Game 1 Unit 16 of 64 1 hr learning time
Phase 1 Complete
A complete rhythm game. Title screen, gameplay, win and lose. You built it.
25% of SID Symphony
You built a complete rhythm game. This unit celebrates that achievement.
From Unit 1’s first key press triggering sound, to this: a playable game with title screen, three-track gameplay, hit detection with timing windows, combo multipliers, health system, results screen, and game over handling. Hand it to a friend and watch them play SID Symphony.
Run It
Assemble and run:
acme -f cbm -o symphony.prg symphony.asm
Press fire to start. Hit notes as they reach the zone. Complete the song or run out of health trying.
What You Built
The complete Phase 1 game includes:
Visuals:
- Custom character set (notes, tracks, hit zone, bars)
- Three colour-coded tracks
- Score, miss count, combo, health, and progress displays
- Title screen with instructions
- Results screen with statistics
- Game over screen for failure
Audio:
- Three SID voices for note playback
- Distinct sounds for perfect and good hits
- Harsh noise for misses
- Menu click sounds
Gameplay:
- Hit detection with timing windows (perfect/good)
- Score multipliers based on combo (1x/2x/3x/4x)
- Health that rises on hits and falls on misses
- One complete song with 30+ notes
- Win condition (complete song)
- Lose condition (health depletes)
Flow:
- Title → Playing → Results/Game Over → Title
- Complete state machine with clean transitions
Phase 1 Journey
| Unit | Topic | What You Added |
|---|---|---|
| 1 | Hello SID | Tracks, keys trigger sounds |
| 2 | Notes Appear | Scrolling notes on beat |
| 3 | Making It Your Own | Customisation, learning by doing |
| 4 | Custom Graphics | Professional visuals |
| 5 | Hit Detection | Core gameplay works |
| 6 | Scoring | Points and visual feedback |
| 7 | Miss Handling | Consequences for failure |
| 8 | Health System | Stakes - game can be lost |
| 9 | Song Data | First complete song |
| 10 | Song Playback | Proper timing from data |
| 11 | Results Screen | Complete game loop |
| 12 | Combo System | Reward consistency |
| 13 | Title Screen | Proper presentation |
| 14 | Game Over Screen | Distinct failure state |
| 15 | Sound Polish | Complete audio feedback |
| 16 | Phase 1 Complete | Polished, balanced game |
Skills You’ve Learnt
6510 Assembly:
- Memory-mapped I/O (SID, VIC-II, CIA)
- Zero page addressing
- 16-bit arithmetic
- Keyboard matrix reading
- Data tables and pointers
SID Chip:
- Three voices with different waveforms
- ADSR envelope control
- Sound design for gameplay feedback
- Layering effects over music
Game Development:
- Game loop architecture
- State machine pattern
- Hit detection with timing windows
- Score and combo systems
- Health and game over handling
- UI layout and display
Balance Decisions
The game is tuned for fair difficulty:
; Timing windows - forgiving enough to learn
HIT_ZONE_MIN = 2 ; Early hit possible
HIT_ZONE_MAX = 5 ; Late hit possible
HIT_ZONE_CENTRE = 3 ; Perfect timing
; Health - misses hurt but not too much
HEALTH_MISS = 8 ; Lose 8 per miss
HEALTH_START = 32 ; Start half full
HEALTH_MAX = 64 ; Can recover fullyA new player can make several mistakes and still complete the song. An expert chases the perfect run.
The Complete Code
; ============================================================================
; SID SYMPHONY - Unit 16: Phase 1 Complete
; ============================================================================
; The complete Phase 1 rhythm game. Polished, balanced, and ready to play.
; Title screen, gameplay, results, game over - all working together.
