I want my AEX!
Analog sequencers go
to a new level
Atari-MIDI forum member
Guido Goebertus (also known as Dr Ambient), has created
an excellent application called AEX, which simulates
in an intelligent fashion, the analog sequencers of
yesteryear made famous by the works of Tangerine Dream,
the exploratory electronic music group. I have had the
pleasure of being beta tester, in which we completed
a working "beta" version, now released to
an unsuspecting Atari MIDI community. This is only the
beginning as we have big plans for AEX. Some ideas for
future versions include multiple AEX screens, some of
which are configured for bass and percussion, making
AEX a sort of Rebirth for Atari computers, but working
big news however: the Dr has been working steadily on
a new 256-color Falcon version, which is now ready for
release! This new version has many more improvements
as well as excellent graphics making full use of the
Falcon's color spectrum. A polished metal look and stunning
icons makes this application a real treat to use for
Falcon owners. The icons are not for show however; each
one has a different function. There are also more algorithms
as well as a transpose feature (using the numerical
keys), which makes changing keys a snap as well as striking.
The same updates have been added to the ST mono version.
See below for a MyAtari download! The zip contains both
algorithms instead of 10
These are accessed
using the [(] and [)] keys on the numeric keypad.
It is called the AEX index.
the global menu
mode allows for more of an algorithmic feel to the
in random rests, thus creating more interesting
allows you to set the MIDI channel for more control.
XG controllers: XG is the Yamaha standard
for GM, but brings it to a new level.
Transpose 0-12 semitones, using keys [Esc],
 to  and [+], which brings the key up a full
first opening AEX, you can see the screens are divided
into five main groups. By using the numeric keypad of
the computer keyboard you can access these screens.
A matter of point here: AEX is keyboard-driven, which
means there are no mouse actions available. However,
this makes for more of a real-time system as you go
quickly between screens and parameters and change them
on the fly while AEX is running. Here are the main keyboard
[)] and [/] toggle through the AEX index, which
creates variations in the sequence.
and [-] scroll through the parameters to make changes.
Lock] starts sequence
bar stops sequence
saves pattern (remember to put in .AEX as an extension
in order to save it correctly)
keys scroll through the screen options (or cells)
going from icon to icon or cell to cell in the Pattern
(0-12 semitones), using keys [Esc,]  to  and
[+], which brings the key up a full octave.
[Caps lock] to start AEX. Now hit . You are now
on the scale screen.
the [+] and [-] keys, change F_5 to C_4. Hit [Enter]
(not [Return]) to transact the change. Now using
the [(] and [)] keys, change the AEX index to 9.
Hit [Enter]. You will hear a change within the sequence.
play with the AEX index a bit and change it to 1,
then 2, then 3 and so on, hitting [Enter] as you
go. You will hear changes within the sequence as
it is running. This is very much a real time feature.
now is a description of the icons and their uses.
in this screen can all be changed by hand (by going
from parameter to parameter with the arrow keys), so
this is one way you can use AEX. However, AEX is also
set up to intelligently change these settings in an
automatic fashion with many variations. Parameters for
the actual notes
(velocity): the volume of each note
the stereo placement of each note.
an assignable continuous controller message
another assignable continuous controller message.
You can assign them on the Global screen (see below)
 on the
numeric keypad - makes up a simple AR envelope generator,
with five possible destinations. Icons (from left to
(start) level (0-127)
(1-5, where 1=key, 2=velocity, 3=panorama, 4=CC1,
Note: CC1 and CC2 are
freely assignable controllers, the controller type can
be set in the Global menu. In the DEF.AEX file they
are set to 74 and 71 (XG: cutoff frequency and resonance).
The logic menu
 on the numeric keypad
- a simulation of an LFO (low frequency oscillator),
which has also five possible destinations. There are
also differences, compared to a "normal" LFO:
a value of zero means no operation, a value of 1 will
affect every single entry, abd a value of 2 will affect
two successive entries, and so on. Icons (from left
- Destination (1-5,
same as the modulator)
The scale menu
 on the numeric keypad
- here is where the actual sequence is generated. There
are 32 algorithms available. These can be selected by
pressing the [(], [)] and [/] keys on the numeric keypad:
- [(] Value down
- [)] Value up
- [/] Random value
- Icon assignment:
1-5 for the actual "scale".
Note: as calculations
work from left to right, the first icon will in general
reflect the lowest note produced.
The global menu
 on the numeric keypad
- MIDI channel (1-16)
- Program change (0-127),
- CC1 (0-127)
- CC2 (0-127)
- Sub-voice (0-24
- Random playback
- Conductor: (0=Off,
Note: Random will pick
random note values from the "key" column,
instead of playing them one after another. The Conductor
mode looks if successive values in the key column are
equal, and if so only the first will sound. If both
random and conductor modes are switched on, AEX will
keep "composing" new sequences every cycle.
XG controllers from left
1: modulation depth
91: reverb depth
93: chorus depth
94: variation effect depth
73: attack time
72: release time
More on logic and
These screens allow you to create more variations, which
will affect whatever number is set in the last icon
parameter (the arrow going right), which is called the
"destination". Possible destinations are pulled
from the Patterns screen:
- Key (or note)
- Panorama (panning)
The best thing to do
is experiment with these algorithms to see what happens
to the music. Algorithms are represented by the graphs
looking much like an oscilloscope. Remember that when
you do a change, hit [Enter] to hear the change.
Use of CC1 and CC2
These are parameters settings
to adjust controller messages.For example, XG synths
use controllers 71 and 74 for filter frequency cutoff
and resonance. In the Global menu, set CC1 to 71 and
cc2 to 74 (icons 3 and 4, upper row). Then go to the
Modulator by pressing  and set destination to 4 for
CC1 or 5 for CC2.
The modulator parameters,
(icons 1 to 4) are:
- start value (0-127)
- attack time (0-32)
- attack value (0-127)
- release value (0-127)
This makes it possible
to make nice filter sweeps without the hassle of changing
all the values in the pattern editor. Of course, this
also works for other destinations like pan and so on.
In the Logic menu you
can do similar things: try a value of 4 for random (first
icon) and apply it to destination 4 or 5. This will
emulate the classic sample and hold effect.
It is possible to insert
- In the Logic menu,
third icon, destination 2 (velocity).
- In the pattern editor,
by setting velocity to zero.
Note values can be altered
in a number of ways:
- In the Scale/AEX
menu (where destination is fixed)
- In the Modulator
menu (not as useful)
- In the Logic menu,
set destination to 1
- In the pattern editor:
by using the [+] and [-] keys
I want my AEX
While there is
no official support for Atari computers, we are very
thankful for people like Guido Goebertus for continuing
to create quality programs for our platform. AEX sets
an example of what can be done in this new century on
a practical level as well as a creative one. Besides
being a programmer, the Dr is an excellent musician,
which is why his programs are well…so musical! Let every
Atari musician exclaim, "I want my AEX!"
ST and TT versions of the