<s>
Due	O
to	O
the	O
backwards	B-General_Concept
compatibility	I-General_Concept
of	O
the	O
Commodore	B-Device
128	I-Device
,	O
most	O
peripherals	O
will	O
work	O
on	O
that	O
system	O
,	O
as	O
well	O
.	O
</s>
<s>
There	O
's	O
some	O
compatibility	O
with	O
the	O
VIC-20	B-Device
and	O
PET	B-Device
too	O
.	O
</s>
<s>
In	O
the	O
United	O
States	O
,	O
the	O
1541	B-Device
floppy	B-Device
disk	I-Device
drive	I-Device
was	O
widespread	O
.	O
</s>
<s>
By	O
contrast	O
,	O
in	O
Europe	O
,	O
the	O
C64	O
was	O
often	O
used	O
with	O
cassette	O
tape	O
drives	O
(	O
Datasette	B-Device
)	O
,	O
which	O
were	O
much	O
cheaper	O
,	O
but	O
also	O
much	O
slower	O
than	O
floppy	B-Device
drives	I-Device
.	O
</s>
<s>
The	O
Datasette	B-Device
plugged	O
into	O
a	O
proprietary	O
edge	O
connector	O
on	O
the	O
Commodore	O
64	O
's	O
motherboard	B-Device
.	O
</s>
<s>
The	O
Datasette	B-Device
's	O
speed	O
was	O
very	O
slow	O
(	O
about	O
300	O
baud	O
)	O
.	O
</s>
<s>
Many	O
European	O
software	O
developers	O
wrote	O
their	O
own	O
fast	O
tape-loaders	O
which	O
replaced	O
the	O
internal	O
KERNAL	B-Operating_System
code	O
in	O
the	O
C64	O
and	O
offered	O
loading	O
times	O
more	O
comparable	O
to	O
disk	O
drive	O
speeds	O
.	O
</s>
<s>
One	O
such	O
minigame	O
fastloader	B-Device
is	O
Invade-a-Load	O
.	O
</s>
<s>
Also	O
,	O
not	O
too	O
dissimilar	O
to	O
floppy	B-Device
drive	I-Device
users	O
,	O
the	O
Datasette	B-Device
's	O
read	O
head	O
could	O
become	O
dirty	O
or	O
slip	O
out	O
of	O
alignment	O
.	O
</s>
<s>
A	O
small	O
screwdriver	O
could	O
be	O
used	O
to	O
align	O
the	O
tape	O
heads	O
,	O
and	O
a	O
few	O
companies	O
capitalized	O
by	O
selling	O
various	O
commercial	O
kits	O
for	O
Datasette	B-Device
head-alignment	O
tuning	O
.	O
</s>
<s>
As	O
the	O
Datasette	B-Device
lacked	O
any	O
random	O
read-write	O
access	O
,	O
users	O
had	O
to	O
either	O
wait	O
while	O
the	O
tape	O
ran	O
its	O
length	O
,	O
while	O
the	O
computer	O
printed	O
messages	O
like	O
"	O
SEARCHING	O
FOR	O
ALIEN	O
BOXING	O
...	O
FOUND	O
AFO	O
...	O
FOUND	O
SPACE	O
INVADERS	O
...	O
FOUND	O
MAN	O
...	O
FOUND	O
ALIEN	O
BOXING	O
...	O
LOADING	O
...	O
"	O
or	O
else	O
rely	O
on	O
a	O
tape	O
counter	O
number	O
to	O
find	O
the	O
starting	O
location	O
of	O
programs	O
on	O
cassette	O
.	O
</s>
<s>
Tape	O
counter	O
speeds	O
varied	O
over	O
different	O
datasette	B-Device
units	O
making	O
recorded	O
counter	O
numbers	O
unreliable	O
on	O
different	O
hardware	O
.	O
</s>
<s>
An	O
optional	O
streaming	B-Architecture
tape	O
drive	O
,	O
based	O
upon	O
the	O
QIC-02	B-Device
format	O
,	O
was	O
available	O
for	O
the	O
Xetec	B-Device
Lt	I-Device
.	I-Device
Kernal	I-Device
hard	B-Device
drive	I-Device
subsystem	O
(	O
see	O
below	O
)	O
.	O
</s>
<s>
A	O
similar	O
concept	O
to	O
the	O
ZX	B-Device
Microdrive	I-Device
was	O
the	O
extremely	O
fast	O
"	O
Phonemark	O
8500	O
Quick	B-Device
Data	I-Device
Drive	I-Device
"	O
which	O
has	O
capacity	O
using	O
a	O
micro-cassette	O
storage	O
unit	O
and	O
used	O
the	O
C2N	O
Datasette	B-Device
.	O
</s>
<s>
The	O
concept	O
eventually	O
succumbed	O
to	O
floppy	B-Device
drives	I-Device
.	O
</s>
<s>
The	O
Quick	B-Device
Data	I-Device
Drive	I-Device
(	O
QDD	O
)	O
connected	O
to	O
the	O
datassette	B-Device
port	O
of	O
the	O
Commodore	O
64	O
and	O
could	O
load	O
data	O
at	O
which	O
is	O
faster	O
than	O
the	O
C1541	B-Device
floppy	B-Device
drive	I-Device
.	O
</s>
<s>
It	O
could	O
also	O
be	O
daisy	O
chained	O
and	O
worked	O
with	O
the	O
VIC-20	B-Device
computer	O
as	O
well	O
.	O
</s>
<s>
The	O
Rotronics	B-Device
Wafadrive	I-Device
used	O
same	O
drive	O
mechanism	O
,	O
manufactured	O
by	O
BSR	O
.	O
</s>
<s>
Backup	B-Protocol
to	O
VHS	O
tapes	O
were	O
offered	O
by	O
DC	O
Electronics	O
with	O
their	O
cartridge	O
WHIZZARD	O
in	O
1988	O
.	O
</s>
<s>
Although	O
usually	O
not	O
supplied	O
with	O
the	O
machine	O
,	O
floppy	B-Device
disk	I-Device
drives	I-Device
of	O
the	O
5	O
inch	O
(	O
1541	B-Device
,	O
1570	B-Device
and	O
1571	B-Device
)	O
and	O
,	O
later	O
,	O
3	O
inch	O
(	O
1581	O
)	O
variety	O
were	O
available	O
from	O
Commodore	O
.	O
</s>
<s>
The	O
1541	B-Device
was	O
the	O
standard	O
floppy	B-Device
disk	I-Device
drive	I-Device
for	O
the	O
Commodore	O
64	O
,	O
with	O
nearly	O
all	O
disk-based	O
software	O
programs	O
released	O
for	O
the	O
computer	O
being	O
distributed	O
in	O
the	O
1541	B-Device
compatible	O
floppy	B-Device
disk	I-Device
format	O
.	O
</s>
<s>
The	O
1541	B-Device
was	O
very	O
slow	O
in	O
loading	O
programs	O
because	O
of	O
a	O
poorly	O
implemented	O
serial	B-Protocol
bus	I-Protocol
,	O
a	O
legacy	O
of	O
the	O
VIC-20	B-Device
.	O
</s>
<s>
The	O
1541	B-Device
disk	O
drive	O
was	O
notorious	O
for	O
not	O
only	O
its	O
slow	O
performance	O
and	O
large	O
physical	O
size	O
compared	O
to	O
the	O
C64	O
(	O
the	O
drive	O
is	O
almost	O
as	O
deep	O
as	O
the	O
computer	O
is	O
wide	O
)	O
,	O
but	O
also	O
for	O
the	O
drive	O
mechanisms	O
installed	O
during	O
early	O
production	O
runs	O
,	O
which	O
quickly	O
gained	O
a	O
bad	O
reputation	O
for	O
their	O
mechanical	O
unreliability	O
.	O
</s>
<s>
Due	O
to	O
lack	O
of	O
hardware	O
support	O
for	O
detecting	O
track	O
zero	O
position	O
,	O
Commodore	B-Device
DOS	I-Device
formatting	O
routines	O
and	O
many	O
complex	O
software	O
copy-protection	B-Application
schemes	O
(	O
which	O
used	O
data	O
stored	O
on	O
nonstandard	O
tracks	O
on	O
floppies	B-Device
)	O
had	O
to	O
rely	O
on	O
moving	O
the	O
head	O
specified	O
number	O
of	O
steps	O
in	O
order	O
to	O
make	O
sure	O
that	O
the	O
desired	O
head	O
position	O
for	O
formatting	O
or	O
reading	O
the	O
data	O
was	O
reached	O
.	O
</s>
<s>
Also	O
,	O
as	O
with	O
the	O
C64	O
,	O
1541	B-Device
drives	O
tended	O
to	O
overheat	O
due	O
to	O
a	O
design	O
that	O
did	O
not	O
permit	O
adequate	O
cooling	O
(	O
potentially	O
fixed	O
by	O
mounting	O
a	O
small	O
fan	O
to	O
the	O
case	O
)	O
.	O
</s>
<s>
Many	O
of	O
the	O
1541	B-Device
's	O
design	O
problems	O
were	O
eventually	O
rectified	O
in	O
Commodore	O
's	O
1541-II	O
disk	O
drive	O
,	O
which	O
was	O
compatible	O
with	O
the	O
older	O
units	O
.	O
</s>
<s>
The	O
power	O
supply	O
unit	O
was	O
not	O
housed	O
inside	O
the	O
drive	O
case	O
;	O
hence	O
,	O
the	O
1541-II	O
size	O
was	O
significantly	O
smaller	O
and	O
did	O
not	O
overheat	O
.	O
</s>
<s>
In	O
this	O
example	O
,	O
''	O
designates	O
the	O
last	O
program	O
loaded	O
,	O
or	O
the	O
first	O
program	O
on	O
the	O
disk	O
,	O
''	O
is	O
the	O
disk	O
drive	O
device	O
number	O
,	O
and	O
the	O
''	O
signifies	O
that	O
the	O
file	O
is	O
to	O
be	O
loaded	O
not	O
to	O
the	O
standard	O
memory	B-General_Concept
address	I-General_Concept
for	O
BASIC	O
programs	O
,	O
but	O
to	O
the	O
address	O
where	O
its	O
program	O
header	O
tells	O
it	O
to	O
go	O
—	O
the	O
address	O
it	O
was	O
saved	O
from	O
.	O
</s>
<s>
This	O
last	O
''	O
usually	O
signifies	O
a	O
machine	B-Language
language	I-Language
program	O
.	O
</s>
<s>
Not	O
long	O
after	O
the	O
1541	B-Device
's	O
introduction	O
,	O
third-party	O
developers	O
demonstrated	O
that	O
performance	O
could	O
be	O
improved	O
with	O
software	O
that	O
took	O
over	O
control	O
of	O
the	O
serial	B-Protocol
bus	I-Protocol
signal	O
lines	O
and	O
implemented	O
a	O
better	O
transfer	O
protocol	O
between	O
the	O
computer	O
and	O
disk	O
.	O
</s>
<s>
In	O
1984	O
Epyx	O