;
; Controls: Z = Track 1 (high), X = Track 2 (mid), C = Track 3 (low)
; Fire/Space = Start game, return to title
; ============================================================================
; ============================================================================
; CUSTOMISATION SECTION
; ============================================================================
; SID Voice Settings (for note playback)
VOICE1_WAVE = $21 ; Sawtooth for track 1
VOICE2_WAVE = $41 ; Pulse for track 2
VOICE3_WAVE = $11 ; Triangle for track 3
VOICE1_FREQ = $1C
VOICE2_FREQ = $0E
VOICE3_FREQ = $07
VOICE_AD = $09 ; Attack=0, Decay=9
VOICE_SR = $00 ; Sustain=0, Release=0
PULSE_WIDTH = $08
; Perfect hit sound - bright and satisfying
PERFECT_SFX_FREQ = $30 ; Higher pitch
PERFECT_SFX_WAVE = $21 ; Sawtooth (bright)
PERFECT_SFX_AD = $08 ; Fast attack, medium decay
PERFECT_SFX_SR = $00 ; No sustain
; Good hit sound - positive but lesser
GOOD_SFX_FREQ = $20 ; Lower pitch than perfect
GOOD_SFX_WAVE = $11 ; Triangle (softer)
GOOD_SFX_AD = $0A ; Slightly slower decay
GOOD_SFX_SR = $00 ; No sustain
; Miss sound settings - harsh buzz
MISS_FREQ = $08
MISS_WAVE = $81 ; Noise
MISS_AD = $00 ; Instant attack
MISS_SR = $A0 ; Quick sustain, fast release
; Menu sound settings
MENU_SELECT_FREQ = $18 ; Menu click pitch
MENU_SELECT_WAVE = $41 ; Pulse for click
MENU_SELECT_AD = $00 ; Instant
MENU_SELECT_SR = $80 ; Very short
; Visual Settings
BORDER_COL = 0
BG_COL = 0
TRACK1_NOTE_COL = 10 ; Light red for high track
TRACK2_NOTE_COL = 13 ; Light green for mid track
TRACK3_NOTE_COL = 14 ; Light blue for low track
TRACK_LINE_COL = 11 ; Grey for track lines
HIT_ZONE_COL = 7 ; Yellow for hit zone
HIT_COL = 1
PERFECT_COL = 1 ; White flash for perfect
GOOD_COL = 7 ; Yellow flash for good
MISS_COL = 2 ; Red flash for miss
HEALTH_COL = 5 ; Green for health bar
PROGRESS_COL = 3 ; Cyan for progress bar
COMBO_COL = 13 ; Light green for combo
; Title screen colours
TITLE_COL = 1 ; White for title
SUBTITLE_COL = 11 ; Grey for subtitle
; ============================================================================
; SCORING SETTINGS (BALANCED)
; ============================================================================
PERFECT_SCORE = 100 ; Perfect hit value
GOOD_SCORE = 50 ; Good hit value
; ============================================================================
; COMBO SETTINGS (BALANCED)
; ============================================================================
COMBO_TIER_2 = 10 ; 2x multiplier at 10 hits
COMBO_TIER_3 = 25 ; 3x multiplier at 25 hits
COMBO_TIER_4 = 50 ; 4x multiplier at 50 hits
; ============================================================================
; HEALTH SETTINGS (BALANCED FOR FAIRNESS)
; ============================================================================
HEALTH_MAX = 64 ; Maximum health
HEALTH_START = 32 ; Start at half health
HEALTH_PERFECT = 4 ; Gain 4 for perfect
HEALTH_GOOD = 2 ; Gain 2 for good
HEALTH_MISS = 8 ; Lose 8 for miss (forgiving)
; ============================================================================
; HIT DETECTION SETTINGS (BALANCED TIMING WINDOWS)
; ============================================================================
HIT_ZONE_MIN = 2 ; Earliest hit column
HIT_ZONE_MAX = 5 ; Latest hit column
HIT_ZONE_CENTRE = 3 ; Perfect timing column
; ============================================================================
; SONG SETTINGS
; ============================================================================
SONG_LENGTH = 64 ; 64 beats at 120 BPM = ~32 seconds
