Cursor Up/Down key decreases the length value. The highest possible value is 975, and the lowest is 0.
PAUSE. You can enter a pause as easily as you enter any note. Use the space bar to enter pauses between notes; the length of the pause will be the same as the present note length. To enter longer or shorter pauses, change the LEN value as you did earlier.
When you enter pauses, you'll see that a space is dis played in the note column, and zeros are displayed in the LOWER and UPPER columns.
#. The # column shows the relative length of the notes entered. This is based on a unit of 25 as the basic increment of time. In other words, any note that has a length (LEN) of 25 will have a relative length of 1, a note that has a length (LEN) of 100 has a relative length of 4, and so on. This can help you determine the length to use in your notes if you are writing songs that have complex timing.
Playing music back. To play back the notes you have en tered at any point, all you need to do is press the f1 key. This will play all of the notes you have entered so far. You can use this function to check your timing, since the notes are played using the same timing and pauses you've entered.
Modifying the music. To change any note that you've entered, you need to delete the old note and enter the new one as you would enter any new note. The display table
shows you the last ten notes entered. To change a note, use * I
the Cursor Up/Down key (either SHIFTed or unSHIFTed) when the NOTE column is highlighted. By pressing the key
the correct number of times, you can position the note you I 1 want to delete at the bottom of the table in the upper half of
the screen. Unfortunately, this will delete all of the notes from - ■-, that entry number on up. What you're doing, in effect, is delet- LJ ing all the notes to that point. Once you press the Cursor Up/
Down key as a delete, the note is gone for good. If you keep : 60
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Music and the Sound Editor
pressing the key, you can erase your entire tune. Keep that in mind as you use it.
If you are beyond the tenth note in your song, the table will scroll backwards until it gets to the note you want to change. Remember that as the table scrolls backwards, what is really happening is that the notes are being erased.
Sharps and flats. In addition to the 14 notes obtained by pressing the appropriate keys, there are 10 other notes (called sharps or flats) that can be accessed by pressing the SHIFT key and a note key together. Figure 2-1 shows the positions of the sharps on the keyboard.
Figure 2-L Sharp Key Placement
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Notice that the sharps are C#, D#, F#, G# and A#. The notes E# and B# are not listed on this musical scale. This is because a sharp note is one that is half a step higher than the note it follows, and a flat is one-half step lower. Since the note F is half a step above E and the note B is half a step below C, there are no corresponding sharps or flats to display.
Figure 2-2 shows the positions of the flats available on the keyboard. Comparing this figure with Figure 2-1, you'll notice that the sharps and flats are accessed with the same keys. Remember that a sharp is a half step up, while a flat is a half step down. Thus Db is the same note as C#. When you select a flat, it will show in the table on the screen as a sharp.
To determine the flats, refer to the figure below.
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Music and the Sound Editor
Figure 2*2, Flat Key Positions
SAVEing music. To save a song that you have written on the sound editor, press the f3 key. You will then be asked if you wish to store the song on tape or disk. To save the song on tape, press T and hit RETURN. To store it on disk, press D, then press RETURN. The program will then ask you for the name you wish to store the song as. The name must be less than 16 characters long.
After the song has been stored, the computer will return to the edit screen and will be ready to accept a new song.
LOADing songs. To load a song that you have previously saved to disk or tape, press the f5 key. This will display a screen that is similar to the SAVE screen. By following the directions, you'll be able to load a song from either disk or tape. After the tape or disk drive begins to run, the edit screen will reappear, and the stored notes will be played and dis played on the screen as they are read into memory.
A few hints. If you're entering a large number of notes with the sound editor, there will be times when the last note key you pressed will stay highlighted. If you press any of the note keys, or even one of the function keys, nothing will hap pen. The computer hasn't locked up. There's nothing wrong.
The program is just taking some time to place all the values you've entered into the computer's memory. Wait patiently for the highlighted key to return to its normal display. Then you can continue to add more notes, or play the song, or save it to tape or disk. If you press a key while the last key is
high-62
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Music and the Sound Editor
lighted, that note will be read into memory once the program hands control back to you. It's a good idea to avoid pressing keys while the program is storing values; otherwise, it will read the keyboard buffer and place as many notes in the song as the number of times you hit that key. You'll have to delete those extra notes if that happens.
If you want to delete a note or notes, but still want a copy of the song as it exists, be sure to save it to tape or disk. Then when the screen returns, you can delete notes and listen to the new tune. If you don't like your alterations, at least you'll have a backup copy of the original version of the song on tape or disk. If you liked the original better, you can just load it and go on from there.
As the Sound Editor is listed, it uses the pulse waveform, with attack and sustain set to 0, the sustain/release control register set with a value of 240. You can change the waveform used by altering lines 1010 and 4440 in the program. Just change the value POKEd into location 54276. Adding an attack/decay value in line 3, where the program initializes several registers, would also change the sound of the notes as you enter them, as well as when you play back the entire song.