TRANSCRIPT FOR SID CLASS 11/22/87 The tempo determines how quickly a song at the beginning of a SID. The is the TEM command, and its default setting is 100 . The TEM command, voices. There are some restrictions on which tempo values can be used. The TEM command supports a limited number of tempo values, and some of those don't allow the use of certain note durations. If you are using the Enhanced Sid Editor, there is a built-in temp restriction chart; you can see this from the Command Screen by pressing "shift h". If you're not using the Enhanced Editor, it's a good idea to make a copy of the tempo restriction chart included in the book. The Enhanced Editor will also support sixty-fourth notes . However, with four tempos -- 225, 112, 75 and 56. Tempo values 81 and below do not allow the use of dotted whole notes, but this isn't a problem. Since a dotted note means to sustain that note its normal duration PLUS half, simply tie a half note onto the whole note to simulate a dotted whole. If you try to play durations in a tempo an "ILLEGAL DURATION" error. If this happens, press any key to acknowledge the error, then check each voice. The music will have stopped on the illegal note to pinpoint it for you. The only time you should set the TEM command on all three voices is when you change tempo in the middle of a song. The change must be made at a point where ALL THREE voices are beginning a new note. If possible, make the tempo change at the start of a measure. If the tempo change must occur in the middle of a measure, check carefully to be sure all three voices are beginning a new note, and set the TEM command at that point on all voices. There are ways to get around the tempo restrictions. You can use the UTL command to specify how many "jiffies" a note should play. A jiffy lasts about 1/60 of a second; the faster the tempo, the shorter the jiffy. The tempo restrictions chart will display the jiffy duration for each note in each tempo. Jiffy durations that are not displayed means that those notes are not allowed in that tempo value. If you are using a tempo value of 138, and the next higher or lower tempo simply will not work with your song BUT your sid contains sixteenth notes , here's what you do: a sixteenth note is one half of an eighth note, so check played at tempo 138. In this case, the it's not equally divisible, so you get an answer of 7 and 6. So, set the UTL command to 7 , go to the editing screen and press the "u" key. Instead of a note, you'll see "utility" displayed in the box. With your joystick or keyboard, put the note where it should be on the staff and hit return , and a "u" with the pitch and octave will be entered. If another sixteenth note is to be played in the same measure, its UTL value would be 6 <7+6=13>. If no other sixteenth note is played, then a UTL rest of 6 should be entered. Remember, you must keep the total jiffies in a measure consistant with all other measures. The UTL command is also used to enter "triplets". A sixteenth triplet means that three notes should be played in the amount of time as one eigth note. To do this, again check the jiffy duration of an eighth note for the particular tempo you're using. As an example, we'll use TEM 100, in which an eighth note plays for 12 jiffies. Divide 3 into 12; the answer is 4, so each note in the sixteenth triplet should play for 4 jiffies. Set the UTL command at 4 and enter the notes as earlier described. In some cases, though, you'll not get an equal number -- for instance, at first note of the triplet, set the UTL command at 2; then for the second note and third note of the triplet, the UTL command would be 3. The set UTL value remains in effect until changed. Beware: if you're using UTL command of UTL on one voice may affect the notes on another. So try to always use the same UTL setting on each voice. On sheet music, if you see a note that is smaller and written before another note, this is called a "grace note". A grace note is played quickly, just long enough to be heard. Use the UTL command to enter grace notes. There is judgement. However, remember that most must borrow from the PRECEEDING note for the grace note. Example: using TEM 100, enter a quarter note followed by a graced quarter note. At TEM 100, a quarter note lasts for 24 jiffies, and we want the grace note to be 4 jiffies long. Enter the first quarter note, using the UTL value of 20. Then enter the grace note with a UTL value of 4, then enter the last quarter note as usual. As discussed earlier, a dot placed after a note means that the note duration should be increased by one half. Sometimes you might see a note followed by TWO dots. This is a double extended the same amount as a dotted note PLUS half the value of the first dot. Example: a double dotted half note would be equal to a half note, a quarter note and an eighth note -- tied together. The Enhanced Editor supports double dotted notes; however, this is an "enhanced" command not supported by public domain players. If you do not wish to use this command, the double dotted note duration. Another "enhanced" command not supported by current public domain players is the double sharp or double flat command. If you do not wish to use the command, you must calculate the pitch that should be entered. For instance, if you encounter a C-double-sharp, you should enter a D-natural. By now, you should be able to enter an entire song with little difficulty. Please, if you upload any of your work, sure I include them in my library. Next week, we'll cover more advanced music theory and envelopes, including pulse sweep and portamento, and filter settings. :)