released	O
its	O
FastLoad	B-Application
cartridge	O
for	O
the	O
C64	O
,	O
which	O
replaced	O
some	O
of	O
the	O
1541	B-Device
's	O
slow	O
routines	O
with	O
its	O
own	O
custom	O
code	O
,	O
thus	O
allowing	O
users	O
to	O
load	O
programs	O
in	O
a	O
fraction	O
of	O
the	O
time	O
.	O
</s>
<s>
Despite	O
being	O
incompatible	O
with	O
many	O
programs	O
 '	O
copy	B-Application
protection	I-Application
schemes	O
,	O
the	O
cartridge	O
became	O
so	O
popular	O
among	O
grateful	O
C64	O
owners	O
(	O
likely	O
the	O
most-widespread	O
third-party	O
enhancement	O
for	O
the	O
C64	O
of	O
all	O
time	O
)	O
that	O
many	O
Commodore	O
dealers	O
sold	O
the	O
Epyx	O
cartridge	O
as	O
a	O
standard	O
item	O
when	O
selling	O
a	O
new	O
C64	O
with	O
the	O
1541	B-Device
.	O
</s>
<s>
As	O
a	O
free	O
alternative	O
to	O
FastLoad	B-Application
cartridges	O
,	O
numerous	O
pure	O
software	O
turbo-loader	O
programs	O
were	O
also	O
created	O
that	O
were	O
loaded	O
to	O
RAM	B-Architecture
each	O
time	O
after	O
the	O
computer	O
was	O
reset	O
.	O
</s>
<s>
The	O
best	O
of	O
these	O
turbo-loaders	O
were	O
able	O
to	O
accelerate	O
the	O
time	O
required	O
for	O
loading	O
a	O
program	O
from	O
the	O
floppy	B-Device
drive	I-Device
by	O
a	O
factor	O
of	O
20x	O
,	O
demonstrating	O
the	O
default	O
bus	O
implementation	O
's	O
inadequacy	O
.	O
</s>
<s>
As	O
turbo-loader	O
programs	O
were	O
relatively	O
small	O
,	O
it	O
was	O
common	O
to	O
place	O
one	O
on	O
almost	O
each	O
floppy	B-Device
disk	I-Device
so	O
that	O
it	O
could	O
be	O
quickly	O
loaded	O
to	O
RAM	B-Architecture
after	O
restart	O
.	O
</s>
<s>
The	O
1541	B-Device
floppy	B-Device
drive	I-Device
contained	O
a	O
MOS	B-General_Concept
6502	I-General_Concept
processor	O
acting	O
as	O
the	O
drive	O
controller	O
,	O
along	O
with	O
a	O
built-in	O
disk	B-Operating_System
operating	I-Operating_System
system	I-Operating_System
(	O
DOS	B-Operating_System
)	O
in	O
ROM	B-Device
and	O
a	O
small	O
amount	O
of	O
RAM	B-Architecture
,	O
the	O
latter	O
primarily	O
used	O
for	O
buffer	B-General_Concept
space	O
.	O
</s>
<s>
Since	O
this	O
arrangement	O
was	O
,	O
in	O
effect	O
,	O
a	O
specialized	O
computer	O
,	O
it	O
was	O
possible	O
to	O
write	O
custom	O
controller	O
routines	O
and	O
load	O
them	O
into	O
the	O
drive	O
's	O
RAM	B-Architecture
,	O
thus	O
making	O
the	O
drive	O
work	O
independently	O
of	O
the	O
C64	O
machine	O
.	O
</s>
<s>
For	O
example	O
,	O
certain	O
back	B-Protocol
up	I-Protocol
software	O
allowed	O
users	O
to	O
make	O
multiple	O
disk	O
copies	O
directly	O
between	O
daisy-chained	O
drives	O
without	O
a	O
C64	O
.	O
</s>
<s>
Outside	O
of	O
BBS	B-Application
operators	O
,	O
few	O
C64	O
owners	O
took	O
advantage	O
of	O
this	O
arrangement	O
and	O
the	O
accompanying	O
IEEE	O
devices	O
that	O
Commodore	O
sold	O
(	O
such	O
as	O
the	O
SFD-1001	B-Device
1-megabyte	O
5	O
inch	O
floppy	B-Device
disk	I-Device
drive	I-Device
,	O
and	O
the	O
peripherals	O
originally	O
made	O
for	O
the	O
IEEE	O
equipped	O
PET	B-Device
computers	I-Device
,	O
such	O
as	O
the	O
4040	O
and	O
8050	O
drives	O
and	O
the	O
9060/9090	B-Device
hard	B-Device
disk	I-Device
drives	I-Device
)	O
.	O
</s>
<s>
As	O
an	O
alternative	O
to	O
the	O
feeble	O
performing	O
1541	B-Device
or	O
the	O
relatively	O
expensive	O
IEEE	O
bus	O
adapter	O
and	O
associated	O
peripherals	O
,	O
a	O
number	O
of	O
third-party	O
serial-bus	O
drives	O
such	O
as	O
the	O
MSD	B-Device
Super	I-Device
Disk	I-Device
and	O
Indus	B-Device
GT	I-Device
appeared	O
that	O
often	O
offered	O
better	O
reliability	O
,	O
higher	O
performance	O
,	O
quieter	O
operation	O
,	O
or	O
simply	O
a	O
lower	O
price	O
than	O
the	O
1541	B-Device
,	O
although	O
often	O
at	O
the	O
expense	O
of	O
software	O
compatibility	O
due	O
to	O
the	O
difficulty	O
of	O
reverse	O
engineering	O
the	O
DOS	B-Operating_System
built	O
into	O
the	O
1541	B-Device
's	O
hardware	O
(	O
Commodore	O
's	O
IEEE-based	O
drives	O
faced	O
the	O
same	O
issue	O
due	O
to	O
the	O
dependence	O
of	O
the	O
DOS	B-Operating_System
on	O
features	O
of	O
the	O
Commodore	O
serial	B-Protocol
bus	I-Protocol
)	O
.	O
</s>
<s>
Like	O
the	O
IEEE-488	O
interface	O
,	O
the	O
CBM-bus	B-Protocol
offered	O
the	O
ability	O
to	O
daisy	B-Application
chain	I-Application
hardware	O
together	O
.	O
</s>
<s>
It	O
was	O
also	O
possible	O
,	O
without	O
requiring	O
a	O
VIC-switch	O
,	O
to	O
connect	O
two	O
Commodore	O
64s	O
to	O
one	O
1541	B-Device
floppy	B-Device
disk	I-Device
drive	I-Device
to	O
simulate	O
an	O
elementary	O
network	B-Architecture
,	O
allowing	O
the	O
two	O
computers	O
to	O
share	O
data	O
on	O
a	O
single	O
disk	O
(	O
if	O
the	O
two	O
computers	O
made	O
simultaneous	O
requests	O
,	O
the	O
1541	B-Device
handled	O
one	O
while	O
returning	O
an	O
error	O
to	O
the	O
other	O
,	O
which	O
surprised	O
many	O
people	O
who	O
expected	O
the	O
1541	B-Device
's	O
less-than-stellar	O
drive	O
controller	O
to	O
crash	B-General_Concept
or	O
hang	B-General_Concept
)	O
.	O
</s>
<s>
This	O
functionality	O
also	O
worked	O
with	O
a	O
mixed	O
combination	O
of	O
PET	B-Device
,	O
VIC-20	B-Device
,	O
and	O
other	O
selected	O
Commodore	O
8-bit	O
computers	O
.	O
</s>
<s>
In	O
the	O
mid-1980s	O
,	O
a	O
2.8-inch	O
floppy	O
disk	O
drive	O
,	O
the	O
Triton	B-Device
Disk	I-Device
Drive	I-Device
and	O
Controller	O
,	O
was	O
introduced	O
by	O
Radofin	O
Electronics	O
,	O
Ltd	O
.	O
</s>
<s>
It	O
was	O
compatible	O
with	O
the	O
Commodore	O
64	O
as	O
well	O
as	O
other	O
popular	O
home	O
computers	O
of	O
the	O
time	O
,	O
thanks	O
to	O
an	O
operating	O
system	O
stored	O
on	O
an	O
EPROM	B-General_Concept
on	O
an	O
external	O
controller	O
.	O
</s>
<s>
Up	O
to	O
20	O
files	O
could	O
be	O
kept	O
on	O
each	O
side	O
of	O
the	O
double-sided	O
floppy	B-Device
disks	I-Device
.	O
</s>
<s>
Later	O
in	O
the	O
1990s	O
,	O
Creative	O
Micro	O
Designs	O
produced	O
several	O
powerful	O
floppy	B-Device
disk	I-Device
drives	I-Device
for	O
the	O
Commodore	O
64	O
.	O
</s>
<s>
These	O
included	O
the	O
FD-Series	B-Device
serial	B-Protocol
bus	I-Protocol
compatible	O
3.5	O
″	O
floppy	B-Device
drives	I-Device
(	O
FD-2000	O
,	O
FD-4000	O
)	O
,	O
which	O
were	O
capable	O
of	O
emulating	O
Commodore	O
's	O
1581	O
3.5	O
″	O
drive	O
as	O
well	O
as	O
implementing	O
a	O
native	B-Language
mode	I-Language
partitioning	O
which	O
allowed	O
typical	O
3.5	O
″	O
high-density	O
floppy	B-Device
disks	I-Device
to	O
hold	O
1.6	O
MB	O
of	O
datamore	O
than	O
MS-DOS	B-Application
'	O
s	O
1.44	O
MB	O
format	O
.	O
</s>
<s>
The	O
FD-4000	O
drive	O
had	O
the	O
advantage	O
of	O
being	O
able	O
to	O
read	O
hard-to-find	O
enhanced	O
floppy	B-Device
disks	I-Device
and	O
could	O
be	O
formatted	O
to	O
hold	O
3.2	O
MB	O
of	O
data	O
.	O
</s>
<s>
In	O
addition	O
,	O
the	O
FD	B-Device
series	I-Device
drives	O
could	O
partition	O
floppy	B-Device
disks	I-Device
to	O
emulate	O
the	O
1541	B-Device
,	O
1571	B-Device
and	O
1581	O
disk	O
format	O
(	O
although	O
unfortunately	O
,	O
not	O
the	O
emulated	O
drive	O
firmware	O
)	O
,	O
and	O
a	O
real	O
time	O
clock	O
module	O
could	O
be	O
mounted	O
inside	O
the	O
drive	O
to	O
time-stamp	O
files	O
.	O
</s>
<s>
However	O
,	O
enthusiasts	O
could	O
use	O
this	O
drive	O
to	O
transfer	O
data	O
between	O
typical	O
PC	B-Application
MS-DOS	I-Application
and	O
the	O
Commodore	O
with	O
special	O
software	O
,	O