PROGRESS_WIDTH = 16 ; Progress bar width
; ============================================================================
; GAME STATES
; ============================================================================
STATE_TITLE = 0 ; Title screen
STATE_PLAYING = 1 ; Gameplay
STATE_RESULTS = 2 ; Success results
STATE_GAMEOVER = 3 ; Failure game over
; ============================================================================
; MEMORY MAP
; ============================================================================
SCREEN = $0400
COLRAM = $D800
BORDER = $D020
BGCOL = $D021
CHARPTR = $D018
CHARSET = $3000
; SID registers
SID = $D400
SID_V1_FREQ_LO = $D400
SID_V1_FREQ_HI = $D401
SID_V1_PWHI = $D403
SID_V1_CTRL = $D404
SID_V1_AD = $D405
SID_V1_SR = $D406
SID_V2_FREQ_LO = $D407
SID_V2_FREQ_HI = $D408
SID_V2_PWHI = $D40A
SID_V2_CTRL = $D40B
SID_V2_AD = $D40C
SID_V2_SR = $D40D
SID_V3_FREQ_LO = $D40E
SID_V3_FREQ_HI = $D40F
SID_V3_PWHI = $D411
SID_V3_CTRL = $D412
SID_V3_AD = $D413
SID_V3_SR = $D414
SID_VOLUME = $D418
; CIA keyboard and joystick
CIA1_PRA = $DC00
CIA1_PRB = $DC01
; Track positions (balanced spacing)
TRACK1_ROW = 8 ; High track
TRACK2_ROW = 12 ; Mid track
TRACK3_ROW = 16 ; Low track
; HUD positions
HEALTH_ROW = 23 ; Health bar row
PROGRESS_ROW = 24 ; Progress bar row
; Combo display position
COMBO_ROW = 2 ; Combo display row
; Hit zone
HIT_ZONE_COLUMN = 3 ; Where notes are hit
; Custom character codes
CHAR_NOTE = 128
CHAR_TRACK = 129
CHAR_HITZONE = 130
CHAR_SPACE = 32
CHAR_BAR_FULL = 131
CHAR_BAR_EMPTY = 132
; Note settings
MAX_NOTES = 8 ; Maximum simultaneous notes
NOTE_SPAWN_COL = 37 ; Where notes appear
; Timing
FRAMES_PER_BEAT = 25 ; 50fps / 25 = 2 beats per second = 120 BPM
END_DELAY_FRAMES = 75 ; 1.5 seconds after song ends
; Zero page
ZP_PTR = $FB
ZP_PTR_HI = $FC
; Variables
frame_count = $02
beat_count = $03
song_pos = $04
song_pos_hi = $05
temp_track = $06
key_pressed = $07
hit_quality = $08
border_flash = $09
miss_track = $0A
game_state = $0B
hit_note_freq = $0C
song_beat = $0D
song_ended = $0E
end_delay = $0F
; ----------------------------------------------------------------------------
; BASIC Stub
; ----------------------------------------------------------------------------
* = $0801
!byte $0C, $08
!byte $0A, $00
!byte $9E
!text "2064"
!byte $00
!byte $00, $00
; ----------------------------------------------------------------------------
; Main Program
; ----------------------------------------------------------------------------
* = $0810
start:
jsr copy_charset
jsr init_sid
jsr show_title
; Start in TITLE state
lda #STATE_TITLE
sta game_state
main_loop:
lda #$FF
wait_raster:
cmp $D012
bne wait_raster
lda game_state
cmp #STATE_TITLE
beq do_title
cmp #STATE_PLAYING
beq do_playing
cmp #STATE_RESULTS
beq do_results
jmp do_gameover
do_title:
jsr update_title
jmp main_loop
do_playing:
jsr update_playing
jmp main_loop
do_results:
jsr update_results
jmp main_loop
do_gameover:
jsr update_gameover
jmp main_loop
; ----------------------------------------------------------------------------
; Show Title Screen
; ----------------------------------------------------------------------------
show_title:
; Clear screen
lda #BORDER_COL
sta BORDER
lda #BG_COL
sta BGCOL
ldx #0
lda #CHAR_SPACE
clear_title:
sta SCREEN,x
sta SCREEN+$100,x
sta SCREEN+$200,x
sta SCREEN+$2E8,x
inx
bne clear_title
; Draw big title "SID SYMPHONY"
ldx #0
draw_title_text:
lda title_big,x
beq draw_title_done
sta SCREEN + (8 * 40) + 14,x
lda #TITLE_COL
sta COLRAM + (8 * 40) + 14,x
inx
jmp draw_title_text
