Sound, Music & MIDI Collection 2/SMMVOL2.bin/DOS/SS_PLAY/ST224.ZIP/INSTALL.005

Text File | 1990-10-10 | 5.1 KB | 144 lines

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 *******     Scream Tracker - Technical information     ********
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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.