Commodore 1531 Datassette User manual

INFORMATIONTO USER
"WARNING:THIS EQUIPMENT HAS BEEN CERTIFIEDTO COMPLY WITH
THELIMITS FOR A CLASS B COMPUTING DEVICE,PURSUANT TO SUB-
PARTJ OF PART15 OF FCC RULES.ONLY PERIPHERALS(COMPUTER
INPUT/OUTPUT DEVICES,TERMINALS,PRINTERS,ETC.) CERTIFIEDTO
COMPLY WITHTHE CLASS B LIMITS MAY BE ATTACHEDTO THIS
COMPUTER. OPERATIONWITHNON-CERTIFIEDPERIPHERALSIS LIKELY
TO RESULTIN INTERFERENCETO RADIOANDTV RECEPTION."
"THIS EQUIPMENT GENERATESANDUSES RADIOFREQUENCYENERGY
AND IF NOT INSTALLEDPROPERLY,THAT IS,INSTRICTACCORDANCE
WITHTHEMANUFACTURER'SINSTRUCTIONS, MAY CAUSE INTER-
FERENCETO RADIOANDTELEVISIONRECEPTION. IT HAS BEEN TYPE
TESTED ANDFOUND TO COMPLY WITH THE LIMITS FOR A CLASS B
COMPUTING DEVICEIN ACCORDANCE WITH THE SPECIFICATIONSIN
SUBPARTJ OF PART15OF FCCRULES, WHICHAREDESIGNEDTO
PROVIDEREASONABLEPROTECTION AGAINSTSUCH INTERFERENCE
IN A RESIDENTIALINSTALLATION.HOWEVER,THEREISNOGUAR-
ANTEETHATINTERFERENCEWILLNOT OCCUR INA PARTICULAR
INSTALLATION.IF THIS EQUIPMENT DOES CAUSE INTERFERENCETO
RADIOOR TELEVISIONRECEPTION, WHICH CAN BE DETERMINEDBY
TURNINGTHE EQUIPMENT OFFANDON, THE USER ISENCOURAGED TO
TRYTO CORRECTTHE INTERFERENCEBY ONE OR MORE OF THE
FOLLOWINGMEASURES:
•REORIENTTHE RECEIVINGANTENNA
•RELOCATETHE COMPUTER WITH RESPECT TO
THERECEIVER
•MOVE THE COMPUTER AWAYFROM THE RECEIVER
•PLUG THE COMPUTER INTO A DIFFERENTOUTLET
SO THAT COMPUTER AND RECEIVERAREON DIFFERENT
BRANCHCIRCUITS
"IF NECESSARY,THE USER SHOULD CONSULT THE DEALEROR AN
EXPERIENCEDRADIO/TELEVISIONTECHNICIANFOR ADDITIONAL
SUGGESTIONS. THE USER MAY FIND THE FOLLOWING BOOKLET PRE-
PAREDBY THE FEDERALCOMMUNICATIONS COMMISSION HELPFUL:
'HOW TO IDENTIFYAND RESOLVERADIO-TVINTERFERENCE
PROBLEMS.'THIS BOOKLETIS AVAILABLEFROM THE U.S.GOVERN-
MENT PRINTINGOFFICE,WASHINGTON, D.C. 20402, STOCK NO.004-
000-00345-4."
PARTNO:320970
©Commodore ElectronicsLtd. 1984
Allrightsreserved

OPERATINGINSTRUCTIONSFORYOUR
1531DATASSETTE
TM
ACOMMODRE 1531DATASSETTE* unitis a deviceforstoringand recalling
computerprogramson ordinarycassettetapes. Itcan be used forsaving
programsyouhave writtenand wanttorecallforlateruse. Itcan alsobe used
toread pre-recordedprogramsthat youhave purchased.
*DATASSETTE isa trademark of Commodore Electronics Ltd.