draw_title_done:
; Draw subtitle "A RHYTHM GAME"
ldx #0
draw_subtitle:
lda subtitle_text,x
beq draw_subtitle_done
sta SCREEN + (10 * 40) + 13,x
lda #SUBTITLE_COL
sta COLRAM + (10 * 40) + 13,x
inx
jmp draw_subtitle
draw_subtitle_done:
; Draw controls
ldx #0
draw_controls:
lda controls_text,x
beq draw_controls_done
sta SCREEN + (14 * 40) + 11,x
lda #11
sta COLRAM + (14 * 40) + 11,x
inx
jmp draw_controls
draw_controls_done:
; Draw track info
ldx #0
draw_track_info:
lda track_info,x
beq draw_track_done
sta SCREEN + (16 * 40) + 9,x
lda #11
sta COLRAM + (16 * 40) + 9,x
inx
jmp draw_track_info
draw_track_done:
; Draw "PRESS FIRE TO START"
ldx #0
draw_press_fire:
lda press_fire_text,x
beq draw_press_done
sta SCREEN + (20 * 40) + 10,x
lda #7 ; Yellow
sta COLRAM + (20 * 40) + 10,x
inx
jmp draw_press_fire
draw_press_done:
rts
title_big:
!scr "sid symphony"
!byte 0
subtitle_text:
!scr "a rhythm game"
!byte 0
controls_text:
!scr "controls: z / x / c"
!byte 0
track_info:
!scr "hit notes as they reach"
!byte 0
press_fire_text:
!scr "press fire to start"
!byte 0
; ----------------------------------------------------------------------------
; Update Title State
; ----------------------------------------------------------------------------
update_title:
; Check for fire button (joystick port 2)
lda CIA1_PRA
and #$10 ; Bit 4 = fire
beq fire_pressed
; Also check space bar as alternative
lda #$7F
sta CIA1_PRA
lda CIA1_PRB
and #$10 ; Space
beq fire_pressed
; No input - stay on title
lda #$FF
sta CIA1_PRA
rts
fire_pressed:
lda #$FF
sta CIA1_PRA
; Play menu select sound
jsr play_menu_select
; Start the game!
jsr init_game
lda #STATE_PLAYING
sta game_state
rts
; ----------------------------------------------------------------------------
; Play Menu Select Sound
; ----------------------------------------------------------------------------
play_menu_select:
lda #0
sta SID_V3_FREQ_LO
lda #MENU_SELECT_FREQ
sta SID_V3_FREQ_HI
lda #$08
sta SID_V3_PWHI
lda #MENU_SELECT_AD
sta SID_V3_AD
lda #MENU_SELECT_SR
sta SID_V3_SR
lda #MENU_SELECT_WAVE
ora #$01 ; Gate on
sta SID_V3_CTRL
rts
; ----------------------------------------------------------------------------
; Initialize Game (called when starting from title)
; ----------------------------------------------------------------------------
init_game:
jsr init_screen
jsr init_notes
jsr init_score
jsr init_health
jsr init_combo
jsr init_song
rts
; ----------------------------------------------------------------------------
; Initialize Combo
; ----------------------------------------------------------------------------
init_combo:
lda #0
sta combo
sta max_combo
jsr display_combo
rts
; ----------------------------------------------------------------------------
; Update Playing State
; ----------------------------------------------------------------------------
update_playing:
inc frame_count
lda frame_count
cmp #FRAMES_PER_BEAT
bcc no_new_beat
lda #0
sta frame_count
jsr advance_song
jsr check_spawn_note
no_new_beat:
jsr update_notes
jsr reset_track_colours
jsr update_border_flash
jsr check_keys
jsr check_song_end
rts
; ----------------------------------------------------------------------------
; Update Results State
; ----------------------------------------------------------------------------
update_results:
; Check for fire to return to title
lda CIA1_PRA
and #$10
beq results_fire
; Also check space bar
lda #$7F
sta CIA1_PRA
lda CIA1_PRB
and #$10
beq results_fire
lda #$FF
sta CIA1_PRA
rts
results_fire:
lda #$FF
sta CIA1_PRA
; Play menu select sound
jsr play_menu_select
