Backtrack v4.02 by Delta Force [web]
BACKTRACK¿ v4.02
by Karl Anders ²ygard
Copyright ½ 1992, Delta Force. All Rights Reserved
This program may be distributed without charge, provided that this text
file is present and that it and the program files are unmodified.
-- Overview ----------------------------------------------------------
BackTrack¿ is an program that will play any standard >Soundtracker 2.2
or Pro/Noisetracker module in the background (in a multitasking
fashion). The program may also be run as an accessory.
-- Installation ------------------------------------------------------
BackTrack¿ may be installed either as an accessory or a program,
depending on the extension of the program name. If you wish to use it
as an accessory, rename BackTrack¿ to BACKTRAK.ACC, place it at the
root of your bootdrive and make a reset. BackTrack¿ will automatically
appear in the menubar, ready for use.
If you wish to use BackTrack¿ as a program, rename it BACKTRAK.PRG.
Running as a program, BackTrack¿ is really only useful running under
MultiTOS.
-- Usage -------------------------------------------------------------
To load a module and play it, click 'LOAD' once. The fileselector will
pop up and you may choose a module. Sufficient memory will be allocated
and the module will be loaded. Unless something goes wrong, control
will be returned to BackTrack¿ with the module playing in the back-
ground.
To stop playing the module, click 'KILL' once. Playing will be
discontinued and memory is released.
To pause and restart sound, press the 'PAUSE' and 'PLAY' buttons,
respectively.
The playback frequency can be controlled by clicking the '6.259 kHz',
'12.517 kHz', '25.036 kHz' or '50.072 kHz' buttons. Upon clicked,
playback will immediately set to the corresponding frequency. Higher
frequency gives better sound, but requires more processor time.
BackTrack also has a Multiplex mode. This mode implies some pretty
clever cheating, and was first introduced to me by Jarle Kloppbakken of
Imagina. It speeds up playback vastly, but also introduces some very
high frequency noise. In my opinion, it is really only useful at the
50kHz mode. Multiplex mode may be toggled with the 'M/PLEX' button.
On an unexpanded 8MHz STe, the timings are somewhat like this:
Normal mode:
6.259 kHz - 15%, 12.517 kHz - 30%, 25.036 kHz - 60%, 50.072 kHz - 120%
Multiplex mode:
12.517 kHz - 15%, 25.036 kHz - 30%, 50.072 kHz - 60%
Note the 120% timing on 50kHz. Practically this means that this
frequency is inconceivable on a unexpanded 8MHz STe. Only if run on a
Mega STe or a TT will this frequency make sense.
When timings exceed 100%, the computer will skip ticks to prevent the
computer from crashing. When a lot of interrupts occur at the same
time, (i.e. the used moves the mouse manically around the screen etc.)
the accumulated timings _may_ exceed the magical limit, and the sound
scrapes a bit. This is especially true when running 25kHz on the 8MHz
STe. Selecting a frequency that is too high for your computer does not
harm anything, but it generally does not sound very nice.
-- Notes on memory management ----------------------------------------
Desk accessories should not allocate memory. However, I've been naughty
and not bothered about it. This trouble is that if you start playing a
module inside a program, the memory allocated will belong to the
program and not the accessory (this is not a bug in BackTrack, rather
than a "feature" from Atari). I can't be bothered to get around this
right now, so you'll just have to use your brain a little.
I may add that any accessories launched from Chameleon by K. Isakovic
allocates memory that belongs to the desktop. Thus, running BackTrack
from Chameleon fixes the aforementioned problem.
Running under MultiTOS, both accessories and program can allocate as
much memory as they please. Also, BackTrack supports memory protection,
and is perfectly well at home in a MultiTOS computer. For various
reasons it does not yet work on the Falcon computers. This will be
looked into as soon as I can get my hands on one.
-- Requirements ------------------------------------------------------
BackTrack¿ requires a DMA soundchip as featured in the STe and TT
computers. Thus, this program will *not* work on an ST. If there is
interest, I just *might* look into writing a version for the ST. (This
will most likely not feature the multitasking bit).
Also, if you would like to use the 50kHz option without multiplexing
mode on, you had better have a >8MHz STe (Mega STe or TT).
-- Disclaimer --------------------------------------------------------
This program may contain several bugs. It works nicely for me, but it
may turn *your* STe/TT into a toaster. Thus I cannot take any
responsibility for any harm done with or by this program. Use this
program at your own risk.
-- Donations? --------------------------------------------------------
This program is freeware. If you like it, send some cash or a couple of
High Quality disks to the author stating so. All requests cannot be
answered, but some bribing may help ;^) BackTrack may not be sold in a
public domain library unless the author gets a reasonable share of the
cake.
-- Buy! Buy! Buy! (Commercial break ;-) ------------------------------
ProTracker ST¿ v2.0 (formerly Esion XLII)
The ultimate music tool. Coming soon.
4 channels with separate volume control and frequency.
Realtime volume and pitch bending
Volume slide/Arpeggio/Vibrato/Portamento
6 - 50 (!) kHz playback frequency (STE)
4 - 50 kHz playback frequency (ST)
64KB sample buffer
Flexible editor with powerful cut and paste operations
(cut/copy/paste/transpose)
Polyphonic Midi support with realtime recording and touch control
Graphical easy to use sampleeditor
(cut/copy/paste/reverse/fade/boost/echo/mix)
Powerful sampler option
(sample/trig/resample/listen, frq. 4-32kHz)
Edit up to 32 songs simultaneously
Runs on any ST, STE, Mega STE and TT using low rez - 320x248 pixels
Intuitive graphical user interface
Compatible with ProTracker Amiga
... and bunches more.
Replay sources included:
8.2 kHz ST, uses regs. d5-d7/a6, 30% processor time
12.2 kHz ST, " " " , 50% " "
8.2 kHz ST, vol+pitch, uses regs. d5-d7/a6, 40% processor time
12.2 kHz ST, " " , " " " , 60% " "
12.5 kHz STE, uses no regs., 19% processor time
25.0 kHz STE, " " " , 38% " "
12.5 kHz STE, vol+pitch, uses no regs., 30% processor time
25.0 kHz STE, " " , " " " , 60% " "
----------------------------------------------------------------------
Happy listening,
Mail: Karl Anders ²ygard
Box 8
N-6180 SB²
Norway
Internet: Karl A Oygard <karloey@aahs.no>,
Karl A Oygard <karloey@unix1.mrih.no> or
"Wizzcat" on the IRC
Phone: +47 70 40015 (weekends only)
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