User`s manual
Section
7
Purchasing a Parallel Cable
CMD Technical Support can provide you with infonnation on where
to
purchase a parallel cable (we have not printed such infonnation in this
manual in case sources change).
If
you are thinking
of
purchasing your cable
elsewhere, make sure the connections listed
later
in
this
section are identical
with the cable you wish
to
purchase.
When inserting the cable into the user port, make sure the computer is
turned off and the user port plug-in card is
inserted
right side up. Otherwise
the user
port
can
be
damaged.
Making Your
Own
Parallel Cable
Those
of
you with experience in soldering can easily make your own
parallel cable. Be sure to follow the connection directions below. A false
connection will destroy chips in the computer
or
printer.
You will
need
the following parts: a C-64 user port plug, a centronics plug,
a not too long cable (up to 6 ft.) with
at
least
11
wires (preferably shielded
cable, though we have seen ribbon cable used), a soldering iron and solder. .
The connection must look like this:
USER PORT CENTRONICS
A GND 16
GND
B
Flail:
11
Busy
C
PBO
2
Data in 0
D
PBl
3
Data in 1
E PB2 4
Data in 2
F PB3
5
Data in 3
H
PB4
6
Datain4
J
PBS
7
Data in 5
K PB6
8
Data in 6
L PB7
9
Data in 7
M PA2 1 Strobe
Make sure you mark the top side
of
the user port plug!
The
user port
assignments can
be
found in the back
of
you computer manual. You can
also connect pin 14 (auto-linefeed) and
31
(printer reset) from the centronics
plug via switches to ground (pin 16). Then you are able to switch the auto-
linefeed
and
start a
reset
These connections have
been
tested out on many 9
and 24 pin printers without complications.
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