; Return to title screen
jsr show_title
lda #STATE_TITLE
sta game_state
rts
; ----------------------------------------------------------------------------
; Update Game Over State
; ----------------------------------------------------------------------------
update_gameover:
; Check for fire to return to title
lda CIA1_PRA
and #$10
beq gameover_fire
lda #$7F
sta CIA1_PRA
lda CIA1_PRB
and #$10
beq gameover_fire
lda #$FF
sta CIA1_PRA
rts
gameover_fire:
lda #$FF
sta CIA1_PRA
; Play menu select sound
jsr play_menu_select
; Return to title screen
jsr show_title
lda #STATE_TITLE
sta game_state
rts
; ----------------------------------------------------------------------------
; Check Song End
; ----------------------------------------------------------------------------
check_song_end:
lda song_ended
beq song_not_ended
ldx #0
check_notes_clear:
lda note_track,x
bne notes_still_active
inx
cpx #MAX_NOTES
bne check_notes_clear
dec end_delay
bne song_not_ended
jsr show_results
lda #STATE_RESULTS
sta game_state
notes_still_active:
song_not_ended:
rts
; ----------------------------------------------------------------------------
; Initialize Song
; ----------------------------------------------------------------------------
init_song:
lda #<song_data
sta song_pos
lda #>song_data
sta song_pos_hi
lda #0
sta frame_count
sta beat_count
sta song_beat
sta border_flash
sta song_ended
lda #END_DELAY_FRAMES
sta end_delay
jsr display_progress
rts
; ----------------------------------------------------------------------------
; Advance Song
; ----------------------------------------------------------------------------
advance_song:
lda song_ended
bne advance_done
inc beat_count
inc song_beat
lda song_beat
cmp #SONG_LENGTH
bcc song_continues
lda #1
sta song_ended
song_continues:
jsr display_progress
advance_done:
rts
; ----------------------------------------------------------------------------
; Display Progress
; ----------------------------------------------------------------------------
display_progress:
lda song_beat
lsr
lsr
sta temp_progress
ldx #0
lda temp_progress
beq draw_empty_progress
draw_full_progress:
lda #CHAR_BAR_FULL
sta SCREEN + (PROGRESS_ROW * 40) + 12,x
lda #PROGRESS_COL
sta COLRAM + (PROGRESS_ROW * 40) + 12,x
inx
cpx temp_progress
bne draw_full_progress
draw_empty_progress:
cpx #PROGRESS_WIDTH
beq progress_done
lda #CHAR_BAR_EMPTY
sta SCREEN + (PROGRESS_ROW * 40) + 12,x
lda #11
sta COLRAM + (PROGRESS_ROW * 40) + 12,x
inx
jmp draw_empty_progress
progress_done:
rts
temp_progress: !byte 0
; ----------------------------------------------------------------------------
; Get Multiplier
; ----------------------------------------------------------------------------
get_multiplier:
lda combo
cmp #COMBO_TIER_4
bcs mult_4x
cmp #COMBO_TIER_3
bcs mult_3x
cmp #COMBO_TIER_2
bcs mult_2x
lda #1
rts
mult_2x:
lda #2
rts
mult_3x:
lda #3
rts
mult_4x:
lda #4
rts
; ----------------------------------------------------------------------------
; Display Combo
; ----------------------------------------------------------------------------
display_combo:
ldx #0
draw_combo_label:
lda combo_label,x
beq draw_combo_value
sta SCREEN + (COMBO_ROW * 40) + 12,x
lda #11
sta COLRAM + (COMBO_ROW * 40) + 12,x
inx
jmp draw_combo_label
draw_combo_value:
lda combo
ldx #0
combo_div_100:
cmp #100
bcc combo_done_100
sec
sbc #100
inx
jmp combo_div_100
combo_done_100:
pha
txa
ora #$30
sta SCREEN + (COMBO_ROW * 40) + 18
pla
ldx #0
combo_div_10:
cmp #10
bcc combo_done_10
sec
sbc #10
inx
jmp combo_div_10
combo_done_10:
pha
txa
ora #$30
