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1993-03-19
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------- Tempo (playing speed)
To understand this completely, you need to know some technical aspects. MED
uses the CIAB timers for timing. They give "timing pulses" that trigger the
MED's player interrupt. On each timing pulse effects are handled (e.g.
commands 1,2,3,4,5,D, hold/decay, synthsounds), but new note is usually not
played on each pulse. The time between timing pulses can be changed
(primary tempo). The new note is usually played on every 6th pulse, but
this can be changed too (secondary tempo), for example, if new note was
played on every 3rd pulse, the playing speed would be twice as fast. This
doesn't affect the speed of effects.
Graphically:
pulse \ PLAY NOTE
the time between pulses can be changed (primary tempo)
pulse / DO EFFECTS \
\
pulse DO EFFECTS \ The number of pulses between
/ notes can be changed (4 in this example).
pulse DO EFFECTS / This is the secondary tempo.
/
pulse PLAY NOTE
...
+-------------------------------------------------------------------+
|+-----------------------------------------------------------------+|
|| MED V3.2 player commands/effects ||
|+-----------------------------------------------------------------+|
+-------------------------------------------------------------------+
This section gives information about commands/effects. They are events
which affect the playing and they are handled by the MED player routine.
C - 2 1 2 3 4
| \ |
command number \|
data byte
You insert the commands usually by hand (turn editing on, move cursor on the
command numbers and type the numbers). It may be a bit easier if you turn
off automatic-advance with Ctrl-A.
Here are the descriptions of each of the currently recognized commands:
+---------------------------------------------------+
| Command 0: ARPEGGIO MIDI: controller value |
+---------------------------------------------------+
This command changes the pitch of the note quickly (6 times during 1 note).
It can be used to create "chords" or special effects. If you've listened
to music made with the C-64, you MUST have heard arpeggios. The pitch is
changed between 3 different pitches during one note:
the 1st pitch is the pitch of the original note
the 2nd pitch is the pitch of the original note + the 1st number
of databyte halfsteps up
the 3rd pitch is the pitch of the original note + the 2nd number
of databyte halfsteps up
Note: 3rd pitch | 2nd pitch | 1st pitch | 3rd pitch | 2nd pitch | 1st pitch
changed 6 times during note
It may be a bit difficult to understand, so here's an example:
You want to make an arpeggio which sounds like C-major chord.
The lowest pitch is C (C-2 in this example).
The second is E-2 (4 halfsteps higher than C-2).
The third is G-2 (7 halfsteps higher than C-2).
4 halfsteps from C-2 -+ 7 halfsteps from C-2
|/
That produces: C-2 1047
--- 0047
--- 0047 and so on...
Data byte for a minor chord would be 37.
The arpeggios sound better with some instruments than others.
MIDI: See command 5 for a description.
+---------------------------------------------------+
| Command 1: SLIDE UP MIDI: pitchbender up |
+---------------------------------------------------+
This command slides up the pitch of the current track.
With Amiga samples:
Decreases the period of the note the amount of databyte on each
timing pulse. Sounds rather technical?? Yes... The instructions for
previous (before 2.10) versions of MED contained detailed
instructions for making good-sounding slides with this command.
Because this version now contains the easy automatic slide making
(Amiga-T), I felt that these instructions are not necessary any more.
If you use this function for special effects (not real slides) then
you can experiment with the values for the databyte.
Example:
A-1 1000
--- 0000
--- 010F <- slide up a bit
With MIDI:
This commands works very differently with MIDI. It actually
"turns" the pitchbender 8 * databyte steps up on each timing pulse.
Because the actual range of the pitchbender may be different with
different MIDI-devices, you must find the right value by
experimenting. There's also one thing you should know: when a new
note is played, the pitchbender is not resetted automatically. To
reset the pitchbender, you use this command with databyte zero.
Example:
G-2 L1FF <-turn it up very quick
--- 0000
--- 0100 <- then reset the pitchbender
+---------------------------------------------------+
| Command 2: SLIDE DOWN MIDI: pitchbender down |
+---------------------------------------------------+
Not much about this command. It's just like command 1 except it slides
down.
+---------------------------------------------------+
| Command 3: PORTAMENTO MIDI: set pitchbender |
+---------------------------------------------------+
This is another slide command (on some old MED versions (2.00) this
was a vibrato command, see command 5 now). It can be used to
make perfect slides more easily. First an example:
C-2 5000 <- played note C
--- 0000
E-2 5305 <- this note is not played!! Instead, slide target is set
--- 0300 to G-2 and slide speed is 5
--- 0300 <- when speed is zero, use the previous speed
--- 0306 <- the speed can be changed, of course
This example would slide from C-2 to E-2, but the slide stops EXACTLY
when E-2 is reached. The remaining 3's have no effect. This command
is easier to handle with automatic slide making (see Edit/S1 above).
