FUTURE COMPOSER

Overview // 0x00

The program is a music editor for entering, arranging and playing back music data. The editor controls the Atari sound generators by giving the user three independent sound channels — this is achieved by combining sound generators 1 and 2 into one 16-bit channel. Channels 3 and 4 are not linked and allow playback of two independent motifs.

Main Menu Commands // 0x01

L, S — Load / Save

Saves and loads FC editor data. The saved data takes the form of files that are "understandable" only to the FC editor — they cannot be loaded into another music program. The disk version of the program contains example data on side B of the disk; these can be loaded into the editor and played. They have a name with the extension .FC, e.g. DRACONUS.FC.

E — Editor

Transition from the main menu into the editor.

C — Create

Generates a result module that can be embedded in any other program. The generated module contains both the playback procedure and the music data for that procedure.

The address at which the module will be placed in memory is set by adjusting the pointer to the first byte of the module. The pointer is adjusted with keys - and =. The module can be placed in the range $0400 to $FFFF − module length. After confirming the address with RETURN, you must enter the filename under which the module is to be saved.

N — New

Erases all editor data contained in FC. The contents of tracks, patterns, envelopes and sounds are cleared. All other parameters are set to their initial values.

D — Directory

Allows the disk catalog to be browsed. Use as in DOS.

Module Generation & STATUS Byte // 0x02

Playback initiation and procedure restart are controlled by the STATUS byte:

Action is selected the moment the corresponding bit is set. During normal playback, both bits are cleared.

For the playback procedure to operate correctly, it must be called 50 times per second. On every entry into the player, the STATUS register is tested and based on it the program continues execution.

Correct startup sequence

; ----------------------------------------
; Future Composer — start music from top
; ----------------------------------------
MODULE   =    $9000               ; load address chosen in C menu
RUN      =    MODULE               ; +$0000  GO pointer marker
PLAY     =    MODULE+1             ; +$0001  50 Hz tick entry
STATUS   =    MODULE+$030E         ; control byte
INIT     =    $9017                ; module-specific (saved by C-Create)

         lda  #3                   ; SKCTL guard (manual p.2)
         sta  $D20F
         lda  #0                   ; STATUS clear: normal play
         sta  STATUS
         jsr  INIT                 ; ONE-shot — separate from PLAY
; ...now call PLAY 50 Hz from VBI

The RUN marker contains the value of the GO pointer set in the FC editor. This marker must be set before calling the playback initialisation procedure. RUN is the address of the data in the track where the music we want to start playing begins. While saving the module, the RUN marker contains 0.

Editor System // 0x03

The FC editor consists of several sub-editors:

You can leave any editor at any time by pressing ESC.

Track Editor // 0x04

The data contained in tracks is the program for the music playback procedure. It contains data on sound transposition, the order in which patterns are played, and the end or repetition of the entire piece from the beginning.

Track command set

The maximum number of entries per single pattern is 256 (regardless of the type and number of commands).

Pattern Editor // 0x05

The pattern editor is used for defining and notating note sequences for the track editor.

Entry to the pattern editor occurs the moment the pattern cursor is set to a value identifying the pattern number and RETURN is pressed. If the pattern contains data, it is displayed in the PATTERN window. Where data is written is determined by the cursor.

Pattern editor commands

Sample piano (click any key to copy hex)

It is possible to enter 64 independent patterns, each containing up to 255 commands. You can move within patterns using the cursor keys.

Editor keys

Envelope Editor // 0x06

This editor allows you to determine the volume of a sound and to set its momentary distortion. Entry to the envelope editor is via the ^O key. The number of the edited envelope is shown by the OBW indicator. Change the edited envelope using - and =.

An envelope can contain up to 64 values, with its end marked by the .. sign. The values contained in the envelope determine the volume level with an accuracy of 1/50 sec.

