C2N CASSETTE UNIT OPERATING INSTRUCTIONS
SUITABLE FOR USE WITH VIC, PET & CBM SERIES COMPUTERS
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The information in this manual has been reviewed and is believed to be
entirely reliable. No responsibility, however, is assumed for
inaccuracies. The material in this manual is for information purposes
only, and is subject to change without notice.
(C) Commodore Business Machines Ltd. 1981
"All rights reserved"
OPERATING INSTRUCTIONS FOR YOUR C2N CASSETTE UNIT
A COMMODORE C2N cassette unit is a device for storing and/or recalling
computer programs on ordinary cassette tapes. It can be used for
saving programs you have written and want to recall for later use. It
can also be used to read pre-recorded programs that you have purchased.
CASSETTE OPERATING INSTRUCTIONS FOR YOUR COMPUTER
Important information about your cassette unit
The COMMODORE C2N cassette unit is supplied with a cord attached. This
cord connects the cassette unit to the computer. Power is supplied
from the computer to the unit through this cord. The computer and the
cassette communicate through the cord as well.
TURN OFF THE COMPUTER BEFORE CONNECTING THE CASSETTE UNIT TO IT.
For VIC computer users
The cassette unit plugs on to a connector at the back of the computer.
See the figure below. The plug will only fit on the connector one way.
DO NOT FORCE IT.
It is also important to keep the cassette unit at least 2 feet away
from the TV as radio emissions from the TV can interfere with the
correct operation of the cassette unit.
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| C2N | | VIC 20 / C64 |
| + | | _________________ __ __ _____ __________ |
|_____|_____| |__|_______________|_(__)_(__)_|_+_|_|________|__|
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|_________________________________________|
FOR CBM/PET COMPUTER USERS
For CBM/PET computers, 4000 and 8000, the cassette unit plugs on to a
connector at the back of the computer.
[ Photograph omitted ]
PRELIMINARY CHECKOUT
Before using your cassette drive unit to recall or store programs, you
should complete the preliminary checks -- which are described below:
STEP 1 -- Turn off the computer and plug in the cassette unit.
STEP 2 -- Ensure that the cassette deck motor is off by checking that
all of the function keys are up. If any are not, press the STOP/EJECT
button.
STEP 3 -- Turn the computer on.
Fig. 1
| |
| ______________________________ |
| | _________ | | a - Supply Spindle
| | a __ | | __ b | | b - Take-Up Spindle
| | (__) |_______| (__) | | c - Erase Head
| | | | d - R/W Head Gap Area
| | __________________ | | e - Read/Write Head
| | / f \ | | f - Capstan
| | / _ | d_ O o__ \ | | g - Pinch Roller
| |__/___[_]_|=_[_]__(__)___\__| |
| | c e g | | h - (Record) REC
| |____________________________| | i - (Rewind) REW
| / __________________________ \ | j - (Fast Fwd) F.FWD
| / | h | i | j | k | l | \ | k - PLAY
|/ |____|____|____|____|____| \| l - STOP EJECT
|____________________________________|
STEP 4 -- Press the PLAY button on the cassette unit. Look to see
that, as the button is engagaed, the READ/WRITE heads move towards the
spindles and the capstan comes into contact with the pinch roller (see
Fig. 1). The take-up spindle should be moving smoothly in an anti-
clockwise direction.
STEP 5 -- Now press the STOP button. The heads should move back and
the spindle stop.
STEP 6 -- Press the REWIND button. The tape heads should remain in
the inactive position and the supply spindle should move rapidly
clockwise.
STEP 7 -- Press STOP again and then F.FWD. The tape heads should still
remain in the inactive position and the take-up spindle should move
rapidly anti-clockwise.
STEP 8 -- Press STOP once more and then GENTLY attempt to press REC.
You should feel strong mechanical resistance.
STEP 9 -- If all has worked properly proceed to the operations test on
the next page. If you have encountered any difficulties with the
preliminary checkout, please turn to the last page in this manual.
OPERATIONS TEST
To test the operation of your new cassette unit, let's write a short
program, SAVE it on to the cassette, and LOAD it back into the
computer.