MIDI: By using this command, you can set the pitchbender to an absolute
value, instead of sliding as commands 1 and 2 do. The data byte is the
pitchbender value, expressed as a signed hexadecimal digit (a nightmare
to non-programmers!).
00 = center position
80 (-7F) = smallest value
7F = largest value
Example:
C-2 3000
--- 037F <- pitchbender to max. value
--- 0300 <- reset
+---------------------------------------------------+
| Command 4: VIBRATO MIDI: modulation wheel |
+---------------------------------------------------+
The first number of the data byte is vibrato speed, the second is
vibrato depth. If the numbers are zeros, the previous speed and depth
is used.
Example: F-215000
--- 0000
--- 0433 <- slow, not much depth
--- 0437 <- more depth
--- 043F <- full depth
--- 0482 <- fast, not very deep
MIDI: This command affects the modulation wheel of the current channel.
The data byte can be 00 - 7F. 00 = no modulation, 7F = maximum.
Values 80 - FF are reserved for future expansion (and won't work).
+---------------------------------------------------+
| Command 5: OLD VIBRATO MIDI: controller number|
+---------------------------------------------------+
This is the old vibrato command (previously it was 3). The command 3 is
automatically converted to 5 when loading old MED songs. The pitch of
the note is changed between two values, databyte is the depth.
Example: A#1 J502
--- 0507 increasing depth
--- 0517 v
--- 0527
--- 0537
MIDI: Command 5 in conjunction with command 0 allows you to change any
controller of MIDI (command $Bx cc vv, where cc = controller number,
vv = value).
First you set the number of controller you want to change with command
5. Then you can select the value with command 0. Subsequent uses of
command 0 will affect the controller previously set with command 5.
Each channel has its own controller number. If the controller value is
$00, you can't use '00', because the command '000' means 'do nothing'.
Instead, you type '80'. Acceptable controller numbers and values are
$00 - $7F.
For example: (assuming instrument 3 is set to MIDI channel 1)
C-2 3000
--- 0507 <- controller $07, volume, according to MIDI standard
D-2 307F <- set max. volume ($7F), command $B0 $07 $7F is sent
--- 0000
F-3 3001 <- small volume ($01)
--- 055C <- select controller $5C (tremolo depth)
G-4 3080 <- set to 0 (note: $80 = $00)
+---------------------------------------------------+
| Command 8: SET HOLD/DECAY MIDI: set hold only |
+---------------------------------------------------+
This command must be located on the same line with a note. The command
assigns the hold and decay values for the note (see above for description
about hold/decay).
hold value
decay----------+|
||
Example: C-3 3824
-|- 3000
-|- 3000
--- 0000
+---------------------------------------------------+
| Command 9: SEC. TEMPO MIDI: no action |
+---------------------------------------------------+
This command sets the secondary tempo (the number of timing pulses/note).
The argument must be 01 - 20.
Example: --- 0903 <= double tempo
--- 0000
+---------------------------------------------------+
| Command A: VOLUME SLIDE MIDI: polyph aftertouch|
+---------------------------------------------------+
This is the same as command D (for Noise/Protracker compatibility).
However, please use D instead of this. If I some day find that there
are no free commands, I'll use this!!
MIDI: Command A changes the polyphonic aftertouch of the most recent note.
The value should be $00 - $7F.
Example:
C-3 4000
--- 0A30 <- aftertouch $30
--- 0000
--- 0A00 <- aftertouch $00
+---------------------------------------------------+
| Command B: POSITION JUMP MIDI: position jump |
+---------------------------------------------------+
This command lets you make songs that have beginning which is played
only once and then some part which is looped forever. Position jump
causes the jump to playsequence number pointed by the data byte. If the
data byte is 0, then the playseq jumps to the first entry.
Example: --- 0B02 <- start playing from playsequence number 3
+---------------------------------------------------+
| Command C: SET VOLUME MIDI: set volume |
+---------------------------------------------------+
You can override the default volume of the instrument with this command.
Example:
A-3 4C20 <- played with volume 20
There are 65 volume levels (0 - 64), 0 = no sound, 64 = maximum. The
data byte of command C can be 00 - 64 or 00 - 40 (decimal or hex).