such	O
as	O
SOGWAP	O
's	O
Big	O
Blue	O
Reader	O
.	O
</s>
<s>
There	O
was	O
one	O
other	O
3.5	O
″	O
floppy	B-Device
drive	I-Device
available	O
for	O
the	O
Commodore	O
64	O
.	O
</s>
<s>
The	O
"	O
TIB	O
001	O
"	O
was	O
a	O
3.5	O
″	O
floppy	B-Device
drive	I-Device
that	O
connected	O
to	O
the	O
Commodore	O
64	O
via	O
the	O
expansion	O
port	O
,	O
meaning	O
that	O
these	O
drives	O
were	O
very	O
fast	O
.	O
</s>
<s>
The	O
floppy	B-Device
disks	I-Device
themselves	O
relied	O
on	O
an	O
MS-DOS	B-Application
disk	O
format	O
,	O
and	O
being	O
based	O
on	O
cartridge	O
allowed	O
the	O
Commodore	O
64	O
to	O
boot	O
from	O
them	O
automatically	O
at	O
start-up	O
.	O
</s>
<s>
Late	O
in	O
1984	O
,	O
Fiscal	O
Information	O
Inc.	O
,	O
of	O
Florida	O
,	O
demonstrated	O
the	O
Lt	B-Device
.	I-Device
Kernal	I-Device
hard	B-Device
drive	I-Device
subsystem	O
for	O
the	O
C64	O
.	O
</s>
<s>
The	O
Lt	B-Device
.	I-Device
Kernal	I-Device
mated	O
a	O
10	O
megabyte	O
Seagate	O
ST-412	B-Device
hard	B-Device
drive	I-Device
to	O
an	O
OMTI	O
SASI	O
intelligent	O
controller	O
,	O
creating	O
a	O
high	O
speed	O
bus	O
interface	O
to	O
the	O
C64	O
's	O
expansion	O
port	O
.	O
</s>
<s>
Connection	O
of	O
the	O
SASI	O
bus	O
to	O
the	O
C64	O
was	O
accomplished	O
with	O
a	O
custom	O
designed	O
host	B-Architecture
adapter	I-Architecture
.	O
</s>
<s>
The	O
Lt	B-Device
.	I-Device
Kernal	I-Device
shipped	O
with	O
a	O
disk	O
operation	O
system	O
(	O
DOS	B-Operating_System
)	O
that	O
,	O
among	O
other	O
things	O
,	O
allowed	O
execution	O
of	O
a	O
program	O
by	O
simply	O
typing	O
its	O
name	O
and	O
pressing	O
the	O
Return	O
key	O
.	O
</s>
<s>
The	O
DOS	B-Operating_System
also	O
included	O
a	O
keyed	O
random	O
access	O
feature	O
that	O
made	O
it	O
possible	O
for	O
a	O
skilled	O
programmer	O
to	O
implement	O
ISAM	B-Application
style	O
databases	O
.	O
</s>
<s>
By	O
1987	O
,	O
the	O
manufacturing	O
and	O
distribution	O
of	O
the	O
Lt	B-Device
.	I-Device
Kernal	I-Device
had	O
been	O
turned	O
over	O
to	O
Xetec	O
,	O
Inc.	O
,	O
who	O
also	O
introduced	O
C128	B-Device
compatibility	O
(	O
including	O
support	O
for	O
CP/M	B-Application
)	O
.	O
</s>
<s>
Standard	O
drive	O
size	O
had	O
been	O
increased	O
to	O
20	O
MB	O
,	O
with	O
40	O
MB	O
available	O
as	O
an	O
option	O
,	O
and	O
the	O
system	O
bus	O
was	O
now	O
the	O
industry-standard	O
small	B-Architecture
computer	I-Architecture
system	I-Architecture
interface	I-Architecture
,	O
better	O
known	O
as	O
SCSI	B-Architecture
(	O
the	O
direct	O
descendant	O
of	O
SASI	O
)	O
.	O
</s>
<s>
The	O
Lt	B-Device
.	I-Device
Kernal	I-Device
was	O
capable	O
of	O
a	O
data	O
transfer	O
rate	O
of	O
over	O
per	O
second	O
(	O
65	O
kB	O
per	O
second	O
in	O
C128	B-Device
fast	O
mode	O
)	O
.	O
</s>
<s>
An	O
optional	O
multiplexer	O
allowed	O
one	O
Lt	B-Device
.	I-Device
Kernal	I-Device
drive	O
to	O
be	O
shared	O
by	O
as	O
many	O
as	O
sixteen	O
C64s	O
or	O
C128s	O
(	O
in	O
any	O
combination	O
)	O
,	O
using	O
a	O
round-robin	B-Algorithm
scheduling	I-Algorithm
algorithm	I-Algorithm
that	O
took	O
advantage	O
of	O
the	O
SCSI	B-Architecture
bus	O
protocol	O
's	O
ability	O
to	O
handle	O
multiple	O
initiators	B-Device
and	O
targets	B-Device
.	O
</s>
<s>
Thus	O
the	O
Lt	B-Device
.	I-Device
Kernal	I-Device
could	O
be	O
conveniently	O
used	O
in	O
a	O
multi-computer	O
setup	O
,	O
something	O
that	O
was	O
not	O
possible	O
with	O
other	O
C64-compatible	O
hard	B-Device
drives	I-Device
.	O
</s>
<s>
Production	O
of	O
the	O
Lt	B-Device
.	I-Device
Kernal	I-Device
ceased	O
in	O
1991	O
.	O
</s>
<s>
In	O
2010	O
,	O
a	O
re-creation	O
of	O
the	O
Lt	B-Device
.	I-Device
Kernal	I-Device
was	O
produced	O
by	O
MyTec	O
Electronics	O
.	O
</s>
<s>
It	O
was	O
called	O
the	O
Rear	O
Admiral	O
HyperDrive	O
and	O
used	O
an	O
upgraded	O
DOS	B-Operating_System
called	O
RA-DOS	O
.	O
</s>
<s>
The	O
Rear	O
Admiral	O
parts	O
could	O
be	O
used	O
to	O
upgrade	O
the	O
older	O
Lt	B-Device
.	I-Device
Kernal	I-Device
,	O
e.g.	O
</s>
<s>
chips	O
from	O
the	O
Rear	O
Admiral	O
host	B-Architecture
adapter	I-Architecture
could	O
be	O
used	O
to	O
upgrade	O
the	O
chips	O
in	O
the	O
Lt	B-Device
.	I-Device
Kernal	I-Device
host	B-Architecture
adapter	I-Architecture
;	O
or	O
if	O
the	O
Lt	B-Device
.	I-Device
Kernal	I-Device
is	O
missing	O
its	O
host	B-Architecture
adapter	I-Architecture
,	O
the	O
Rear	O
Admiral	O
host	B-Architecture
adapter	I-Architecture
could	O
be	O
used	O
in	O
its	O
place	O
.	O
</s>
<s>
Much	O
like	O
the	O
Commodore	B-Device
1541	I-Device
floppy	B-Device
drive	I-Device
,	O
the	O
CMD	O
HD	O
could	O
connect	O
to	O
the	O
Commodore	O
64	O
's	O
serial	B-Protocol
bus	I-Protocol
,	O
and	O
could	O
operate	O
independently	O
of	O
the	O
computer	O
with	O
the	O
help	O
of	O
its	O
on-board	O
hardware	O
.	O
</s>
<s>
A	O
CMD	O
HD	O
series	O
drive	O
included	O
its	O
own	O
SCSI	B-Architecture
controller	O
to	O
operate	O
its	O
hard	B-Device
drive	I-Device
mechanism	O
,	O
in	O
addition	O
to	O
hosting	O
a	O
battery	O
powered	O
real-time	O
clock	O
module	O
for	O
the	O
time-stamping	O
of	O
files	O
.	O
</s>
<s>
The	O
stock	O
operating	O
speeds	O
of	O
the	O
CMD	O
HD-Series	O
units	O
were	O
not	O
very	O
much	O
faster	O
than	O
the	O
stock	O
speeds	O
of	O
a	O
1541	B-Device
floppy	B-Device
drive	I-Device
,	O
but	O
the	O
units	O
were	O
fully	O
JiffyDOS	O
compatible	O
.	O
</s>
<s>
Faster	O
parallel	O
transfers	O
were	O
possible	O
with	O
the	O
addition	O
of	O
another	O
CMD	O
product	O
,	O
the	O
CMD	B-General_Concept
RAMLink	I-General_Concept
and	O
a	O
special	O
parallel	O
transfer	O
cable	O
.	O
</s>
<s>
With	O
this	O
arrangement	O
,	O
the	O
performance	O
of	O
the	O
system	O
doubled	O
that	O
of	O
the	O
Lt	B-Device
.	I-Device
Kernal	I-Device
.	O
</s>
<s>
One	O
advantage	O
the	O
CMD	O
products	O
had	O
was	O
software	O
compatibility	O
,	O
especially	O
with	O
GEOS	B-Device
,	O
that	O
prior	O
solutions	O
lacked	O
.	O
</s>
<s>
However	O
,	O
external	O
SCSI	B-Architecture
devices	O
(	O
such	O
as	O
the	O
iOmega	B-Operating_System
zip	I-Operating_System
100	O
drive	O
)	O
could	O
be	O
connected	O
to	O
a	O
CMD	O
HD	O
series	O
drive	O
's	O
external	O
SCSI	B-Architecture
port	O
.	O
</s>
<s>
Using	O
the	O
same	O
utility	O
software	O
diskette	B-Device
shipped	O
with	O
all	O
CMD	O
HD	O
series	O
drives	O
,	O
the	O
external	O
storage	O
could	O
then	O
be	O
easily	O
added	O
to	O
CMD	O
HD	O
series	O
drive	O
's	O
existing	O
partition	O
table	O
.	O
</s>
<s>
The	O
ICT	O
DataChief	O
included	O
a	O
hard	B-Device
drive	I-Device
,	O
along	O
with	O
an	O
Indus	B-Device
GT	I-Device
floppy	B-Device
drive	I-Device
,	O
along	O
with	O
a	O
135-watt	O
power	O
supply	O
in	O
a	O
case	O
designed	O
to	O
house	O
an	O
IBM	B-Device
PC	I-Device
Compatible	O
computer	O
.	O
</s>
<s>
User	O
operation	O
of	O
these	O
hard	B-Device
drive	I-Device
subsystems	O
was	O
similar	O
to	O
that	O
of	O
Commodore	O
's	O
floppy	B-Device
drives	I-Device
,	O
with	O
the	O
inclusion	O
of	O
special	O
DOS	B-Operating_System
features	O
to	O
make	O
best	O
use	O
of	O
the	O
drive	O
's	O
capabilities	O
and	O
to	O
effectively	O
manage	O
the	O
vast	O
increase	O
in	O
storage	O
capacity	O
(	O
up	O
to	O
a	O
maximum	O
of	O
4GB	O
)	O
.	O
</s>
<s>
An	O
unavoidable	O
problem	O
was	O
that	O
total	O
1541	B-Device
compatibility	O
could	O
not	O
be	O
achieved	O
,	O
which	O
often	O