Obtain a blank cassette (no special cassette is required) and place it
in the cassette unit. Always press REW to ensure that you are
starting at the beginning of the tape.
NOTE: A tape with playing time of 12 to 30 minutes is of ample length.
It is not advisable to use anything longer than this, as it strains
the motor.
STEP 1 -- On the keyboard type: 10 PRINT "THIS IS A TEST"
STEP 2 -- Press <RETURN>
STEP 3 -- Type: SAVE "TEST"
STEP 4 -- Press <RETURN>
The display will show:
for VIC PRESS RECORD & PLAY ON TAPE
for PET/CBM PRESS PLAY & RECORD ON TAPE No. 1
Do just that by pressing the REC, then while holding this button down,
pressing PLAY until both keys lock.
The display will show: OK
for VIC SAVING TEST
for PET/CBM WRITING TEST
and then after a few moments,
the display will show: READY
Your program has now been SAVED. Let's verify this.
STEP 5 -- Erase the memory by typing: NEW
then press <RETURN>
The display will show: READY
STEP 6 -- Type: LIST
then press <RETURN>
The display will show: READY
indicating that the memory is blank.
STEP 7 -- Rewind the cassette by pressing REW, then STOP when the tape
is at the beginning.
STEP 8 -- Type: LOAD "TEST"
the display will show:
for vic PRESS PLAY ON TAPE
for PET/CBM PRESS PLAY ON TAPE No. 1
After obeying the command,
the display will show: OK
SEARCHING FOR TEST
and after a short while: FOUND TEST
LOADING
READY
Note: If the computer displays: LOAD ERROR try the LOAD command a few
more times, but if the message repeats, turn to the last page.
STEP 9 -- Type: LIST
and press <RETURN>. Now the display will show that the memory has
received the program "TEST" by displaying
10 PRINT "THIS IS A TEST"
READY
If all of the preceding steps have been successfully completed, your
cassette has been properly checked and is ready to go to work. The
commands to use the cassette are described later in this manual.
NOTE: If any of the above steps does not work, turn to the last page
of this manual.
CARE OF TAPES
Be careful to rewind all tapes to the beginning after use as this
protects the recording from abrasion and contamination. Do not store
or place any tapes near strong magnetic fields such as may occur near
loudspeakers, or large motors.
CASSETTE MAINTENANCE
The cassette uses magnetic heads to record and retrieve the
information on the cassette tapes. These heads tend to accumulate
residue and dirt from the tape as the tape moves across them. After a
period of time the accumulation lifts the tape slightly away from the
heads drastically degrading the signal from the head.
Therefore, the following procedure should be used after every 10 to 20
hours of tape playing time to ensure that your cassette continues to
read and write reliably.
CLEANING AND DEMAGNETIZING YOUR CASSETTE HEADS
You'll need the following tools and materials:
1 -- Tape head cleaner. Alcohol may be used in emergency, but is not
recommended for long term use.
NOTE: Do not use trichloroethane or any other plastic or rubber
solvent.
2 -- Cotton swabs.
3 -- Tape head demagnetizer. Unit must have protective plastic or
rubber covering on the piece that comes into contact with the tape
heads so as not to scratch delicate head gap.
FOLLOW THIS PROCEDURE
STEP 1 -- Turn the computer off.
STEP 2 -- Press STOP/EJECT to open cover, then press PLAY to expose
heads.
STEP 3 -- Put tape head cleaner on one side of a cotton swab. Gently
wipe the surfaces of RECORD/PLAY and erase head (see Fig. 1). Scrub
gently. (If there is any build-up of tape oxide particles on or around
the head gap of the RECORD/PLAY head, it is sufficient reason for
unreliable performance.)
Also clean pinch roller and other tape bearing surfaces if tape head
cleaner is suitable for this purpose (check label).
STEP 4 -- Plug in demagnetizer, and activate it while it is at least
one foot away from cassette heads.
STEP 5 -- Slowly move demagnetizer up to RECORD/PLAY head and around
on head surface. Rate of motion should be approximately one inch per
second during this time.
