
offered	O
expansion	O
cartridges	B-Protocol
with	O
larger	O
RAM	B-Architecture
sizes	O
.	O
</s>
<s>
The	O
internal	O
memory	B-General_Concept
map	I-General_Concept
is	O
reorganized	O
if	O
you	O
plug	O
in	O
and	O
cartridges	B-Protocol
,	O
leading	O
to	O
a	O
situation	O
where	O
some	O
programs	O
only	O
work	O
if	O
the	O
right	O
amount	O
of	O
memory	O
is	O
present	O
(	O
the	O
most	O
significant	O
divide	O
being	O
between	O
a	O
machine	O
with	O
no	O
or	O
extra	O
memory	O
on	O
one	O
hand	O
,	O
and	O
a	O
machine	O
with	O
more	O
extra	O
memory	O
on	O
the	O
other	O
)	O
.	O
</s>
<s>
Most	O
expansion	O
cartridges	B-Protocol
featured	O
hardware	O
DIP	O
switches	O
,	O
allowing	O
the	O
RAM	B-Architecture
to	O
be	O
enabled	O
in	O
user-selectable	O
memory	O
blocks	O
.	O
</s>
<s>
Since	O
the	O
VIC-20	B-Device
was	O
designed	O
to	O
use	O
SRAM	B-Architecture
rather	O
than	O
DRAM	O
,	O
the	O
system	O
board	O
has	O
no	O
provisions	O
for	O
DRAM	O
refresh	O
.	O
</s>
<s>
The	O
VIC-20	B-Device
'	O
s	O
BASIC	B-Language
is	O
compatible	O
with	O
the	O
PET	B-Device
's	O
,	O
and	O
the	O
Datasette	B-Device
format	O
is	O
the	O
same	O
.	O
</s>
<s>
favorably	O
contrasted	O
the	O
company	O
's	O
encouragement	O
of	O
"	O
cottage	O
industry	O
software	O
developers	O
"	O
to	O
Texas	O
Instruments	O
discouraging	O
third-party	B-General_Concept
software	I-General_Concept
.	O
</s>
<s>
Because	O
of	O
its	O
small	O
memory	O
and	O
low-resolution	O
display	O
compared	O
to	O
some	O
other	O
computers	O
of	O
the	O
time	O
,	O
the	O
VIC-20	B-Device
was	O
primarily	O
used	O
for	O
educational	O
software	O
and	O
games	O
.	O
</s>
<s>
The	O
VIC	B-General_Concept
had	O
a	O
sizable	O
library	O
of	O
public	O
domain	O
and	O
freeware	B-License
software	I-License
.	O
</s>
<s>
Several	O
computer	O
magazines	O
sold	O
on	O
newsstands	O
,	O
such	O
as	O
Compute	O
!,	O
Family	O
Computing	O
,	O
RUN	O
,	O
Ahoy	O
!,	O
and	O
the	O
CBM-produced	O
Commodore	O
Power	O
Play	O
,	O
offered	O
programming	O
tips	O
and	O
type-in	O
programs	O
for	O
the	O
VIC-20	B-Device
.	O
</s>
<s>
An	O
estimated	O
300	O
commercial	O
titles	O
were	O
available	O
on	O
cartridge	B-Protocol
and	O
another	O
500+	O
were	O
available	O
on	O
tape	O
.	O
</s>
<s>
The	O
VIC	B-General_Concept
's	O
low	O
cost	O
led	O
to	O
it	O
being	O
used	O
by	O
the	O
Fort	O
Pierce	O
,	O
Florida	O
,	O
Utilities	O
Authority	O
to	O
measure	O
the	O
input	O
and	O
output	O
of	O
two	O
of	O
their	O
generators	O
and	O
display	O
the	O
results	O
on	O
monitors	O
throughout	O
the	O
plant	O
.	O
</s>
<s>
The	O
utility	O
was	O
able	O
to	O
purchase	O
multiple	O
VIC	B-General_Concept
and	O
C64	O
systems	O
for	O
the	O
cost	O
of	O
one	O
IBM	O