prevented	O
the	O
use	O
of	O
copy-protected	O
software	O
,	O
software	O
fastloaders	B-Device
,	O
or	O
any	O
software	O
whose	O
operation	O
depended	O
on	O
exact	O
1541	B-Device
emulation	O
.	O
</s>
<s>
The	O
enthusiast-built	O
"	O
IDE64	B-Device
interface	O
"	O
was	O
designed	O
late	O
in	O
the	O
1990s	O
,	O
attaching	O
itself	O
in	O
the	O
Commodore	O
64	O
's	O
expansion	O
port	O
,	O
and	O
allowing	O
users	O
to	O
attach	O
common	O
IDE	B-Protocol
hard	I-Protocol
drives	I-Protocol
,	O
CD-ROM	B-Device
and	O
DVD	O
drives	O
,	O
ZiP	B-Operating_System
and	O
LS-120	B-Device
floppy	B-Device
drives	I-Device
to	O
their	O
Commodore	O
64s	O
.	O
</s>
<s>
Later	O
revisions	O
of	O
the	O
interface	O
board	O
provided	O
an	O
extra	O
compact	B-Device
flash	I-Device
socket	O
.	O
</s>
<s>
The	O
IDE	B-Protocol
interface	O
's	O
performance	O
is	O
comparable	O
to	O
the	O
RAMLink	B-General_Concept
in	O
speed	O
,	O
but	O
lacks	O
the	O
intelligence	O
of	O
SCSI	B-Architecture
.	O
</s>
<s>
Its	O
main	O
advantage	O
lies	O
in	O
being	O
able	O
to	O
use	O
inexpensive	O
commodity	O
hard	B-Device
drives	I-Device
instead	O
of	O
the	O
more	O
costly	O
SCSI	B-Architecture
units	O
.	O
</s>
<s>
1541	B-Device
compatibility	O
is	O
not	O
as	O
good	O
as	O
commercially	O
developed	O
hard	B-Device
drive	I-Device
subsystems	O
,	O
but	O
continues	O
to	O
improve	O
with	O
time	O
.	O
</s>
<s>
Commodore-specific	O
printers	O
were	O
attached	O
to	O
the	O
C64	O
via	O
the	O
serial	O
port	O
and	O
were	O
capable	O
of	O
being	O
daisy	O
chained	O
to	O
the	O
system	O
with	O
other	O
serial	O
port	O
devices	O
such	O
as	O
floppy	B-Device
drives	I-Device
.	O
</s>
<s>
By	O
convention	O
,	O
printers	O
were	O
addressed	O
as	O
device	O
#4	O
-5	O
on	O
the	O
CBM-488	B-Protocol
serial	B-Protocol
bus	I-Protocol
.	O
</s>
<s>
A	O
series	O
of	O
dot-matrix	B-General_Concept
printers	O
were	O
sold	O
by	O
Commodore	O
,	O
including	O
the	O
MPS	O
801	O
(	O
OEM	O
Seikosha	O
GP	O
500	O
VC	O
)	O
and	O
the	O
MPS	O
803	O
,	O
although	O
many	O
other	O
third-party	O
printers	O
like	O
the	O
Okimate	B-Device
10	I-Device
and	O
Okidata	O
120	O
were	O
popular	O
too	O
-	O
some	O
having	O
more	O
advanced	O
printing	O
features	O
than	O
any	O
of	O
Commodore	O
's	O
models	O
.	O
</s>
<s>
Commodore	O
also	O
produced	O
the	O
DPS-1101	O
daisy	O
wheel	O
printer	O
,	O
which	O
produced	O
letter	O
quality	O
print	O
similar	O
to	O
a	O
typewriter	O
based	O
on	O
a	O
Juki	O
mechanism	O
,	O
and	O
which	O
typically	O
cost	O
more	O
than	O
the	O
computer	O
and	O
floppy	B-Device
disk	I-Device
drive	I-Device
together	O
.	O
</s>
<s>
The	O
MPS-1000	O
dot	B-General_Concept
matrix	I-General_Concept
printer	O
was	O
introduced	O
along	O
with	O
the	O
C-128	O
.	O
</s>
<s>
the	O
Atari	B-Device
1020	I-Device
)	O
.	O
</s>
<s>
Since	O
there	O
were	O
severe	O
shortcomings	O
of	O
early	O
Commodore	O
printers	O
,	O
CARDCO	O
released	O
the	O
Card	O
Print	O
A	O
(	O
C/	O
?	O
A	O
)	O
printer	O
interface	O
that	O
emulated	O
Commodore	O
printers	O
by	O
converting	O
the	O
Commodore-style	O
CBM-bus	B-Protocol
IEEE-488	O
serial	O
interface	O
to	O
a	O
Centronics	B-Device
printer	I-Device
port	I-Device
to	O
allow	O
numerous	O
3rd-party	O
printers	O
to	O
be	O
connected	O
to	O
a	O
Commodore	O
64	O
,	O
such	O
as	O
Epson	O
,	O
Okidata	O
,	O
C	O
.	O
Itoh	O
.	O
</s>
<s>
A	O
second	O
model	O
,	O
a	O
version	O
that	O
supported	O
printer	O
graphics	O
was	O
released	O
called	O
the	O
Card	O
Print	O
+G	O
(	O
C/	O
?	O
+G	O
)	O
,	O
supported	O
printing	O
Commodore	O
graphic	O
characters	O
using	O
ESC/P	B-Language
escape	O
codes	O
.	O
</s>
<s>
Later	O
,	O
CMD	O
created	O
the	O
GeoCable	O
which	O
allowed	O
PS2-type	O
ink-jet	O
and	O
laser	O
printers	O
to	O
work	O
under	O
GEOS	B-Device
with	O
a	O
special	O
device	B-Application
driver	I-Application
.	O
</s>
<s>
Printer	O
buffer	B-General_Concept
with	O
64	O
kB	O
RAM	B-Architecture
for	O
the	O
CBM-bus	B-Protocol
IEC	O
IEEE-488	O
derative	O
serial	B-Protocol
bus	I-Protocol
existed	O
too	O
,	O
like	O
the	O
"	O
Brachman	O
Associates	O
Serial	O
Box	O
Print	O
Buffer	B-General_Concept
"	O
.	O
</s>
<s>
The	O
Commodore	O
64	O
has	O
two	O
Atari	B-Protocol
joystick	I-Protocol
ports	I-Protocol
.	O
</s>
<s>
Commodore	O
produced	O
joystick	B-Device
controllers	O
for	O
the	O
Commodore	O
64	O
,	O
largely	O
compatible	O
with	O
Atari	O
joysticks	B-Device
,	O
as	O
well	O
as	O
paddles	B-Device
(	O
which	O
were	O
not	O
Atari	O
compatible	O
)	O
.	O
</s>
<s>
Commodore	O
's	O
paddles	B-Device
were	O
originally	O
intended	O
for	O
the	O
VIC-20	B-Device
,	O
and	O
few	O
C64	O
games	O
could	O
take	O
advantage	O
of	O
them	O
.	O
</s>
<s>
The	O
"	O
Atari	O
CX85	O
Numerical	B-Device
Keypad	I-Device
"	O
consists	O
of	O
a	O
numeric	B-Device
keypad	I-Device
featuring	O
the	O
17	O
keys	O
[escape],	O
[no],	O
[delete],	O
[yes],	O
0-9	O
,	O
[	O
.	O
</s>
<s>
It	O
connects	O
to	O
the	O
C64	O
joystick	B-Device
port	O
using	O
the	O
Atari	B-General_Concept
2600	I-General_Concept
style	O
interface	O
with	O
a	O
DB9F	O
plug	O
.	O
</s>
<s>
Commodore	O
had	O
three	O
models	O
of	O
computer	B-Device
mouse	I-Device
,	O
namely	O
the	O
NEOS	O
Mouse	O
(	O
Bundled	O
with	O
some	O
packs	O
of	O
C64	O
as	O
part	O
of	O
the	O
Mouse	O
Cheese	O
pack	O
)	O
,	O
the	O
1350	O
and	O
the	O
1351	B-Device
.	O
</s>
<s>
These	O
were	O
used	O
with	O
GEOS	B-Device
as	O
well	O
as	O
software	O
such	O
as	O
Jane	B-Application
,	O
OCP	O
Art	O
Studio	O
,	O
Arkanoid	O
and	O
Magic	B-Protocol
Desk	I-Protocol
.	O
</s>
<s>
It	O
also	O
supported	O
a	O
joystick	B-Device
emulation	O
mode	O
if	O
the	O
left	O
button	O
was	O
held	O
down	O
during	O
power-on	O
.	O
</s>
<s>
The	O
later	O
1350	O
was	O
only	O
capable	O
of	O
emulating	O
a	O
digital	O
joystick	B-Device
,	O
by	O
sending	O
rapid	O
8	O
directional	O
signals	O
as	O
it	O
was	O
moved	O
,	O
and	O
was	O
the	O
least	O
useful	O
of	O
the	O
3	O
mice	O
.	O
</s>
<s>
Its	O
successor	O
the	O
1351	B-Device
,	O
like	O
the	O
NEOS	O
Mouse	O
,	O
supported	O
the	O
more	O
traditional	O
analogue	O
mode	O
,	O
known	O
as	O
'	O
proportional	O
mode	O
 '	O
in	O
the	O
documentation	O
,	O
sending	O
signals	O
to	O
the	O
computer	O
that	O
indicate	O
amount	O
and	O
direction	O
of	O
movement	O
.	O
</s>
<s>
Like	O
the	O
NEOS	O
mouse	O
,	O
it	O
could	O
be	O
put	O
into	O
a	O
1350-esque	O
joystick	B-Device
emulation	O
mode	O
,	O
by	O
holding	O
down	O
the	O
right	O
button	O
at	O
power-on	O
.	O
</s>
<s>
CMD	O
's	O
SmartMouse	O
was	O
compatible	O
with	O
1351-aware	O
and	O
also	O
included	O
a	O
third	O
button	O
and	O
a	O
built-in	O
real-time	O
clock	O
module	O
as	O
well	O
.	O
</s>
<s>
Several	O
Companies	O
produced	O
Lightpens	B-Device
with	O
its	O
own	O
drawing	O
software	O
for	O
the	O
Computer	O
,	O
e.g.	O
</s>
<s>
the	O
Inkwell	O
light	B-Device
pen	I-Device
which	O
was	O
compatible	O
with	O
GEOS	B-Device
.	O
</s>
<s>
The	O
Koala	B-Application
Pad	I-Application
graphics	B-Device
tablet	I-Device
was	O
also	O
available	O
,	O
came	O
with	O
its	O
own	O
paint	O
software	O
,	O
and	O
was	O
compatible	O
with	O
GEOS	B-Device
as	O
well	O
.	O
</s>
<s>
Suncom	O
's	O
Animation	O
Station	O
was	O
another	O
graphics	B-Device
tablet	I-Device
for	O
the	O
C64	O
.	O
</s>
<s>
Test	O
technicians	O
at	O
CGAD	O
Productions	O
operations	O
developed	O
and	O
installed	O
the	O
CarPilot	O