Envelope structure

NR : XY-XY-XY-XY-XY-XY-XY-XY-XY-XY-XY-XY-XY-XY-XY-XY-XY-XY-XY

NR — number of the edited envelope value
X  — sound distortion (analogous values to those used with
     the SOUND instruction in BASIC). Values are entered
     simultaneously with pressing the SHIFT key.
Y  — volume level (0..F)

Visual demo (synthetic ADSR-style envelope)

It is possible to create and use up to 32 envelopes (range $00–$1F). Inside the envelope editor you can navigate using + and *. While the envelope is being created, a graphic representation of it is generated above the editor line.

Sound / Timbre Editor // 0x07

The sound editor allows you to determine the timbres of sounds defined by the SND instruction in the pattern editor. Entry to the sound editor is via the ^S key. The number of the edited sound is determined by the OBW indicator. Change the edited sound using - and =.

Editor format

01 : OB : ZG-AK-SW

(value from envelope) ORA (Z) = value written

Pattern Copying & Misc Editor Keys // 0x08

Copying patterns

Since copying patterns is often necessary, the COPY option (activated by pressing ^C) is provided. You then enter the number of the source pattern and the number of the destination pattern.

Other editor commands

Duration formula

duration = (SPEED × LEN) / 50  [seconds]

example: LEN.20 ($20 = 32) and SPEED = 8
         time = (8 × 32) / 50 = 5.12 sec

Function Keys // 0x09

00: 85 FF 00 00 00 00 00 00
08: 00 00 00 00 00 00 00 00

FC File Format (Save) // 0x0A

FC data save format via the S (Save) option:

Memory Map & Hardware // 0x0B

Zero-page usage by player

Module-relative offsets

Hardware registers

Module placement constraints

load address ∈ [$0400, $FFFF − module_length]
module is NOT relocatable — must be loaded at the address
chosen during creation in the C menu.

Quick Reference Card // 0x0C

All track commands

All editor entry hotkeys

Capacity limits

Minimal player init template

; ===========================================================
;  FUTURE COMPOSER 1.32 — corrected player wiring
;  matches actual C-Create module layout (verified vs SAP)
; ===========================================================
        opt   h-                 ; raw block, no Atari exe header
        org   $9000              ; <-- match address chosen in C menu
                                 ; module is NOT relocatable

MODULE  =     *
RUN     =     MODULE             ; +$0000  GO pointer marker (lo/hi)
PLAY    =     MODULE+1           ; +$0001  50 Hz tick entry
STATUS  =     MODULE+$030E       ; control byte (bit6=restart, bit7=pause)

; INIT is module-specific — get its address from C-Create save
; or from the SAP "INIT" line. NOT at a fixed offset.
INIT    =     $9017              ; <-- replace with your module's INIT

        ins   "music.bin"        ; raw FC module body

;-------------- one-shot init: call ONCE before VBI install -----
.proc   music_start
        lda   #3                 ; SKCTL guard (manual p.2)
        sta   $D20F
        lda   #0                 ; STATUS clear: normal play
        sta   STATUS
        jsr   INIT               ; <-- separate from PLAY
        rts
.endp

;-------------- 50 Hz tick: install on VVBLKD ($0224) -----------
.proc   music_tick
        jsr   PLAY               ; reads STATUS internally
        jmp   $E45F              ; XITVBV
.endp

;-------------- transport controls (set STATUS, take effect on
;               the next tick — the player polls STATUS) --------
.proc   music_restart            ; rewind track to top
        lda   #$40               ; bit 6
        sta   STATUS
        rts
.endp

.proc   music_pause              ; freeze playback
        lda   #$80               ; bit 7
        sta   STATUS
        rts
.endp

.proc   music_resume             ; clear both bits
        lda   #0
        sta   STATUS
        rts
.endp

Module Inspector // 0x0D

Drop a .sap, raw FC module, or Atari executable below. The inspector parses the file, locates PLAY / INIT / STATUS, decodes the STATUS byte live, and emits a ready-to-paste MADS template with the actual addresses filled in.