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Expander Performance Manual: Cassette Interface

The CASSETTE INTERFACE is used to store or retrieve programs from a cassette tape. Each program stored in the Expander's memory consists of a list of binary "words" called bytes. When storing a program on tape, the Expander's computer sends out the entire word list, adding in some dividers and markers to be used during reloading. To store all 50 voices, nearly 3,000 digital words are sent out in about 45 seconds.

Many tape recorders will work with the Expander. The optimum unit would be an ordinary, inexpensive, portable monophonic tape deck. It must have a microphone input Jack, a remote control jack (sometimes labelled REM), and a external speaker or earphone Jack. It also helps to have a tape counter. Cassette players with Auto Stop or Auto Reverse features should be avoided.

You will notice that the Cassette Interface Cord has three plugs; a long grey plug, a long black plug, and a short grey plug. The long black plug should be inserted in the audio output (EARPHONE) jack. The long grey plug should be inserted in the audio input (MICROPHONE) jack, and the short grey plug should be inserted in the remote control jack (it will not fit in any other jack).

For more details, see David Clarke's post Info on Chroma Cassette Cable in the January 2001 ChromaTalk mailing list archives.

Though nearly any audio cassette tape will work, it is best to select one that is likely to be free from flaws. A flawed tape will cause digital information to be lost, and will prevent the Expander from reading the information. Try to use the shorter tapes (30 minutes or less), because the tape is thicker and less prone to tangling or stretching. Use only fresh tapes if possible. Tapes made for personal computers marked "digital" or "certified" are usually a safe bet. Always observe the manufactures storage and handling instructions meticulously. It is always a good idea to keep a duplicate cassette stored in a safe place.


There are four switches on the left control panel for activating the cassette interface. They allow loading and saving of individual programs or loading and saving of all 50 programs. The four functions are as follows:

When you use one of these functions, the cassette player must then be manually placed in the PLAY or RECORD mode. The Expander will automatically stop the cassette recorder at the end of the operation. However, if at the point you wish to rewind or advance the tape, you must first press the STOP button on the tape deck. The Expander will detect operation, and relinquish control of the tape deck.

Any cassette operation can be aborted by pressing the STOP button on the tape deck, or by pressing one of the four CASSETTE INTERFACE panel switches on the Expander. In addition, if an error is detected during a load, the operation will halt, and 'Error' will be displayed in the DATA READOUT.


You will probably have to experiment to find the right settings for the volume control and tone controls (if any) on your tape deck. Start with the tone control set to full treble, and the volume on full. Reduce the volume a little with each attempt until the Expander reads the entire program without displaying an error. Mark the settings of the volume and tone controls on your tape deck for future reference.


Most cassette decks of this type have a fixed RECORD level. If your recorder has an AUTO LEVEL DEFEAT switch, you may want to experiment with different levels to obtain the best results. Once the best level has been found, you should always use the same level to record your programs.

The audio from the tape deck is automatically routed through the Expander's audio output. However, the Expander's computer only recognizes digital information. Therefore, it is possible to record through the cassette player's microphone spoken information about the programs to be stored. To use this feature, remove the Cassette Interface Cord from the tape deck, and record any message you wish. Then reconnect the cord to the deck and save the programs as described below.

[SAVE ONE] Switch

To save the current program, first place the tape deck in the RECORD mode, then press [SAVE ONE] on the Expander. The Expander will run the tape for a few seconds and then write out the current program on the tape. When it is finished, the Expander will stop the tape deck.

[SAVE ALL] Switch

The [SAVE ALL] switch is similar to the [SAVE ONE] switch, except that all 50 programs are stored instead of just the current program. Also, the LOCK/UNLOCK switch on the rear panel has an effect on the function of [SAVE ALL]. If [SAVE ALL] is used with the LOCK/UNLOCK switch in the UNLOCK position, the 50 programs will be stored with spaces between each program. This allows the programs to be loaded individually, and reduces the risk of losing a whole set of programs due to tape flaws since each program can he accessed individually.

If the [SAVE ALL] switch is used with the LOCK/UNLOCK switch in the LOCK position, all 50 programs will be stored together without spaces. This is the fastest method of storing and retrieving programs from cassette (185 seconds).


After using [SAVE ALL], press the STOP button on the tape deck and rewind to the beginning of the recording. With the LOCK/UNLOCK switch in the LOCK position, press [LOAD ALL]. The Expander will read each of the programs, but without putting them in memory. In this way, you can verify that the recording was error free. If an error occurs during this test, the Expander will stop the tape deck, and the DATA READOUT will say "Error.' This may indicate a flaw in the tape, in which case you will have to advance the tape to a new section and try to save the programs again. If this does not work, check your levels.

[LOAD ONE] Switch

To load one program from a cassette, set the tape deck to PLAY mode, and then press [LOAD ONE]. The Expander will start the tape and read a program from the tape into the "current program" workspace. The program may then be played or modified by the performer, but must be stored in a location for it to be retained in the Expander. See Editing: [STORE] Switch for information on the [STORE] function. Please note that the [LOAD DIE] function is only intended to work with tapes that have spaces between the programs. (See the descriptions of [SAVE ALL] above.)

[LOAD ALL] Switch

To load 50 programs at once, first put the LOCK/UNLOCK switch in the UNLOCK position. Then set the cassette recorder to PLAY mode, and press [LOAD ALL]. When the loading is complete, all 50 programs will be replaced with the programs from the tape.

CAUTION: Before loading all 50 programs from tape, you should first save the old programs in the Expander on another tape so that you do not lose them completely.