Computerized	O
Automotive	O
Relative	O
Performance	O
Indicator	O
and	O
Location	O
of	O
Transit	O
,	O
one	O
of	O
the	O
first	O
car	B-Application
navigation	I-Application
systems	I-Application
to	O
be	O
tested	O
,	O
circa	O
1984	O
.	O
</s>
<s>
It	O
utilized	O
a	O
Commodore	O
64	O
,	O
converter	O
,	O
video	O
player/recorder	O
,	O
datasette	B-Device
,	O
and	O
a	O
TV	O
monitor	O
.	O
</s>
<s>
The	O
use	O
of	O
assembly	B-Language
language	I-Language
was	O
necessitated	O
to	O
keep	O
up	O
with	O
sensor	O
input	O
.	O
</s>
<s>
Interfaces	O
for	O
all	O
popular	O
home	O
computers	O
at	O
the	O
time	O
were	O
made	O
,	O
including	O
Apple	B-Device
II	I-Device
,	O
Commodore	O
64	O
and	O
Acorn	O
,	O
and	O
later	O
for	O
Schneider	O
,	O
Atari	B-Device
ST	I-Device
and	O
IBM	B-Device
PC	I-Device
.	O
</s>
<s>
Programming	O
languages	O
to	O
drive	O
the	O
models	O
included	O
GW-BASIC	B-Language
,	O
Turbo	B-Application
Pascal	I-Application
and	O
in	O
the	O
later	O
kits	O
(	O
1991	O
)	O
an	O
in-house	O
programming	O
tool	O
Lucky	B-General_Concept
Logic	I-General_Concept
.	O
</s>
<s>
The	O
"	O
Commocoffee	O
64	O
"	O
is	O
an	O
espresso	B-Device
maker	O
controlled	O
by	O
the	O
C64	O
in	O
1985	O
.	O
</s>
<s>
The	O
device	O
is	O
programmed	O
on	O
the	O
VIC-20	B-Device
with	O
and	O
I/O	O
at	O
37136	O
.	O
</s>
<s>
The	O
latter	O
could	O
also	O
be	O
accomplished	O
using	O
the	O
Datasette	B-Device
and	O
software	O
tricks	O
.	O
</s>
<s>
In	O
1987	O
there	O
was	O
a	O
cartridge	O
port	O
device	O
to	O
measure	O
EEG	B-Application
directly	O
for	O
use	O
in	O
exercise	O
programs	O
,	O
called	O
"	O
BodyLink	O
"	O
produced	O
by	O
the	O
company	O
Bodylog	O
in	O
New	O
York	O
City	O
,	O
USA	O
.	O
</s>
<s>
Frame	B-Device
grabbers	I-Device
like	O
the	O
"	O
PAL	O
Colour	O
Digitizer	O
"	O
that	O
connect	O
via	O
the	O
user	O
port	O
,	O
will	O
turn	O
an	O
analog	O
composite	O
video	O
frame	O
into	O
a	O
digital	O
picture	O
on	O
the	O
C64	O
.	O
</s>
<s>
It	O
includes	O
an	O
expansion	O
ROM	B-Device
that	O
adds	O
BASIC	O
4.0	O
commands	O
.	O
</s>
<s>
The	O
"	O
Z80	B-General_Concept
Video	O
Pack	O
80	O
"	O
enabled	O
black	O
and	O
white	O
80-column	O
screen	O
and	O
CP/M	B-Application
using	O
a	O
Zilog	B-General_Concept
Z80	I-General_Concept
.	O
</s>
<s>
As	O
Commodore	O
offered	O
a	O
number	O
of	O
inexpensive	O
modems	B-Application
for	O
the	O
C64	O
,	O
such	O
as	O
the	O
1650	O
,	O
1660	O
,	O
1670	O
,	O
the	O
machine	O
also	O
helped	O
popularize	O
the	O
use	O
of	O
modems	B-Application
for	O
telecommunications	O
.	O
</s>
<s>
The	O
1670	O
used	O
a	O
modified	O
set	O
of	O
Hayes	O
AT	B-Device
commands	I-Device
.	O
</s>
<s>
This	O
modem	B-Application
is	O
required	O
for	O
Medical	O
Manager	O
for	O
EDI	O
operations	O
.	O
</s>
<s>
It	O
provided	O
basic	O
Xmodem	B-Protocol
functionality	O
and	O
contained	O
a	O
700	O
line	O
scrollback	O
feature	O
.	O
</s>
<s>
In	O
the	O
United	O
States	O
,	O
Commodore	O
offered	O
the	O
Commodore	O
Information	B-Architecture
Network	I-Architecture
,	O
a	O
CompuServe	O
SIG	O
devoted	O
to	O
its	O
products	O
and	O
users	O
.	O
</s>
<s>
In	O
the	O
UK	O
,	O
Compunet	O
was	O
a	O
very	O
popular	O
online	O
service	O
for	O
C64	O
users	O
(	O
requiring	O
special	O
Compunet	O
modems	B-Application
)	O
from	O
1984	O
to	O
the	O
early	O
1990s	O
.	O
</s>
<s>
In	O
Australia	O
,	O
Telecom	O
(	O
now	O
Telstra	O
)	O
ran	O
an	O
online	O
service	O
called	O
Viatel	O
and	O
sold	O
modems	B-Application
for	O
the	O
C64	O
for	O
use	O
with	O
the	O
service	O
.	O
</s>
<s>
In	O
Germany	O
the	O
very	O
restrictive	O
rules	O
of	O
the	O
state-owned	O
telephone	O
system	O
prevented	O
widespread	O
use	O
of	O
inexpensive	O
,	O
non-telco	O
licensed	O
modems	B-Application
,	O
prompting	O
the	O
use	O
of	O
inferior	O
acoustic	B-Device
couplers	I-Device
instead	O
.	O
</s>
<s>
"	O
Microlog	O
AIR-1	O
Radio	O
Interface	O
Cartridge	O
"	O
that	O
use	O
the	O
C64	O
cartridge	O
port	O
with	O
builtin	O
ROM	B-Device
software	O
for	O
RTTY	O
and	O
morse	O
code	O
communications	O
.	O
</s>
<s>
"	O
Auerswald	O
ACC-64	O
"	O
longwave	B-Algorithm
time	O
signal	O
for	O
the	O
DCF77	O
transmitter	O
.	O
</s>
<s>
Like	O
the	O
VIC-20	B-Device
,	O
the	O
C64	O
lacked	O
a	O
real	O
UART	O
chip	O
such	O
as	O
the	O
6551	B-Architecture
and	O
used	O
software	O
emulation	O
.	O
</s>
<s>
Later	O
in	O
the	O
Commodore	O
64	O
's	O
life	O
,	O
CMD	O
developed	O
two	O
serial	B-Protocol
communications	I-Protocol
cartridges	O
for	O
Commodore	O
Computers	O
,	O
the	O
"	O
Swiftlink	O
"	O
-	O
and	O
the	O
"	O
Turbo	O
232	O
"	O
-	O
The	O
latter	O
was	O
capable	O
of	O
handling	O
a	O
56k	O
Hayes	O
modem	B-Application
reliably	O
at	O
full	O
speed	O
on	O
a	O
enabling	O
reasonable	O
dial-up	O
internet	O
access	O
speeds	O
.	O
</s>
<s>
The	O
Retro-Replay	O
expansion	O
cartridge	O
enabled	O
the	O
addition	O
of	O
the	O
Silver	O
Surfer	O
add-on	O
serial	O
board	O
,	O
which	O
also	O
enabled	O
56k	O
modem	B-Application
connections	O
,	O
and	O
the	O
RR-Net	O
add-on	O
serial	O
board	O
,	O
which	O
allows	O
for	O
broadband	O
internet	O
access	O
,	O
as	O
well	O
as	O
LAN	B-General_Concept
.	O
</s>
<s>
One	O
of	O
uses	O
were	O
hard	B-Device
disks	I-Device
like	O
the	O
Commodore	B-Device
D9060	I-Device
.	O
</s>
<s>
It	O
uses	O
the	O
6502	B-General_Concept
,	O
6532	B-Device
,	O
6522	B-Device
,	O
6850	O
and	O
2716	O
EPROM	B-General_Concept
chips	O
.	O
</s>
<s>
The	O
1902	O
had	O
a	O
true	O
RGBI	B-Device
80-column	O
mode	O
compatible	O
with	O
IBM	B-Device
PCs	I-Device
.	O
</s>
<s>
These	O
included	O
the	O
"	O
Sound	O
Expander	O
"	O
,	O
"	O
Sound	O
Sampler	O
"	O
,	O
"	O
Music	O
Maker	O
"	O
overlay	B-General_Concept
,	O
and	O
External	O
music	O
keyboard	O
.	O
</s>
<s>
The	O
Music	O
Maker	O
was	O
a	O
plastic	O
overlay	B-General_Concept
for	O
the	O
Commodore	O
64	O
"	O
breadbox	O
"	O
keyboard	O
,	O
which	O
included	O
plastic	O
piano	O
keys	O
corresponding	O
to	O
keys	O
on	O
the	O
keyboard	O
.	O
</s>
<s>
Possibly	O
the	O
most	O
complex	O
C64	O
peripheral	O
was	O
the	O
Mimic	O
Systems	O
Spartan	O
,	O
which	O
added	O
an	O
entire	O
new	O
computer	O
architecture	O
to	O
the	O
C64	O
,	O
with	O
its	O
own	O
6502	B-General_Concept
CPU	O
and	O
expansion	O
bus	O
,	O
for	O
software	O
and	O
hardware	O
compatibility	O
with	O
the	O
Apple	B-Device
II	I-Device
series	I-Device
.	O
</s>
<s>
Essentially	O
an	O
Apple	O
II+	O
compatible	O
computer	O
that	O
used	O
the	O
64	O
's	O
keyboard	O
,	O
video	O
output	O
,	O
joysticks	B-Device
,	O
and	O
cassette	O
recorder	O
,	O
the	O
Spartan	O
included	O
64kB	O
RAM	B-Architecture
,	O
a	O
motherboard	B-Device
with	O
a	O
6502	B-General_Concept
CPU	O
on	O
a	O
card	O
,	O
8	O
Apple-compatible	O
expansion	O
slots	O
,	O
an	O
Apple-compatible	O
disk	O
controller	O
card	O
,	O
and	O
a	O
DOS	B-Operating_System
board	O
to	O
add	O
to	O
your	O
1541	B-Device
disk	O
drive	O
.	O
</s>
<s>
The	O
DOS	B-Operating_System
board	O
was	O
optional	O
,	O
but	O
if	O
it	O
was	O
not	O
installed	O
an	O
Apple	B-Device
Disk	I-Device
II	I-Device
or	O
compatible	O
drive	O
would	O
be	O
required	O
to	O
load	O
software	O
.	O
</s>
<s>
The	O
long	O
delay	O
between	O
announcement	O
and	O
availability	O
,	O
along	O
with	O
heavy	O
promotion	O
including	O
full-page	O
ads	O
running	O
monthly	O
in	O
the	O
Commodore	O
press	O
,	O
made	O
the	O
Spartan	O
an	O