Non-programmers will probably want to use the decimal numbers. See
(Play/[Dec/Hex]). If you want the playroutine to have maximum performance,
then use hex values.
It is also possible to change the volume of already played note. Note
that it doesn't work with MIDI-instruments.
Example:
A-3 4000
--- 0000
--- 0C10 <- volume to 10
It's possible to change the default volume of an instrument (MED V2 and
later). The value must be between 80 and C0 (always hex!). Value $80 = volume
0, and $C0 = 64. Note: This can cause trouble in multi-modules, because the
set of instruments (and their default volumes) are common. I recommend that
you change the default volume only on non-multi-modules.
+---------------------------------------------------+
| Command D: VOLUME SLIDE MIDI: channel pressure |
+---------------------------------------------------+
You can increase/decrease volume smoothly with this command. The data
byte is divided in two parts:
C-3 3D01
||
|+- Amount of decresdendo
+-- Amount of crescendo
If crescendo is zero, then the decrescendo is performed. Otherwise only
crescendo is performed.
Example:
C-2 3C40
--- 0D01 <- a bit more quiet
--- 0D01 <- even more
--- 0D20 <- and crescendo back to original
One unit in these commands means six actual volume units, so this example
would look like this, when using the C-command (except that it doesn't
sound so smooth):
C-2 3C40 (volumes are decimal in this example)
--- 0C34 <- -6
--- 0C28 <- -6
--- 0C40 <- +12
MIDI: This command sends a channel pressure (channel aftertouch) message
using the channel in which the most recent note was sent. The databyte
should be $00 - $7F.
D#5 J000
--- 0D40 <- channel aftertouch $40
--- 0D00 <- to $00
+---------------------------------------------------+
| Command E: SYNTH/JMP MIDI: pan control |
+---------------------------------------------------+
When used with synth/hybrid instruments, this command triggers a jump
in the waveform command sequence. The databyte is the jump destination
(line number).
Example: C-4 4000 <- this should be synth/hybrid instrument
--- 0000
--- 0E05 <- cause a jump to line # 5
With MIDI-instruments, this command controls the stereo location of the
sound. The data byte can be 00 - 7F.
left mid right
| | |
00 3F 7F
If you've used MED V2.00/V2.01 or Noise/SoundTracker, you may remember
that this command controlled the low-pass filter. I think that it was
unnecessary to spend the command E only for controlling only a single
switch. See command F.
+---------------------------------------------------+
| Command F: TEMPO/MISC. MIDI: tempo/misc. |
+---------------------------------------------------+
Command F has many different actions depending on the data byte.
If the data byte is zero (00), this command causes the immediate jumping
to the next block on the playing sequence (or to the beginning of this
block if you're only playing the block). This function is better to
implement by making the block shorter (takes less memory).
Example:
C-2 4F00 <- this is the last note of this block
When the data byte if 01 - F0, the command changes the tempo. This is the
primary tempo (length of the pause between timing pulses).
If the new tempo is 01 - 0A, it is compatible with Trackers, but now you
should use the command 9 instead of this command, as it's directly
Tracker-compatible (set the primary tempo to 33).
Example:
E-3 6FF0 <- highest tempo
--- 0000
--- 0F0B <- slowest
Data bytes FF1 - FFF are reserved for special actions, some of them
are currently used:
FF1 causes the same note played actually twice. This way it's possible
to create fast rhythms.
C-3 2FF1 is same as C-3 2000
C-3 2000 with double tempo
FF2 plays the note only once, but it is not started immediately:
C-3 2FF2 is same as --- 0000
C-3 2000 with double tempo
FF3 works like FF1 except the note is played three times (very fast).
FF8 turns off the low-pass filter (power-LED will dim).
FF9 turns the low-pass filter on (bright LED).
FFA sends MIDI "hold pedal on"-command (works only with MIDI-instruments).
FFB sends MIDI "hold pedal off"-command (works only with MIDI-instruments).
FFD works only with Amiga-samples. It causes the pitch of the channel to
be set to the pitch of the new note, but the new note is not replayed.
C-1 2000 <- play note
--- 0000
C-2 2FFD <- don't replay the note, just set the pitch to C-2
FFE stops playing immediately. If you want to make a song which plays only
once, put this command to the end of the song. This command can be
easily entered: Click "Stop playing" while holding the Shift-key.
FFF Stops the note on the current track. Works with both Amiga- and MIDI-
instruments. Nearly identical to "C00" on Amiga-samples, but because
"C00" doesn't work with MIDI, I made this command.