home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Mega A/V
/
mega_av.zip
/
mega_av
/
SOUNDUTL
/
ST224.ZIP
/
INSTALL.005
< prev
next >
Wrap
Text File
|
1990-10-10
|
5KB
|
144 lines
***************************************************************
******* ********
******* Scream Tracker - Technical information ********
******* ********
***************************************************************
Program protection:
The program's protection (the one displaying the
username in the topline) CAN be cracked, thus enabling
someone to enter any name on the line. Although the
topline info is NOT the only name information in the file!
In fact the name is encoded into over 10 places! Not all
of them are used in any way, so finding them is practically
impossible. So even if you manage to remove your name from the
topline, you can be sure that hidden owners inscription
is still there (at least a few of them)!
Sample storage on disk:
The samples used are stored to disk in 8 bit unsigned format.
(Amiga uses 8 bit signed format) To convert:
newbyte=(oldbyte+128) and 255.
VOXKIT samples:
If you have a soundblaster and have digitized voxkit samples
you can use them as instruments. Save samples in unpacked format
and remove the first 32 bytes (which form the header) from the
VOXKIT files.
Covox specification:
The Covox in setups means a device converting the printer ports
8 data lines to analog information (DA converter).
Informing about other output methods:
If you have knowledge of other PC cards/methods of outputting
8 bit digital sound, contact the author, and include a description
of the ouput method (Initialization and how to output a byte)
and the method will be added to new versions. REMARK that the
method must be a sequential byte at the time, and NOT for example
DMA, for sounds must be mixed in real time. See README for how
to contact the author.
File extension used with Scream Tracker:
.HLP - Help file
.STS - Scream Tracker song
.STM - Scream Tracker module
.ILB - Instrument library
.MOD - Amiga module
Scream Tracker program files:
ST.EXE - main program
ST.HLP - help file
ST.SET - saved setup
ST.ILB - main library (library names etc.)
STxx.ILB - libraries 00-99
Amiga conversion file extensions:
Amiga has 20 byte filenames, and PC only 8 byte ones. Due to this
fact amiga instrument names must be truncated to 8 chars. To avoid
confilict with for example BASSDRUM1 and BASSDRUM2 the converter
calculates an CRC of the entire amiga filename (chars added together)
and adds a CRC mod 512 to the files extension.
The examples would become: BASSDRUM.657 and BASSDRUM.658
Conversion differencies with amiga:
Volume Vibrato and Volume Portamento (NT 2.0) are converted
to funktions K and L, but have no effect in current version of
ST. The arpeggio command is now implemented.
Benchmarks:
The new ST enables using the Timer interrupt, so benchmarking
is now easier. With my machine (20Mhz 386SX) and ST playing
at 12Mhz, my benchmarks showed that ST used 60% of raw processing
power.
Playing frequencies:
The frequency listed is the frequency at which the samples
are mixed. The leftmost column describes the name for the
speed (in setup):
5Mhz AT - 5000Hz
6Mhz AT - 6500Hz
7Mhz AT - 8000Hz
8Mhz AT - 9943Hz
10Mhz AT - 11932Hz
11Mhz AT - 13000Hz
12Mhz AT - 15909Hz
16Mhz 386 - 17045Hz
20Mhz 386 - 19886Hz
23Mhz 386 - 23863Hz
Song/Module file structure:
Offset: Info:
0 Song/File name, max 20 chars, ASCIIZ, except if 20 chars long
20 Tracker name, max 8 chars, NO NUL
28 0x1A
29 File type: 1=song, 2=module
30 Version major (eg. 2)
31 Version minor (eg. 2)
32 byte; tempo
33 byte; num of patterns saved
34 byte; global volume
36 reserved, 13 bytes
48 Instruments (31 kpl) (see below) Instrument structure:
Offset Info
0 Inst. Filename, 12 bytes max, ASCIIZ
12 0x00
13 byte; instrument disk
14 word; reserved (used as internal segment while playing)
16 word; length in bytes
18 word; loop start
20 word; loop end
22 byte; volume
23 byte; reserved
24 word; speed for mid-C (in Hz)
26 reserved, 4 bytes
30 word; internal segment address/(in modules:)length in paragraphs
XXXX Music pattern orders (64 bytes/orders)
XXXX Patterns (number in header, each pattern 1KB)
Patterns consist of 64 rows, each 4 channels. Each channel
is 4 bytes in length, and the channels are stored from left
to right, row by row.
Special [BYTE0] contents:
251=last 3 bytes NOT in file, all bytes 0
252=last 3 bytes NOT in file, note: -0-
253=last 3 bytes NOT in file, note: ...
254=(in memory), -0-
255=(in memory), ...
otherwise:
note=[BYTE0] and 15 (C=0,C#=1,D=2...)
octave=[BYTE0] / 16
instrument=[BYTE1]/8
volume=([BYTE1] and 7)+[BYTE2]/2
command=[BYTE2] and 15
command info=[BYTE3]
[XXXX] In modules: Samples, padded to 16 byte limits. Sample lengths in
paragraphs (and as saved) are storen in instruments internal
segment address.