infamous	O
example	O
of	O
vaporware	B-Application
.	O
</s>
<s>
Gamesware	O
produced	O
a	O
gaming	B-Application
peripheral	I-Application
for	O
the	O
Commodore	O
64	O
in	O
1988	O
,	O
where	O
a	O
target	O
board	O
was	O
attached	O
to	O
the	O
computer	O
using	O
the	O
RS-232	O
port	O
to	O
enable	O
use	O
of	O
its	O
Gamma	B-Application
Strike	I-Application
suite	O
of	O
games	O
.	O
</s>
<s>
This	O
saved	O
Commodore	O
64	O
users	O
from	O
needing	O
to	O
modify	O
their	O
computer	B-Device
motherboards	I-Device
to	O
enable	O
it	O
with	O
dual	O
SID	O
chips	O
.	O
</s>
<s>
Creative	O
Micro	O
Designs	O
(	O
CMD	O
)	O
was	O
the	O
longest-running	O
third-party	O
hardware	O
vendor	O
for	O
the	O
Commodore	O
64	O
and	O
Commodore	B-Device
128	I-Device
,	O
hailed	O
by	O
some	O
enthusiasts	O
as	O
being	O
better	O
at	O
supporting	O
the	O
Commodore	O
64	O
than	O
Commodore	O
themselves	O
.	O
</s>
<s>
Their	O
first	O
commercial	O
product	O
for	O
the	O
C64	O
was	O
a	O
KERNAL	B-Operating_System
based	O
fast	B-Device
loader	I-Device
and	O
utility	O
chip	O
called	O
JiffyDOS	O
.	O
</s>
<s>
It	O
was	O
not	O
the	O
first	O
KERNAL-based	O
enhancement	O
for	O
the	O
C64	O
(	O
SpeedDOS	O
and	O
DolphinDOS	B-Device
also	O
existed	O
)	O
,	O
but	O
was	O
perhaps	O
the	O
best	O
implemented	O
.	O
</s>
<s>
The	O
benefits	O
of	O
a	O
KERNAL	B-Operating_System
upgrade	O
meant	O
that	O
the	O
cartridge	O
port	O
was	O
free	O
for	O
use	O
(	O
which	O
would	O
have	O
normally	O
been	O
taken	O
up	O
by	O
an	O
Epyx	B-Application
FastLoad	I-Application
cartridge	O
or	O
an	O
Action	B-Device
Replay	I-Device
)	O
,	O
however	O
the	O
downside	O
meant	O
that	O
one	O
had	O
to	O
manually	O
remove	O
computer	O
chips	O
from	O
the	O
C64	O
's	O
motherboard	B-Device
and	O
associated	O
floppy	B-Device
drives	I-Device
to	O
install	O
it	O
.	O
</s>
<s>
Aside	O
from	O
the	O
usual	O
1541	B-Device
fast	O
load	O
routines	O
,	O
JiffyDOS	O
contained	O
an	O
easy	O
to	O
use	O
DOS	B-Operating_System
and	O
a	O
few	O
other	O
useful	O
utilities	O
.	O
</s>
<s>
Over	O
the	O
years	O
,	O
a	O
number	O
of	O
RAM	B-Architecture
expansion	O
cartridges	O
were	O
developed	O
for	O
the	O
Commodore	O
64	O
and	O
128	O
.	O
</s>
<s>
Commodore	O
officially	O
produced	O
several	O
models	O
of	O
RAM	B-Architecture
expansion	O
cartridges	O
,	O
referred	O
to	O
collectively	O
as	O
the	O
17xx-series	O
Commodore	B-General_Concept
REUs	I-General_Concept
.	O
</s>
<s>
Typically	O
,	O
most	O
Commodore	O
64	O
users	O
did	O
not	O
require	O
a	O
RAM	B-Architecture
expansion	O
.	O
</s>
<s>
The	O
cost	O
of	O
the	O
units	O
(	O
and	O
the	O
requirement	O
to	O
add	O
a	O
heavy-duty	O
power	O
supply	O
)	O
also	O
was	O
a	O
factor	O
in	O
the	O
limited	O
usage	O
of	O
RAM	B-Architecture
expansion	O
cartridges	O
.	O
</s>
<s>
The	O
volatility	O
of	O
DRAM	O
was	O
also	O
a	O
factor	O
in	O
the	O
limited	O
usage	O
,	O
as	O
the	O
RAM	B-Architecture
expansion	O
cartridges	O
were	O
normally	O
used	O
for	O
fast	O
RAM	B-Application
disk	I-Application
storage	O
,	O
data	O
stored	O
on	O
them	O
would	O
be	O
lost	O
at	O
any	O
power	O
failure	O
.	O
</s>
<s>
Aside	O
from	O
power-supply	O
problems	O
,	O
the	O
other	O
main	O
downfall	O
of	O
the	O
RAM	B-Architecture
expansions	O
were	O
their	O
limited	O
usability	O
due	O
to	O
their	O
technical	O
implementation	O
.	O
</s>
<s>
The	O
RAM	B-Architecture
in	O
the	O
expansion	O
cartridges	O
was	O
only	O
accessible	O
via	O
a	O
handful	O
of	O
hardware	O
registers	O
,	O
rather	O
than	O
being	O
CPU-addressable	O
memory	O
.	O
</s>
<s>
This	O
meant	O
that	O
users	O
could	O
not	O
access	O
this	O
RAM	B-Architecture
without	O
complicated	O
programming	O
techniques	O
.	O
</s>
<s>
Furthermore	O
,	O
simply	O
adding	O
the	O
RAM	B-Architecture
expansion	O
did	O
not	O
provide	O
any	O
kind	O
of	O
on-board	O
RAM	B-Application
disk	I-Application
functionality	O
(	O
though	O
a	O
utility	O
disk	O
was	O
supplied	O
with	O
some	O
REUs	O
,	O
which	O
provided	O
a	O
loadable	O
RAM	B-Application
disk	I-Application
driver	O
)	O
.	O
</s>
<s>
One	O
popular	O
exception	O
to	O
the	O
disuse	O
of	O
the	O
REUs	O
was	O
GEOS	B-Device
.	O
</s>
<s>
As	O
GEOS	B-Device
made	O
heavy	O
use	O
of	O
a	O
primitive	O
,	O
software-controlled	O
form	O
of	O
swap	O
space	O
,	O
it	O
tended	O
to	O
be	O
slow	O
when	O
used	O
exclusively	O
with	O
floppy	B-Device
disks	I-Device
or	O
hard	B-Device
drives	I-Device
.	O
</s>
<s>
With	O
the	O
addition	O
of	O
an	O
REU	O
,	O
along	O
with	O
a	O
small	O
software	B-Application
driver	I-Application
,	O
GEOS	B-Device
would	O
use	O
the	O
expanded	O
memory	O
in	O
place	O
of	O
its	O
usual	O
swap	O
space	O
,	O
increasing	O
GEOS	B-Device
 '	O
operating	O
speed	O
.	O
</s>
<s>
Due	O
to	O
the	O
lack	O
of	O
available	O
17xx-series	O
Commodore	B-General_Concept
REUs	I-General_Concept
,	O
and	O
then	O
their	O
later	O
discontinuation	O
,	O
Berkeley	O
Softworks	O
,	O
the	O
publishers	O
of	O
GEOS	B-Device
,	O
developed	O
their	O
own	O
512	O
kB	O
RAM	B-Architecture
expansion	O
cartridge	O
-	O
the	O
GeoRAM	O
.	O
</s>
<s>
This	O
device	O
was	O
purposely	O
designed	O
for	O
use	O
with	O
GEOS	B-Device
,	O
although	O
some	O
REU-aware	O
programs	O
were	O
later	O
adapted	O
to	O
be	O
able	O
to	O
use	O
it	O
.	O
</s>
<s>
Some	O
time	O
later	O
,	O
the	O
GeoRAM	O
was	O
cloned	O
by	O
another	O
company	O
to	O
form	O
the	O
BBGRAM	O
device	O
(	O
which	O
also	O
sported	O
a	O
battery	O
backup	B-Protocol
unit	O
)	O
.	O
</s>
<s>
This	O
method	O
provided	O
substantially	O
slower	O
transfer	O
speeds	O
than	O
the	O
single-cycle-per-byte	O
transfer	O
speeds	O
of	O
the	O
Commodore	B-General_Concept
REUs	I-General_Concept
.	O
</s>
<s>
Eventually	O
the	O
Super	B-General_Concept
1750	I-General_Concept
Clone	I-General_Concept
,	O
a	O
third-party	O
clone	O
of	O
Commodore	O
's	O
RAM	B-Architecture
expansions	O
was	O
developed	O
,	O
designed	O
in	O
such	O
a	O
way	O
as	O
to	O
eliminate	O
the	O
need	O
for	O
a	O
heavy-duty	O
power	O
supply	O
.	O
</s>
<s>
PPI	O
devised	O
their	O
own	O
externally	O
powered	O
1	O
or	O
2	O
MB	O
RAM	B-Architecture
expansion	O
,	O
marketed	O
as	O
the	O
PPI/CMD	O
RAMDrive	B-Application
,	O
which	O
was	O
explicitly	O
designed	O
to	O
be	O
used	O
as	O
a	O
RAM	B-Application
disk	I-Application
.	O
</s>
<s>
Its	O
primary	O
feature	O
was	O
that	O
the	O
external	O
power	O
supply	O
kept	O
the	O
formatting	O
and	O
contents	O
of	O
the	O
RAM	B-Architecture
safe	O
and	O
valid	O
while	O
the	O
computer	O
was	O
turned	O
off	O
,	O
in	O
addition	O
to	O
powering	O
the	O
device	O
in	O
any	O
case	O
.	O
</s>
<s>
A	O
driver	O
was	O
provided	O
on	O
the	O
included	O
utilities	O
disk	O
to	O
allow	O
GEOS	B-Device
to	O
use	O
the	O
RAMdrive	B-Application
as	O
a	O
regular	O
'	O
disk	O
 '	O
drive	O
.	O
</s>
<s>
CMD	O
later	O
followed	O
up	O
with	O
the	O
RAMLink	B-General_Concept
.	O
</s>
<s>
This	O
device	O
operated	O
similar	O
to	O
the	O
RAMDrive	B-Application
,	O
but	O
could	O
address	O
up	O
to	O
16	O
MB	O
of	O
RAM	B-Architecture
in	O
the	O
form	O
of	O
a	O
17xx-series	O
REU	O
,	O
GeoRAM	O
,	O
and/or	O
an	O
internal	O
memory	O
card	O
,	O
which	O
also	O
provided	O
a	O
battery-backed	O
realtime	O
clock	O
for	O
file	O
time/date	O
stamping	O
of	O
files	O
saved	O
to	O
it	O
.	O
</s>
<s>
It	O
also	O
features	O
a	O
battery	O
backup	B-Protocol
,	O
thus	O
preserving	O