sta SCREEN + (COMBO_ROW * 40) + 19
pla
ora #$30
sta SCREEN + (COMBO_ROW * 40) + 20
jsr get_multiplier
cmp #4
beq combo_col_4x
cmp #3
beq combo_col_3x
cmp #2
beq combo_col_2x
lda #11
jmp set_combo_col
combo_col_2x:
lda #7
jmp set_combo_col
combo_col_3x:
lda #5
jmp set_combo_col
combo_col_4x:
lda #1
set_combo_col:
sta COLRAM + (COMBO_ROW * 40) + 18
sta COLRAM + (COMBO_ROW * 40) + 19
sta COLRAM + (COMBO_ROW * 40) + 20
jsr get_multiplier
ora #$30
sta SCREEN + (COMBO_ROW * 40) + 22
lda #$18
sta SCREEN + (COMBO_ROW * 40) + 23
jsr get_multiplier
cmp #4
beq mult_col_4x
cmp #3
beq mult_col_3x
cmp #2
beq mult_col_2x
lda #11
jmp set_mult_col
mult_col_2x:
lda #7
jmp set_mult_col
mult_col_3x:
lda #5
jmp set_mult_col
mult_col_4x:
lda #1
set_mult_col:
sta COLRAM + (COMBO_ROW * 40) + 22
sta COLRAM + (COMBO_ROW * 40) + 23
rts
combo_label:
!scr "combo:"
!byte 0
; ----------------------------------------------------------------------------
; Increment Combo
; ----------------------------------------------------------------------------
increment_combo:
inc combo
lda combo
cmp max_combo
bcc combo_not_max
sta max_combo
combo_not_max:
jsr display_combo
rts
; ----------------------------------------------------------------------------
; Break Combo
; ----------------------------------------------------------------------------
break_combo:
lda combo
beq combo_already_zero
lda #0
sta combo
jsr display_combo
combo_already_zero:
rts
; ----------------------------------------------------------------------------
; Show Results Screen
; ----------------------------------------------------------------------------
show_results:
ldx #0
lda #CHAR_SPACE
clear_for_results:
sta SCREEN,x
sta SCREEN+$100,x
sta SCREEN+$200,x
sta SCREEN+$2E8,x
inx
bne clear_for_results
ldx #0
draw_results_title:
lda results_title,x
beq draw_results_title_done
sta SCREEN + (3 * 40) + 14,x
lda #1
sta COLRAM + (3 * 40) + 14,x
inx
jmp draw_results_title
draw_results_title_done:
ldx #0
draw_final_score_label:
lda final_score_label,x
beq draw_final_score_done
sta SCREEN + (6 * 40) + 10,x
lda #7
sta COLRAM + (6 * 40) + 10,x
inx
jmp draw_final_score_label
draw_final_score_done:
jsr display_final_score
ldx #0
draw_perfects_label:
lda perfects_label,x
beq draw_perfects_done
sta SCREEN + (8 * 40) + 10,x
lda #1
sta COLRAM + (8 * 40) + 10,x
inx
jmp draw_perfects_label
draw_perfects_done:
lda perfect_count
jsr display_stat_at_8
ldx #0
draw_goods_label:
lda goods_label,x
beq draw_goods_done
sta SCREEN + (9 * 40) + 10,x
lda #7
sta COLRAM + (9 * 40) + 10,x
inx
jmp draw_goods_label
draw_goods_done:
lda good_count
jsr display_stat_at_9
ldx #0
draw_misses_label:
lda misses_label,x
beq draw_misses_done
sta SCREEN + (10 * 40) + 10,x
lda #2
sta COLRAM + (10 * 40) + 10,x
inx
jmp draw_misses_label
draw_misses_done:
lda miss_count
jsr display_stat_at_10
ldx #0
draw_max_combo_label:
lda max_combo_label,x
beq draw_max_combo_done
sta SCREEN + (12 * 40) + 10,x
lda #13
sta COLRAM + (12 * 40) + 10,x
inx
jmp draw_max_combo_label
draw_max_combo_done:
lda max_combo
jsr display_stat_at_12
ldx #0
draw_accuracy_label:
lda accuracy_label,x
beq draw_accuracy_done
sta SCREEN + (14 * 40) + 10,x
lda #5
sta COLRAM + (14 * 40) + 10,x
inx
jmp draw_accuracy_label
draw_accuracy_done:
jsr calculate_accuracy
jsr display_accuracy
ldx #0
draw_press_key:
lda press_fire_results,x
beq draw_press_key_done
sta SCREEN + (18 * 40) + 9,x
lda #7
sta COLRAM + (18 * 40) + 9,x
inx
jmp draw_press_key
draw_press_key_done:
lda #5 ; Green border for success
sta BORDER
rts
results_title:
!scr "song complete!"