PC	O
compatible	O
.	O
</s>
<s>
While	O
the	O
PET	B-Device
was	O
sold	O
through	O
authorized	O
dealers	O
the	O
VIC-20	B-Device
primarily	O
sold	O
at	O
retail	O
,	O
especially	O
discount	O
and	O
toy	O
stores	O
,	O
where	O
it	O
could	O
compete	O
directly	O
with	O
game	O
consoles	O
.	O
</s>
<s>
The	O
VIC-20	B-Device
was	O
called	O
VC-20	B-Device
in	O
Germany	O
and	O
was	O
marketed	O
as	O
though	O
it	O
were	O
an	O
abbreviation	O
of	O
VolksComputer	O
(	O
"	O
people	O
's	O
computer	O
,	O
"	O
similar	O
to	O
Volkswagen	O
and	O
Volksempfänger	O
)	O
.	O
</s>
<s>
in	O
1981	O
expected	O
the	O
VIC-20	B-Device
would	O
be	O
popular	O
in	O
classrooms	O
and	O
homes	O
with	O
small	O
children	O
,	O
with	O
"	O
excellent	O
graphic	O
and	O
sound	O
capabilities	O
"	O
.	O
</s>
<s>
While	O
predicting	O
the	O
22-column	O
screen	O
was	O
"	O
too	O
small	O
to	O
support	O
any	O
but	O
the	O
most	O
rudimentary	O
business	O
applications	O
"	O
the	O
magazine	O
observed	O
that	O
"	O
at	O
a	O
price	O
of	O
,	O
that	O
is	O
hardly	O
the	O
point	O
"	O
,	O
stating	O
that	O
"	O
the	O
VIC	B-General_Concept
will	O
provide	O
very	O
stiff	O
competition	O
to	O
the	O
TRS-80	B-Device
Color	I-Device
Computer	I-Device
"	O
and	O
"	O
is	O
a	O
much	O
more	O
valuable	O
computer	O
literacy	O
tool	O
than	O
"	O
other	O
products	O
like	O
the	O
TRS-80	B-Device
Pocket	I-Device
Computer	I-Device
.	O
</s>
<s>
concluded	O
"	O
VIC	B-General_Concept
will	O
create	O
its	O
own	O
market	O
,	O
and	O
it	O
will	O
be	O
a	O
big	O
one	O
"	O
.	O
</s>
<s>
While	O
also	O
noting	O
the	O
small	O
screen	O
size	O
and	O
RAM	B-Architecture
,	O
BYTE	B-Application
stated	O
that	O
the	O
VIC	B-Device
20	I-Device
was	O
"	O
unexcelled	O
as	O
low-cost	O
,	O
consumer-oriented	O
computer	O
.	O
</s>
<s>
Even	O
with	O
some	O
of	O
its	O
limitations	O
...	O
it	O
makes	O
an	O
impressive	O
showing	O
against	O
...	O
the	O
Apple	B-Device
II	I-Device
,	O
the	O
Radio	B-Device
Shack	I-Device
TRS-80	I-Device
,	O
and	O
the	O
Atari	B-Device
800	I-Device
"	O
.	O
</s>
<s>
The	O
magazine	O
praised	O
the	O
price	O
(	O
"	O
Looking	O
at	O
a	O
picture	O
...	O
might	O
cause	O
you	O
to	O
think	O
would	O
be	O
a	O
fair	O
price	O
...	O
But	O
it	O
does	O
not	O
cost	O
—	O
the	O
VIC	B-Device
20	I-Device
retails	O
for	O
"	O
)	O
,	O
keyboard	O
(	O
"	O
the	O
equal	O
of	O
any	O
personal-computer	O
keyboard	O
in	O
both	O
appearance	O
and	O
performance	O
.	O
</s>
<s>
This	O
is	O
a	O
remarkable	O
achievement	O
,	O
almost	O
unbelievable	O
considering	O
the	O
price	O
of	O
the	O
entire	O
unit	O
"	O
)	O
,	O
graphics	O
,	O
documentation	O
,	O
and	O
ease	O
of	O
software	O
development	O
with	O
the	O
KERNAL	B-Operating_System
.	O
</s>