the	O
RAM	B-Architecture
's	O
contents	O
.	O
</s>
<s>
Drivers	O
were	O
provided	O
with	O
the	O
RAMLink	B-General_Concept
to	O
allow	O
GEOS	B-Device
to	O
use	O
its	O
memory	O
as	O
either	O
a	O
replacement	O
for	O
swap	O
space	O
,	O
or	O
as	O
a	O
regular	O
'	O
disk	O
 '	O
drive	O
.	O
</s>
<s>
CMD	O
's	O
Super	O
CPU	O
Accelerator	O
came	O
after	O
this	O
and	O
could	O
house	O
up	O
to	O
of	O
direct	O
,	O
CPU-addressable	O
RAM	B-Architecture
.	O
</s>
<s>
Unfortunately	O
,	O
there	O
was	O
no	O
on-board	O
or	O
disk-based	O
RAM	B-Application
disk	I-Application
functionality	O
offered	O
,	O
nor	O
could	O
any	O
existing	O
software	O
make	O
use	O
of	O
the	O
directly	O
addressable	O
nature	O
of	O
the	O
RAM	B-Architecture
.	O
</s>
<s>
The	O
exception	O
is	O
that	O
drivers	O
were	O
included	O
with	O
the	O
unit	O
to	O
explicitly	O
allow	O
GEOS	B-Device
to	O
use	O
that	O
RAM	B-Architecture
as	O
a	O
replacement	O
for	O
swap	O
space	O
,	O
or	O
as	O
a	O
regular	O
'	O
disk	O
 '	O
drive	O
,	O
as	O
well	O
as	O
to	O
make	O
use	O
of	O
the	O
acceleration	O
offered	O
by	O
the	O
unit	O
.	O
</s>
<s>
Programmers	O
for	O
EPROMs	B-General_Concept
like	O
2716	O
-	O
27256	O
using	O
common	O
programming	O
voltages	O
(	O
Vpp	O
)	O
of	O
12.5	O
,	O
21	O
,	O
and	O
25	O
V	O
were	O
available	O
by	O
connecting	O
a	O
device	O
to	O
the	O
user	O
port	O
of	O
the	O
C64	O
.	O
</s>
<s>
The	O
device	O
often	O
included	O
a	O
zero	B-General_Concept
insertion	I-General_Concept
force	I-General_Concept
(	O
ZIF	O
)	O
socket	O
and	O
a	O
LED	O
indicating	O
when	O
the	O
EPROM	B-General_Concept
chip	O
was	O
being	O
programmed	O
.	O
</s>
<s>
As	O
the	O
C64	O
had	O
no	O
built-in	O
soft	B-Device
reset	I-Device
switch	O
,	O
reset	O
cartridges	O
were	O
popular	O
for	O
entering	O
game	O
"	O
POKEs	B-Language
"	O
(	O
codes	O
which	O
changed	O
parts	O
of	O
a	O
game	O
's	O
code	O
in	O
order	O
to	O
cheat	O
)	O
from	O
popular	O
Commodore	O
computer	O
magazines	O
.	O
</s>
<s>
In	O
addition	O
,	O
these	O
cartridges	O
had	O
tools	O
for	O
editing	O
game	O
sprites	O
,	O
machine	B-General_Concept
language	I-General_Concept
monitors	I-General_Concept
,	O
floppy	B-Device
fast	B-Device
loaders	I-Device
,	O
and	O
other	O
development	O
tools	O
.	O
</s>
<s>
Despite	O
containing	O
many	O
powerful	O
tools	O
for	O
the	O
programmer	O
,	O
they	O
were	O
also	O
accused	O
of	O
aiding	O
unauthorized	O
distributors	O
to	O
defeat	O
software	B-Application
copy	I-Application
protections	I-Application
.	O
</s>
<s>
Perhaps	O
the	O
best-known	O
freezer	O
cartridges	O
were	O
the	O
Datel	O
"	O
Action	B-Device
Replay	I-Device
"	O
,	O
Evesham	O
Micros	O
Freeze	B-General_Concept
Frame	O
MK	O
III	O
B	O
,	O
Trilogic	O
"	O
Expert	O
"	O
,	O
"	O
The	B-Device
Final	I-Device
Cartridge	I-Device
III	I-Device
"	O
,	O
Super	O
Snapshot	O
and	O
ISEPIC	B-Device
cartridges	O
.	O
</s>
<s>
The	O
Lt	B-Device
.	I-Device
Kernal	I-Device
hard	B-Device
drive	I-Device
subsystem	O
included	O
a	O
push	O
button	O
on	O
the	O
host	B-Architecture
adapter	I-Architecture
called	O
ICQUB	O
(	O
pronounced	O
"	O
ice	O
cube	O
"	O
)	O
,	O
which	O
could	O
be	O
used	O
to	O
halt	O
a	O
running	O
program	O
and	O
capture	O
a	O
RAM	B-Application
image	I-Application
to	O
disk	O
.	O
</s>
<s>
This	O
would	O
work	O
with	O
most	O
copy-protected	O
software	O
that	O
did	O
not	O
do	O
disk	B-General_Concept
overlays	I-General_Concept
and/or	O
bypass	O
the	O
KERNAL	B-Operating_System
ROM	B-Device
jump	O
table	O
.	O
</s>
<s>
The	O
RAM	B-Application
image	I-Application
was	O
runnable	O
only	O
on	O
the	O
Lt	B-Device
.	I-Device
Kernal	I-Device
system	O
on	O
which	O
it	O
was	O
captured	O
,	O
thus	O
preventing	O
the	O
process	O
from	O
being	O
used	O
to	O
distribute	O
unlicensed	O
software	O
.	O
</s>
<s>
Various	O
assemblers	B-Language
,	O
notators	O
,	O
sequencers	O
,	O
MIDI	O
editing	O
and	O
mixer	O
automation	O
software	O
were	O
created	O
which	O
allowed	O
users	O
and	O
programmers	O
to	O
create	O
or	O
record	O
musical	O
pieces	O
of	O
impressive	O
technical	O
complexity	O
.	O
</s>
<s>
Some	O
software	O
of	O
note	O
has	O
included	O
the	O
Kawasaki	O
Synthesizer	O
range	O
,	O
Music	O
System	O
notation	O
and	O
MIDI	O
suite	O
,	O
the	O
MIDI-compatible	O
Instant	O
Music	O
'	O
idiot-proof	O
'	O
sequential	O
composer	O
,	O
and	O
the	O
Steinberg	O
Pro-16	O
MIDI	O
sequencer	O
,	O
the	O
precursor	O
to	O
Cubase	B-Application
.	O
</s>
<s>
It	O
came	O
with	O
the	O
"	O
DOS	B-Operating_System
Card	O
"	O
addition	O
,	O
an	O
Apple	B-Device
II	I-Device
disk	O
controller	O
that	O
was	O
installed	O
inside	O
the	O
Commodore	B-Device
1541	I-Device
disk	O
drive	O
,	O
between	O
the	O
floppy	B-Device
logic	B-Device
board	I-Device
and	O
the	O
drive	O
mechanism	O
.	O
</s>
<s>
In	O
normal	O
mode	O
the	O
circuit	O
simply	O
passed	O
signals	O
through	O
but	O
at	O
the	O
flick	O
of	O
a	O
switch	O
it	O
could	O
take	O
over	O
the	O
mechanism	O
and	O
turn	O
the	O
drive	O
into	O
an	O
Apple	B-Device
II	I-Device
drive	O
.	O
</s>
<s>
The	O
potential	O
for	O
grave	O
damage	O
to	O
both	O
Apple	B-Device
II	I-Device
and	O
1541	B-Device
floppies	B-Device
was	O
enormous	O
and	O
often	O
happened	O
.	O
</s>
<s>
Applesoft	O
BASIC	O
was	O
included	O
and	O
very	O
compatible	O
,	O
since	O
it	O
was	O
created	O
by	O
disassembling	O
the	O
binary	O
from	O
the	O
Applesoft	O
ROM	B-Device
and	O
reordering	O
the	O
assembly	O
level	O
instructions	O
such	O
that	O
the	O
binary	O
image	O
would	O
be	O
different	O
.	O
</s>
<s>
The	O
Commodore	O
C64	O
CP/M	B-Application
Cartridge	O
uses	O
the	O
C1541	B-Device
floppy	B-Device
drive	I-Device
which	O
was	O
incapable	O
of	O
reading	O
any	O
existing	O
CP/M	B-Application
disk	O
format	O
.	O
</s>
<s>
Like	O
the	O
Apple	B-Device
II	I-Device
family	I-Device
,	O
third-party	O
acceleration	O
units	O
providing	O
a	O
faster	O
CPU	O
appeared	O
late	O
in	O
the	O
C64	O
's	O
life	O
.	O
</s>
<s>
So	O
while	O
accelerators	O
based	O
upon	O
the	O
Western	O
Design	O
Center	O
(	O
WDC	O
)	O
65C02usually	O
running	O
at	O
4MHz	O
,	O
and	O
the	O
WDC	B-General_Concept
65C816	I-General_Concept
16-bit	O
microprocessor	O
running	O
at	O
4	O
,	O
8	O
or	O
20MHz	O
,	O
were	O
produced	O
,	O
they	O
appeared	O
too	O
late	O
and	O
were	O
too	O
expensive	O
to	O
gain	O
widespread	O
use	O
.	O
</s>
<s>
It	O
used	O
the	O
WDC	B-General_Concept
65C816	I-General_Concept
microprocessor	O
running	O
at	O
4.09MHz	O
.	O
</s>
<s>
Code	O
ran	O
from	O
faster	O
static	B-Architecture
RAM	I-Architecture
on	O
the	O
accelerator	O
expansion	O
port	O
cartridge	O
.	O
</s>
<s>
The	O
Turbo	O
Master	O
CPU	O
had	O
one	O
beneficial	O
modification	O
,	O
the	O
bit	O
to	O
toggle	O
the	O
high-speed	O
mode	O
on	O
was	O
"	O
0	O
"	O
in	O
memory	B-General_Concept
location	I-General_Concept
$00	O
as	O
opposed	O
to	O
the	O
"	O
1	O
"	O
the	O
Turbo	O
Process	O
.	O
</s>
<s>
The	O
most	O
well-known	O
accelerator	O
for	O
the	O
C64	O
is	O
probably	O
Creative	O
Micro	O
Designs	O
 '	O
SuperCPU	O
,	O
which	O
was	O
equipped	O
with	O
the	O
WDC	O
W65C816S	B-General_Concept
(	O
the	O
static	B-General_Concept
core	I-General_Concept
version	O
of	O
the	O
65C816	B-General_Concept
)	O
clocked	O
at	O
20MHz	O
,	O
and	O
with	O
up	O
to	O
16MB	O
of	O
RAM	B-Architecture
if	O
combined	O
with	O
CMD	O
's	O
SuperRamCard	O
.	O
</s>
<s>
Understandably	O
,	O
due	O