!byte 0
final_score_label:
!scr "final score:"
!byte 0
perfects_label:
!scr "perfects:"
!byte 0
goods_label:
!scr "goods:"
!byte 0
misses_label:
!scr "misses:"
!byte 0
max_combo_label:
!scr "max combo:"
!byte 0
accuracy_label:
!scr "accuracy:"
!byte 0
press_fire_results:
!scr "press fire for title"
!byte 0
; ----------------------------------------------------------------------------
; Display Final Score
; ----------------------------------------------------------------------------
display_final_score:
lda score_lo
sta work_lo
lda score_hi
sta work_hi
ldx #0
fs_div_10000:
lda work_lo
sec
sbc #<10000
tay
lda work_hi
sbc #>10000
bcc fs_done_10000
sta work_hi
sty work_lo
inx
jmp fs_div_10000
fs_done_10000:
txa
ora #$30
sta SCREEN + (6 * 40) + 23
ldx #0
fs_div_1000:
lda work_lo
sec
sbc #<1000
tay
lda work_hi
sbc #>1000
bcc fs_done_1000
sta work_hi
sty work_lo
inx
jmp fs_div_1000
fs_done_1000:
txa
ora #$30
sta SCREEN + (6 * 40) + 24
ldx #0
fs_div_100:
lda work_lo
sec
sbc #100
bcc fs_done_100
sta work_lo
inx
jmp fs_div_100
fs_done_100:
txa
ora #$30
sta SCREEN + (6 * 40) + 25
ldx #0
fs_div_10:
lda work_lo
sec
sbc #10
bcc fs_done_10
sta work_lo
inx
jmp fs_div_10
fs_done_10:
txa
ora #$30
sta SCREEN + (6 * 40) + 26
lda work_lo
ora #$30
sta SCREEN + (6 * 40) + 27
lda #7
sta COLRAM + (6 * 40) + 23
sta COLRAM + (6 * 40) + 24
sta COLRAM + (6 * 40) + 25
sta COLRAM + (6 * 40) + 26
sta COLRAM + (6 * 40) + 27
rts
; ----------------------------------------------------------------------------
; Display Stats
; ----------------------------------------------------------------------------
display_stat_at_8:
ldx #0
stat8_div:
cmp #10
bcc stat8_done
sec
sbc #10
inx
jmp stat8_div
stat8_done:
pha
txa
ora #$30
sta SCREEN + (8 * 40) + 23
pla
ora #$30
sta SCREEN + (8 * 40) + 24
lda #1
sta COLRAM + (8 * 40) + 23
sta COLRAM + (8 * 40) + 24
rts
display_stat_at_9:
ldx #0
stat9_div:
cmp #10
bcc stat9_done
sec
sbc #10
inx
jmp stat9_div
stat9_done:
pha
txa
ora #$30
sta SCREEN + (9 * 40) + 23
pla
ora #$30
sta SCREEN + (9 * 40) + 24
lda #7
sta COLRAM + (9 * 40) + 23
sta COLRAM + (9 * 40) + 24
rts
display_stat_at_10:
ldx #0
stat10_div:
cmp #10
bcc stat10_done
sec
sbc #10
inx
jmp stat10_div
stat10_done:
pha
txa
ora #$30
sta SCREEN + (10 * 40) + 23
pla
ora #$30
sta SCREEN + (10 * 40) + 24
lda #2
sta COLRAM + (10 * 40) + 23
sta COLRAM + (10 * 40) + 24
rts
display_stat_at_12:
ldx #0
stat12_div:
cmp #10
bcc stat12_done
sec
sbc #10
inx
jmp stat12_div
stat12_done:
pha
txa
ora #$30
sta SCREEN + (12 * 40) + 23
pla
ora #$30
sta SCREEN + (12 * 40) + 24
lda #13
sta COLRAM + (12 * 40) + 23
sta COLRAM + (12 * 40) + 24
rts
; ----------------------------------------------------------------------------
; Calculate Accuracy
; ----------------------------------------------------------------------------
calculate_accuracy:
lda perfect_count
clc
adc good_count
sta total_hits
clc
adc miss_count
sta total_notes
beq accuracy_zero
lda total_hits
sta dividend_lo
lda #0
sta dividend_hi
ldx #100
mult_loop:
dex
beq mult_done
lda dividend_lo
clc
adc total_hits
sta dividend_lo
lda dividend_hi
adc #0
sta dividend_hi