DATASSETTE™ OPERATINGINSTRUCTIONSFOR
YOUR COMPUTER
Importantinformationabout your DATASSETTE™
The COMMODORE 1531DATASSETTETM is suppliedwitha cordattached.
ThiscordconnectsDATASSETTE™ tothe TED seriescomputers(Commodore
16,116,232,264,V364). Power is suppliedfromthe computertotheunit through
thiscord.The computerand theDATASSETTE™ communicatethroughthecord
as well.
TURN OFF THE COMPUTER BEFORE CONNECTING THE DATASSETTE™ TO
IT.
ForCOMMODOREcomputerusers
The COMMODORE 1531DATASSETTE™ was designed foruse on theTED
seriescomputers.
The DATASSETTE™ plugs intoa connectorat theback of thecomputer.The
plug willonlyfiton theconnectorone way.DO NOT FORCE IT.
Itisalso important to keep the DATASSETTE™ at least 2 feetaway from
the TV because radio emissions from the TV can interferewiththe correct
operation of the DATASSETTE™.
2

PRELIMINARY CHECKOUT
Before using your DATASSETTE™ torecall or store programs, you should
complete the preliminary checks — which are described below:
STEP 1 Turn off the computer and plug inthe DATASSETTE™ .
STEP 2 Ensure that the DATASSETTE™ motor is off by checking that all of
the function keys are up.If anyare not, press the STOP button.
STEP 3 Turn the computer on.
Fig.1
•TAKE-UP
SPINDLE
CAPSTAN
PINCH
ROLLER
COUNTER
READ/WRITE
HEAD

STEP 4 Press the PLAYbutton onthe DATASSETTE™ . Lookto see that, as
the button isengaged,the READ/WRITE headsmovetowards the
spindles andthe capstan comes intocontact with the pinch roller
(see Fig.1).The take-up spindleshouldbemoving smoothly ina
counter-clockwise direction.
STEP 5 Nowpress the STOPbutton. The headsshould move back andthe
spindle stop.
STEP 6 Press the REWIND button. The tape headsshould remain in the
inactive position andthe supplyspindleshouldmove rapidly
clockwise.
STEP 7 Press STOPagain and then F.FWD. The tape headsshould still
remain inthe inactive position andthe take-up spindle shouldmove
rapidly counter-clockwise.
STEP 8 Press STOPonce more andthen GENTLY attempt to press
RECORD. You should feel strong mechanical resistance.
STEP 9 Ifall hasworked properly, proceed to the operations test on the
next page.Ifyou haveencountered any difficulties with the
preliminary checkout, please turn to the lastpageinthis manual.

CLEANINGAND DEMAGNETIZINGYOUR
DATASSETTE™ HEADS
You'llneed the following tools and materials:
1Tape headcleaner. Alcohol maybeusedinemergency, butisnot
recommended forlongterm use.
NOTE: Donotuse trichloroethane or any other plastic or rubber solvent.
2Cotton swabs.
3Tape headdemagnetizer. Unit musthave protective plastic or rubber
covering on the piece that comes intocontact with the tape headsso
as notto scratchdelicate headgap.

Followthesestepsto clean and demagnetize your DATASSETTE™
STEP1 Turn the computer off.
STEP 2 Press EJECT to opencover, then press PLAY to expose heads.
STEP 3 Puttape headcleaner onone side ofa cotton swab. Gently wipe
the surfaces of RECORD/PLAY anderase heads(see Fig.1).
Scrub gently. Any build-upof tape oxide particles onor around the
headgap ofthe RECORD/PLAY headmaycause unreliable
performance.
Also clean pinch roller andother tape bearing surfaces iftape head
cleaner issuitable for this purpose (check label).
STEP 4 Plugindemagnetizer, andactivate itwhile it isat least one foot
away from DATASSETTE™ heads.
STEP 5 Slowly movedemagnetizer upto RECORD/PLAY headandaround
onheadsurface. Rate of motion should beapproximately oneinch
persecond during this time.
STEP 6 Slowly movedemagnetizer to the erase headandthen toallother
ferrous metal surfaces which come intoproximity with the tape.
STEP 7 Now slowly move demagnetizer away from heads.Do not
deactivate field until demagnetizer isat least two feet away from
heads.
The tape headcleaning anddemagnetizing procedure isnow complete.
Inspect RECORD/PLAY surface for wear. Ifthe tape has worn a groove on
headsurface more than a couple of tape thicknesses deep,program reading
performance maybepoor. Ifso,then replacement of tape headisindicated.
Normally, a few thousand hours oftape running time have been completed
before replacement isrequired.