STEP 6 -- Slowly move demagnetizer to erase head and then to all other
ferrous metal surfaces which come into proximity with the tape.
STEP 7 -- Now slowly move demagnetizer away from heads. Do not
deactivate field until demagnetizer is at least two feet away from
heads.
The tape head cleaning and demagnetizing procedure is now complete.
Inspect RECORD/PLAY surface for wear. If the tape has worn a groove
on head surface more than a couple of tape thicknesses deep, program
reading performance may be poor. If so, then replacement of tape head
is indicated. (Normally few thousand hours of tape running time have
been completed before replacement is required.)
CASSETTE OPERATION
Commands
Here are the commands that will activate your cassette drive unit.
Simply type the desired command and press <RETURN>. In the list of
commands below, NAME stands for the name that you, the user, assigns
to your program. You should select a name that will distinguish that
program from other programs (or data files) on the same tape. The
name should have a meaning to you. PROG1, PROG2. etc., are not good
choices because they are not distinctive. A program name can be no
more than 16 characters long.
SAVE "NAME" will SAVE a program by storing it on the cassette unit.
Example: SAVE"TEST"
will SAVE the program TEST on to the cassette unit.
NOTE: Simply typing SAVE will store the program without a name on the
cassette.
LOAD "NAME" will LOAD the program NAME from tape. All other programs
on the some tape will be ignored.
Example: LOAD"TEST"
will LOAD the program TEST from the cassette.
If LOAD is typed, then the first program found on the cassette will be
LOADed.
VERIFY "NAME" will VERIFY that the program which has been SAVED has
been stored correctly.
Example: VERIFY"TEST"
will search for and VERIFY the program named TEST on the cassette unit.
If the computer responds OK
with READY.
then the program has been
stored correctly. If, however,
the computer responds with VERIFY ERROR
READY
then the program on the tape has not been stored properly. Re-SAVE
the program and VERIFY again. If this still falls, then the cassette
is not working properly, the tape is of poor quality or the tape heads
need cleaning.
NOTE: VERIFY can be used to skip through a tape in order to SAVE a new
program at the end of other programs. The technique to use is
described here:
When you are ready to store the new program that is in your computer,
give the command VERIFY"NAME" using the name of the last program on
the tape. The computer will search for and VERIFY this last program
on the tape bypassing all other programs. Because the last program is
not the same as the new program currently in memory, the display will
read; VERIFY ERROR but the tape will have advanced to the end of all
the programs on the tape. You can then SAVE your new program, typing
SAVE"NAME", where NAME is the unique name of the new program that is
in your computer. The new program is now on the cassette immediately
after the other programs.
FILE HANDLING
Experienced programmers may write more sophisticated programs that use
large amounts of data. This data may be stored on a file on the
cassette. The commands to handle data files are explained below.
Files of data can be written to and read from the cassette unit.
These CANNOT be LOADed like a program, but can be read from by a
program. To communicate with the cassette unit, we use the OPEN
command:
OPEN A,B,C,"NAME"
This will OPEN a logical file where NAME identifies the file and:
A -- Is a reference integer from 1 to 255 chosen by the user. If a
program uses more than one file, each file must be a unique reference
integer.
B -- must be 1 for the cassette.
C -- specifies whether the program will WRITE to or READ from this
file, coded as follows:
If C=0 read from tape
C=1 write to tape with an End-Of-File marker to be written when the
file CLOSED.
C=2 write to tape with and End-Of-Tape marker to be written when the
file is CLOSED.
Example: OPEN5,1,1,"TEST"
will OPEN a file named "TEST" and having a reference integer of 5. The
program will WRITE to this file on the cassette.
If a value of 2 is chosen for C and "TEST" is chosen for the name,
this will WRITE an End-Of-Tape marker at the end of the file. If the
computer is then told to read a file which is after the file "TEST",
then when the computer has passed TEST it will respond with: FILE NOT
FOUND ERROR and stop. This is because the file "TEST" tells the
computer that the tape has ended -- regardless of whether it has or
not -- so the computer thinks that there are no more programs on the
tape.