to	O
a	O
very	O
limited	O
"	O
market	O
"	O
and	O
number	O
of	O
developers	O
,	O
there	O
has	O
not	O
been	O
much	O
software	O
tailored	O
for	O
the	O
SuperCPU	O
to	O
date	O
—	O
however	O
GEOS	B-Device
was	O
supported	O
.	O
</s>
<s>
Among	O
the	O
few	O
offerings	O
available	O
are	O
the	O
Wheels	O
;	O
a	O
Wheels-based	O
web	O
browser	O
called	O
"	O
The	O
Wave	O
"	O
,	O
a	O
Unix/QNX	O
-like	O
graphical	O
OS	O
called	O
Wings	O
,	O
some	O
demos	O
,	O
various	O
classic	O
games	O
modified	O
for	O
use	O
with	O
the	O
SuperCPU	O
,	O
and	O
a	O
shooter	O
game	O
in	O
the	O
old	O
Katakis-style	O
called	O
Metal	O
Dust	O
.	O
</s>
<s>
The	O
MMC64	O
cartridge	O
allows	O
the	O
C64	O
to	O
access	O
MMC	O
-	O
and	O
SD	O
flash	B-Device
memory	I-Device
cards	O
.	O
</s>
<s>
It	O
features	O
an	O
Amiga	B-Device
clock	B-Device
port	I-Device
for	O
connecting	O
a	O
RR-Net	O
Ethernet-Interface	O
,	O
an	O
MP3	B-Application
player	O
add-on	O
called	O
'	O
mp3@c64	O
 '	O
has	O
even	O
been	O
produced	O
for	O
it	O
.	O
</s>
<s>
It	O
contains	O
many	O
improvements	O
,	O
such	O
as	O
C128	B-Device
compatibility	O
,	O
a	O
built-in	O
.d64	O
mounter	O
(	O
not	O
speedloader-compatible	O
though	O
,	O
because	O
the	O
1541	B-Device
CPU	O
is	O
not	O
emulated	O
)	O
,	O
ROM	B-Device
for	O
a	O
total	O
of	O
eight	O
cartridges	O
,	O
512	O
kB	O
RAM	B-Architecture
,	O
a	O
built-in	O
flash-tool	O
for	O
cartridge	O
images	O
and	O
wider	O
support	O
for	O
various	O
types	O
of	O
cartridges	O
(	O
not	O
merely	O
Action-replay-based	O
)	O
.	O
</s>
<s>
In	O
April	O
2008	O
,	O
the	O
first	O
batch	O
of	O
1541	B-Device
Ultimate	I-Device
shipped	O
,	O
a	O
project	O
by	O
the	O
hobbyist	O
VHDL-developer	O
Gideon	O
Zweijtzer	O
.	O
</s>
<s>
This	O
is	O
a	O
cartridge	O
that	O
carries	O
an	O
Action	B-Device
Replay	I-Device
and	O
Final	B-Device
Cartridge	I-Device
(	O
whatever	O
the	O
user	O
prefers	O
)	O
and	O
a	O
very	O
compatible	O
FPGA-emulated	O
1541	B-Device
drive	O
that	O
is	O
fed	O
from	O
a	O
built-in	O
SD-card	B-Device
slot	O
(	O
.d64	O
,	O
prg	O
etc	O
.	O
)	O
.	O
</s>
<s>
The	O
difference	O
to	O
other	O
SD-based	O
and	O
.d64	O
mounting	O
cartridges	O
like	O
the	O
MMC64	O
,	O
Super	O
Snapshot	O
2007	O
or	O
MMC	O
Replay	O
is	O
,	O
that	O
the	O
6502	B-General_Concept
that	O
powers	O
the	O
1541	B-Device
Floppy	B-Device
and	O
the	O
1541	B-Device
's	O
mechanical	O
behavior	O
(	O
even	O
sound	O
)	O
is	O
fully	O
emulated	O
,	O
making	O
it	O
theoretically	O
compatible	O
with	O
almost	O
anything	O
.	O
</s>
<s>
The	O
1541	B-Device
Ultimate	I-Device
also	O
works	O
in	O
standalone	O
mode	O
without	O
a	O
c-64	O
,	O
functioning	O
just	O
like	O
a	O
normal	O
Commodore	B-Device
1541	I-Device
would	O
.	O
</s>
<s>
Disk-selection	O
of	O
.d64s	O
is	O
then	O
done	O
via	O
buttons	O
on	O
the	O
cartridge	O
,	O
power	O
is	O
supplied	O
via	O
USB	B-Protocol
.	O
</s>
<s>
There	O
is	O
a	O
"	O
Plus-Version	O
"	O
available	O
with	O
an	O
extra	O
32	O
Megabytes	O
of	O
RAM	B-Architecture
(	O
as	O
REU	O
and	O
for	O
future	O
use	O
)	O
,	O
the	O
basic	O
version	O
has	O
just	O
enough	O
RAM	B-Architecture
for	O
the	O
advertised	O
functions	O
to	O
work	O
.	O
</s>
<s>
In	O
October	O
2008	O
,	O
the	O
second	O
and	O
third	O
batch	O
of	O
1541	B-Device
Ultimates	I-Device
were	O
produced	O
to	O
match	O
the	O
public	O
demand	O
for	O
the	O
device	O
.	O
</s>
<s>
The	O
regular	O
version	O
without	O
the	O
32MB	O
RAM	B-Architecture
was	O
dropped	O
since	O
there	O
was	O
no	O
demand	O
for	O
it	O
.	O
</s>
<s>
In	O
2010	O
a	O
completely	O
new	O
PCB	O
and	O
software	O
has	O
been	O
developed	O
by	O
Gideon	O
Zweijtzer	O
to	O
facilitate	O
the	O
new	O
1541-Ultimate-II	O
cartridge	O
.	O
</s>
<s>
The	O
IDE64	B-Device
interface	I-Device
cartridge	I-Device
provides	O
access	O
to	O
parallel	B-Protocol
ATA	I-Protocol
drives	O
like	O
hard	B-Device
disks	I-Device
,	O
CD/DVD	O
drives	O
,	O
LS-120	B-Device
,	O
Zip	B-Operating_System
drives	I-Operating_System
,	O
and	O
CompactFlash	B-Device
cards	I-Device
.	O
</s>
<s>
It	O
also	O
supports	O
network	B-Architecture
drives	O
(	O
PCLink	O
)	O
to	O
directly	O
access	O
a	O
host	O
system	O
over	O
various	O
connection	O
methods	O
including	O
X1541	O
,	O
RS-232	O
,	O
Ethernet	O
and	O
USB	B-Protocol
.	O
</s>
<s>
The	O
operating	O
system	O
called	O
IDEDOS	B-Operating_System
provides	O
CBM/CMD	O
compatible	O
interface	O
to	O
programs	O
on	O
all	O
devices	O
.	O
</s>
<s>
The	O
main	O
filesystem	O
is	O
called	O
CFS	B-Device
,	O
but	O
there	O
's	O
read-only	O
support	O
for	O
ISO	B-Application
9660	I-Application
and	O
FAT12/16/32	B-Application
.	O
</s>
<s>
Additional	O
features	O
include	O
BASIC	B-Language
extension	I-Language
,	O
DOS	B-Operating_System
Wedge	I-Operating_System
,	O
file	B-Application
manager	I-Application
,	O
machine	B-General_Concept
code	I-General_Concept
monitor	I-General_Concept
,	O
fast	B-Device
loader	I-Device
,	O
BIOS	B-Operating_System
setup	O
screen	O
.	O
</s>
<s>
Today	O
's	O
computer	B-Device
mice	I-Device
can	O
be	O
attached	O
via	O
the	O
Micromys	O
interface	O
that	O
can	O
process	O
even	O
optical	O
mice	O
and	O
similar	O
.	O
</s>
<s>
A	O
board	O
for	O
converting	O
Commodore	O
64	O
video	O
signals	O
to	O
standard	O
VGA	B-Protocol
monitor	I-Protocol
output	O
is	O
also	O
currently	O
under	O
development	O
.	O
</s>
<s>
Also	O
,	O
a	O
board	O
to	O
convert	O
the	O
Commodore	B-Device
128	I-Device
's	O
80	O
column	O
RGBI	B-Device
CGA-compatible	B-Device
video	O
signal	O
to	O
VGA	B-Protocol
format	O
was	O
developed	O
in	O
late	O
2011	O
.	O
</s>
<s>
The	O
board	O
,	O
named	O
the	O
C128	B-Device
Video	O
DAC	O
,	O
had	O
a	O
limited	O
production	O
run	O
and	O
was	O
used	O
in	O
conjunction	O
with	O
the	O
more	O
widespread	O
GBS-8220	O
board	O
.	O
</s>
<s>
It	O
has	O
a	O
Retro-Replay	O
compatible	O
Freezer	O
and	O
MMC/SD	O
-Slot	O
,	O
REU	O
and	O
a	O
PS/2	B-Protocol
connector	I-Protocol
for	O
a	O
PC	O
Keyboard	O
.	O
</s>
<s>
Support	O
for	O
a	O
network	B-Architecture
adapter	O
and	O
battery-backed	O
real	O
time	O
clock	O
exists	O
.	O
</s>
<s>
The	O
cartridge	O
does	O
not	O
even	O
have	O
to	O
be	O
plugged	O
into	O
a	O
Commodore	O
64	O
and	O
can	O
be	O
used	O
as	O
a	O
standalone	O
device	O
using	O
USB	B-Protocol
power	O
.	O
</s>
<s>
Since	O
the	O
cartridge	O
essentially	O
also	O
includes	O
a	O
Commodore	O
One	O
it	O
is	O
possible	O
to	O
include	O
a	O
VGA	B-Protocol
Port	I-Protocol
that	O
outputs	O
the	O
picture	O
to	O
a	O
standard	O
PC	O
monitor	O
.	O
</s>
<s>
The	O
Commodore	O
One	O
core	O
also	O
allows	O
the	O
cartridge	O
to	O
be	O
used	O
as	O
a	O
CPU	O
accelerator	O
,	O
and	O
a	O
core	O
to	O
run	O
a	O
Amiga	B-Device
environment	O
in	O
standalone	O
mode	O
also	O
exists	O
.	O
</s>
<s>
Retro	O
Innovations	O
is	O
shipping	O
the	O
uIEC	O
device	O
,	O
which	O
utilizes	O
the	O
core	O
design	O
of	O
the	O
SD2IEC	O
project	O
to	O
provide	O
a	O
mass	O
media	O
solution	O
for	O
Commodore	O
8-bit	O
systems	O
that	O
utilize	O
the	O
Commodore	O
IEC	O
Serial	B-Protocol
Bus	I-Protocol
.	O
</s>
<s>
Manosoft	O
sells	O
the	O
C64SD	O
Infinity	O
,	O
another	O
SD	B-Device
card	I-Device
media	O
solution	O
which	O
uses	O
the	O
sd2iec	O
firmware	O
.	O
</s>
<s>
thefuturewas8bit	O
SD2IEC	O
Versions	O
are	O
available	O
packaged	O
to	O
resemble	O
a	O
miniature	O
1541	B-Device
disk	O
drive	O
.	O
</s>
