CHAPTER FOUR :
USING CASSETTE RECORDERS WITH YOUR TI99/4A
Emulators and Cassette Files
TI Emulate does NOT in any way emulate cassette handling.
The TI emulator in MESS emulates cassette files and saves / loads to WAV files.
PC99 will emulate cassette handling by loading and saving data to files on your hard disk.
Standard audio recorders provide an inexpensive method to store
your programs and data.
Due to modifications in the design of audio tape recorders, an
increasing number of them can be difficult to use with computers,
and TI have therefore produced a TI Recorder, designed for use
with the computer.
You may be able to use cheaper recorders, but you should try them
with program tapes recorded by someone else, before purchase.
For ease of operation, the tape recorder should have a tape
counter, and if you buy one with a tone control you may find it
easier to use.
The TI99/4A is designed for use with recorders having 3.5mm jack
sockets. Recorders with 5 pin DIN sockets may be unsuitable due to
the different input and output levels of these machines.
Always use a mains power supply for your cassette player, to
ensure the tape runs at the correct speed.
The magnetic particles on your tapes will pass on some of their
magnetism to your tape recorder heads : this in turn will slowly
wipe off your program. Regular use of a tape head cleaner and
demagnetiser is strongly recommended, usually a monthly clean and
demagnetisation are sufficient.
It is better to demagnetise before you notice any problems.
Similarly a build up of oxides will prevent your recorder from
picking up a proper signal, and may cause it to digest your tape.
Connecting your Recorder
You will usually be using only one tape recorder, and this is
connected using the lead with two 3.5mm jack plugs and one 2.5mm
jack plug. Plug the smaller plug into your recorders remote
control, the plug with the red wire into the microphone socket,
and the plug with the white wire into the earpiece socket.
The other end of the cable is a nine pin plug. This is connected
to the socket on the rear of the console : NOT the socket on the
left, which is for the joystick.
When the leads have been connected, press your cassette PLAY
button and check to see if the motor is running (the computer
console must be switched on). If the motor is silent, you will
need to use the polarity reversal adaptor supplied with the
cassette lead. This should ensure that your recorder now works. If
you experience difficulty, refer to your dealer.
You are now ready to record a program, or try loading a commercial
Loading a cassette Tape:
When your console has been connected to your tv and tape recorder,
and switched on, you may load a prerecorded program from tape.
Press a key to obtain the menu selection and then press key 1 to
obtain TI BASIC READY.
Now make sure the ALPHA LOCK key is DOWN, and key in:
OLD CS1 and press ENTER.
The computer will now give you instructions on what to do: First
rewind the tape and then press ENTER.
This is a good point at which to set your volume and, if you have
them, tone controls. Start with the volume control at the mid
point, and if available, set the tone control at maximum treble.
Now press cassette PLAY and then press ENTER. The tape should
start running (do you need the polarity reverser? see above).
The first part of the tape is a pilot tone, which is followed by
a fluctuating signal.
You may obtain an error message at this stage, which will
indicate that the volume is not set correctly.
NO DATA FOUND means that the volume is far too high, or far too
low (or the cassette recorder isn't connected).
ERROR IN DATA means the volume is not quite right. Make a note of
the tape counter setting when the tape stopped, then press R (to
Read) and follow the screen instructions. When the tape is
rewound, before you press PLAY again, make a small change in the
volume setting, then try again.
If you are again unlucky, see if the tape counter is now reading
a higher or lower figure. If it is higher, you need to move the
volume a little more in the same direction. If lower, move it in
the opposite direction - then try again.
Tape recorders vary in their success at matching the requirements
of the computer: on some it hardly seems to matter how you set the
volume, but on others the tape will only load at one setting.
Tapes recorded by someone else will usually need to be loaded at
a higher volume than your own, and may have a narrower range of
The reason for this difficulty is that tape recorders do not all
have their heads at exactly the same level, and with a tape
recorded on another machine, some of the signal will not be picked
up on your recorder. So you need a higher volume setting to make
up for this loss.
With a very few recorders you may find that your tape is running
at a speed which varies from that of the machine the tape was
recorded on, preventing the program loading. This is a very rare
problem but you may come across it.
When the tape is loaded, the computer will instruct you to press
cassette STOP then press ENTER. You will receive a DATA OK message
and after a short pause a flashing square will appear : this is
the cursor, and indicates the computer is ready for you to tell it
what to do.
You will want to RUN the program,so type in RUN and press ENTER.
The computer will take a few seconds to sort itself out but in due
course the program will be available for you to play.
When you only have the console, you may only run programs in TI
Basic. Trying to load or run programs in any other language (such
as Extended Basic) will produce error messages.
Saving programs to tape
When you have keyed in a program you may wish to save it on tape,
for future use. Otherwise you will have to key it all in again.
Use cassette tapes of maximum length C60. C90 tapes and longer
are thinner and liable to stretch slightly in use, distorting the
data the computer needs. Many large newsagents now sell computer
tapes of C10, C15 or C20 length. A C20 tape will hold three
average length programs on each side.
If you are keying in a long program,it is a good idea to save
your work from time to time, even though it is not finished, then
if some disaster occurs (such as baby brother unplugging your
console) you don't have to start all over again : you may load
your work and carry on from there.
When you are ready to save a program, type in SAVE CS1 (with the
alpha lock key down) and follow the directions which will appear
on the tv screen. When the computer has finished the recording,
you will be asked if you wish the tape to be checked : if your
program is worth recording, it is worth verifying the recording-
always respond Y (yes) you wish the tape to be checked. Then
follow screen directions.
This part of the procedure is the same as loading a tape, but
the computer will be checking the tape data against what it has in
memory. See the section on loading programs for further
The reason you should always check your recording is that even
the best tapes have small sections with little or no oxide
coating, causing what are termed 'drop outs', Very short duration
drop outs will not affect music, but you will lose some data. If
you find that your recording is unloadable for any reason, the
program is still in the computer, and you may use SAVE CS1 again
to try a different tape.
Please remember that tapes are relatively fragile so do not keep
them near to any strong electromagnetic field. In particular, it
is unwise to place a tape near to the console, the tv modulator,
or your tv set, for any length of time.
As tapes can be damaged so easily, always make two copies of
your program, on separate tapes. If one is damaged you can then
make a further backup from the second tape.
A magnetic tape has a limited life and you should rerecord onto
another tape if a tape begins to become difficult to load.
FURTHER NOTES ON USE OF SAVE:
The keys R C and E are used when an error has been found, to
R(ead) or R(ecord), C(heck), or E(xit). These keys are also active
whenever the current instruction is 'THEN PRESS ENTER'
Be careful not to press them unless you wish to Exit the
When you have finished recording a program, when the display
asks you to 'PRESS CASSETTE STOP THEN PRESS ENTER',
instead of pressing ENTER and moving on to the verify routine, you
may press R to immediately record the program again, say on
If you wish to save a program, and find on looking at the screen
the message 'PRESS CASSETTE PLAY THEN PRESS ENTER' you will
realise that instead of SAVE CS1, you have typed OLD CS1, and you
are well on your way to destroying all your hard work. You can
escape from this problem by pressing E. An error message may
appear, but your program should be safe.