VERIFY"NAME"
will VERIFY that the program which hasbeenSAVEd hasbeenstored
correctly.
Example:VERIFY'TEST"
will search for andVERIFY the program namedTEST onthe cassette.
Ifthe computer respondsOK
with READY
then the program hasbeen
stored correctly. If,however,
the computer respondswith VERIFY ERROR
READY
then the program onthe tapehasnotbeenstored properly. Re-SAVEthe
program andVERIFY again.Ifthis still fails, then the DATASSETTE™isnot
working properly, the tape isofpoorquality, or the tape headsneedcleaning.
NOTE:VERIFY can beusedto skip through a tape inorder to SAVE a new
program atthe endofother programs. The technique to use is
described here:
When you are ready to store the new program that isinyour
computer, givethe command VERIFY"NAME" usingthe name of the
lastprogram onthe tape.Thecomputer will search for andVERIFY
this lastprogram onthe tape,bypassingall other programs. Because
the lastprogram isnotthe same asthe newprogram currently in
memory, the displaywill read;VERIFY ERROR butthe tape will have
advancedto the endofallthe programs onthe tape.You can then
SAVE your newprogram, typingSAVE"NAME", where NAME isthe
uniquenameof the newprogram that isinyour computer. The new
program isnowonthe cassette immediately after the other programs.

USINGTHE COUNTER
Your DATASSETTE™ has a 3-digit counter that you can use to findSAVEd
programs quickly. When you use the counter properly, you can advance or
rewind the tape to the location ofthe program you want to LOAD. This saves
time because the computer doesn't have to search the whole tape.
The counter runs whenever the tape isPLAYing, RECORDing, REWINDing,
or Fast Forwarding (F.FWD).
Here'show to use the counter to find a SAVEd program quickly:
1.Make sure your tape isrewound to the beginning.
2.Reset the counter to 000 by pressing the black button beside the
3-digit display.
3. Note the counter number when you areready to SAVE a program. This
number tells you where that program willbelocated on the tape.
4. Advance (F.FWD) or REWIND the tape to the counter number at which
you SAVEd the program you now want to LOAD.
5. Follow the regular LOAD procedure.
NOTE: The counter can'tworkaccurately unless you followsteps 1 and 2.
Don't reset the counterto 000unless you'reat the beginning of the
tape.

FILEHANDLING
Experienced programmers may writemore sophisticated programs that use
large amounts of data. This data maybestored ona file onthe cassette. The
commands to handle data filesare explained below.
Files of data can bewritten to andread from the DATASSETTE™ . These
CANNOT beLOADED like a program, butthey can beread by a program. To
communicate with the DATASSETTE™ , use the OPEN command.
OPEN A,B,C,"NAME"
This will OPEN a logical filewhere NAME identifies the fileand:
AChoose a reference number from 1 to 255. If your program uses more
than one file, each file must haveits own file number.
BMust be1 for the DATASSETTE™. This isyour device code.
CSpecifies whether the program will WRITE to or READ from this file,
codedas follows:
ifC = 0 read from tape
C=1 writeto tape with an End-Of-File marker to bewritten when the fileis
CLOSED.
C= 2 write to tape with an End-Of-Tapemarker to bewritten when the fileis
CLOSED.
Example: OPEN5,1,1,"TEST"
will OPEN a file named "TEST" with a filenumberof 5. The program will
WRITE to this fileonthe cassette.
Ifa value of2 ischosen forC and "TEST" ischosen forthe name,this will
WRITE onEnd-Of-Tapemarker at the endof the file. Ifthe computer isthen
told to read a filewhich isafter the file"TEST", then when the computer has
passed TEST itwill respondwith: FILENOTFOUND ERROR andstop.This is
because the file "TEST" tells the computer that the tape has ended—
regardless of whether it hasor not— so the computer thinks that there are no
14more programs onthe tape.