C and NAME may be left out if the user wishes. If NAME is not used,
the file will be OPENed without a name. When a READ instruction is
given by the computer, it will read the first file that it finds. If C
is left out, then the file will be OPENed for READ.
INPUT # A,D will input data from the cassette and use it in the
program.
A -- is the logical file number used in a previous OPEN statement
which specifies READ from cassette.
D -- is the BASIC variable to which the data from the tape will be
transmitted. If words are to be read, then D should be D$ else the
error message FILE DATA ERROR will be displayed.
Example: INPUT # 5, A$
I will input
string data (words) from logical file 5, data will be read from the
cassette and assigned to the variable A$.
GET # is an alternative to INPUT # . GET # will get one character
(letter) at a time. GET # can read commas, colons, etc., whereas
INPUT # cannot.
PRINT # A,D will write data to the cassette where
A -- is the logical file number used in the previous OPEN statement
which specified WRITE to the cassette.
D -- is the BASIC variable from which the data is to be written. If
the data is words, then D$ must be used.
Example: PRINT# 5,A$
will output the string A$ to logical file 5 on the tape provided the
file has been OPENed for write. If the file was not properly OPENed,
NOT OUTPUT FILE will be displayed.
CLOSE A will close the file designated A, where A refers to the file
number.
WARNING: If this command is not used after all the data has been
written to the cassette, some data may not be written to the cassette.
Here are some sample program segments which use the above commands:
Example program 1 -- writing data
10 OPEN 1,1,1,"TEST FILE"
20 FOR I=1 TO 10
30 PRINT # 1, I
40 NEXT
50 CLOSE 1
Line 10 OPENs file 1 for WRITE as TEST FILE. Line 20 Do everything
between "FOR" & "NEXT" 10 times. Line 30 PRINTs the variable I on to
the tape. Line 40 Goes back to line 20 for 10 times. Line 50 CLOSEs
the file.
Example program 2 -- reading data using INPUT
10 OPEN 1,1,0,"TEST FILE"
20 INPUT# 1,D$
30 PRINT D$
40 IF ST=0 GOTO 20
50 CLOSE 1
Line 10 OPENs the file for READ as TEST FILE. Line 20 Reads a string
from the tape into D$. Line 30 Prints the variable D$ on the screen.
Line 40 Checks the status of the cassette. If the tape is OK then
GOTO line 20. Line 50 CLOSEs the file as the status is not OK -- the
end of file.
Example program 3 -- reading data using GET
10 OPEN 1,1,0,"TEST FILE"
20 GET # 1,D$
30 PRINT D$;
40 IF ST=0 GOTO 20
50 CLOSE 1
Line 10 OPENs the file for READ as TEST FILE. Line 20 GETs a character
into D$. Line 30 Prints the character in variable D$ on the screen.
Line 40 Checks the status of the cassette. If the tape is OK then
GOTO line 20. Line 50 CLOSEs the file as the status is not OK.
CASSETTE DECK PROBLEMS
If you are experiencing problems with your cassette deck either
mechanically or electronically, return it to the dealer from whom it
was purchased. If the cassette deck is faulty and in warranty he will
replace it for you.
COMMODORE SERVICE POINTS
Commodore Business Machines, Inc.
Valley Forge Corporate Center
950 Rittenhouse Road
Norristown, PA 19403
Commodore Business Machines Limited
3370 Pharmacy Avenue
Agincourt, Ontario, Canada M1W2K4
Commodore Business Machines Limited
Ajax Avenue
Slough Trading Estate
Slough, Berks., SL1 4BD, England
Commodore Buromaschinen GMbH
Frankfurter Strasse 171-175
6078 Neu Isenburg
W. Germany
Commodore Japan Limited
Taisei-Denshi Building
8-14 Ikue 1-Chome
Asahi-Ku, Osaka 535, Japan
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| / |__/ c o m m o d o r e
| \___|__\ C O M P U T E R
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End of the Project 64 etext of the C2N Cassette Unit Operating
Instructions
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