CandNAME may beleft out if the user wishes. IfNAME isnotused,the file
will beOPENed without a name.When a READ instruction isgiven bythe
computer, itwill readthe firstfilethat itfinds. If C isleft out, then the file will
beOPENed forREAD.
INPUT#A,D
will inputdata from the cassette anduse itinthe program.
Aisthe logical filenumberused ina previous OPEN statement which
specifies READ from cassette.
Disthe BASICvariable to which the data from the tape will be
transmitted. Ifwords are to beread, then D should beD$.The error
message FILE DATA ERROR will bedisplayed ifyou don't use D$.
Example; INPUT#5,A$
will inputstring data (words) from logical file5.Data will beread from
the cassette andassigned to the variable A$.
GET# isan alternative to INPUT # . GET# will get one character
(letter) ata time. GET # can read commas, colons, etc., whereas
INPUT # cannot.
PRINT #A,D
will write data to the cassette where
Aisthe logical file number usedinthe previous OPEN statement which
specified WRITE to the cassette.
Disthe BASICvariable from which the data isto bewritten. Ifthe data
iswords, then D$must beused.
Example: PRINT #5,A$
will outputthe string A$ to logical file 5 onthe tapeprovided the file
hasbeenOPENed for write.Ifthe filewas notproperly OPENed, NOT
OUTPUT FILE will bedisplayed.
CLOSEA
will close the file designated A, where A refersto the file number.
WARNING: Ifthis command isnotusedafter allthe data has.beenwritten to
the cassette, some data maynotbewritten to the cassette. 1 5

Here are some sample program segments which use the above commands:
Example program 1 — writing data
10OPEN1,1,1,"TEST FILE"
20 FORX=1T010
30PRINTS 1,X
40NEXT
50CLOSE1
Line10OPENs file 1 forWRITE as TESTFILE.
Line20Doeverything between "FOR"&"NEXT" 10times.
Line30PRINTS the variable 1 onto the tape.
Line40 Goesbackto line20 for10times.
Line50CLOSES the file.
Example program 2 — reading data using INPUT
10OPEN1,1,0,'TEST FILE"
20 INPUT#1,D$
30PRINT D$
40IFST=OGOT020
50CLOSE 1
Line10OPENS the file forREAD asTEST FILE.
Line20 Reads a string from the tape into D$.
Line 30Prints the value ofD$onthe screen.
Line40 Checks the status ofthe cassette. Ifthe tape isOK then GOTOline20.
Line 50CLOSESthe file.
Example program 3 — reading data usingGET
10OPEN1,1,0,'TEST FILE"
20GET#,1,D$
30PRINT D$
40 IFST=OGOT020
50CLOSE1
Line10OPENS the file for READ as TEST FILE.
Line20 GETsa character into D$.
Line30Prints the character invariable D$on the screen.
Line40 Checks the status of the cassette. Ifthe tape isOK then GOTOline 20.
Line50CLOSESthe file.

DATASSETTE™ PROBLEMS
Ifyou are experiencing problems withyour DATASSETTE™ either
mechanically or electronically, return it to the dealer fromwhom it was
purchased. Ifthe DATASSETTE™ isfaulty and inwarranty hewill replace itfor
you.