jmp mult_loop
mult_done:
lda #0
sta accuracy
div_loop:
lda dividend_lo
sec
sbc total_notes
tay
lda dividend_hi
sbc #0
bcc div_done
sta dividend_hi
sty dividend_lo
inc accuracy
jmp div_loop
div_done:
rts
accuracy_zero:
lda #0
sta accuracy
rts
total_hits: !byte 0
total_notes: !byte 0
dividend_lo: !byte 0
dividend_hi: !byte 0
accuracy: !byte 0
; ----------------------------------------------------------------------------
; Display Accuracy
; ----------------------------------------------------------------------------
display_accuracy:
lda accuracy
ldx #0
acc_div_100:
cmp #100
bcc acc_done_100
sec
sbc #100
inx
jmp acc_div_100
acc_done_100:
pha
txa
ora #$30
sta SCREEN + (14 * 40) + 23
pla
ldx #0
acc_div_10:
cmp #10
bcc acc_done_10
sec
sbc #10
inx
jmp acc_div_10
acc_done_10:
pha
txa
ora #$30
sta SCREEN + (14 * 40) + 24
pla
ora #$30
sta SCREEN + (14 * 40) + 25
lda #$25 ; % symbol
sta SCREEN + (14 * 40) + 26
lda #5
sta COLRAM + (14 * 40) + 23
sta COLRAM + (14 * 40) + 24
sta COLRAM + (14 * 40) + 25
sta COLRAM + (14 * 40) + 26
rts
; ----------------------------------------------------------------------------
; Copy Character Set
; ----------------------------------------------------------------------------
copy_charset:
sei
lda $01
pha
and #$FB
sta $01
ldx #0
copy_loop:
lda $D000,x
sta CHARSET,x
lda $D100,x
sta CHARSET+$100,x
lda $D200,x
sta CHARSET+$200,x
lda $D300,x
sta CHARSET+$300,x
lda $D400,x
sta CHARSET+$400,x
lda $D500,x
sta CHARSET+$500,x
lda $D600,x
sta CHARSET+$600,x
lda $D700,x
sta CHARSET+$700,x
inx
bne copy_loop
pla
sta $01
cli
jsr define_custom_chars
lda #$1C
sta CHARPTR
rts
; ----------------------------------------------------------------------------
; Define Custom Characters
; ----------------------------------------------------------------------------
define_custom_chars:
; Note character - arrow/chevron shape
lda #%00000110
sta CHARSET + (CHAR_NOTE * 8) + 0
lda #%00011110
sta CHARSET + (CHAR_NOTE * 8) + 1
lda #%01111110
sta CHARSET + (CHAR_NOTE * 8) + 2
lda #%11111110
sta CHARSET + (CHAR_NOTE * 8) + 3
lda #%11111110
sta CHARSET + (CHAR_NOTE * 8) + 4
lda #%01111110
sta CHARSET + (CHAR_NOTE * 8) + 5
lda #%00011110
sta CHARSET + (CHAR_NOTE * 8) + 6
lda #%00000110
sta CHARSET + (CHAR_NOTE * 8) + 7
; Track line character
lda #%00000000
sta CHARSET + (CHAR_TRACK * 8) + 0
sta CHARSET + (CHAR_TRACK * 8) + 1
sta CHARSET + (CHAR_TRACK * 8) + 2
lda #%11111111
sta CHARSET + (CHAR_TRACK * 8) + 3
sta CHARSET + (CHAR_TRACK * 8) + 4
lda #%00000000
sta CHARSET + (CHAR_TRACK * 8) + 5
sta CHARSET + (CHAR_TRACK * 8) + 6
sta CHARSET + (CHAR_TRACK * 8) + 7
; Hit zone character
lda #%01100110
sta CHARSET + (CHAR_HITZONE * 8) + 0
sta CHARSET + (CHAR_HITZONE * 8) + 1
sta CHARSET + (CHAR_HITZONE * 8) + 2
sta CHARSET + (CHAR_HITZONE * 8) + 3
sta CHARSET + (CHAR_HITZONE * 8) + 4
sta CHARSET + (CHAR_HITZONE * 8) + 5
sta CHARSET + (CHAR_HITZONE * 8) + 6
sta CHARSET + (CHAR_HITZONE * 8) + 7
; Full bar character
lda #%11111111
sta CHARSET + (CHAR_BAR_FULL * 8) + 0
sta CHARSET + (CHAR_BAR_FULL * 8) + 1
sta CHARSET + (CHAR_BAR_FULL * 8) + 2
sta CHARSET + (CHAR_BAR_FULL * 8) + 3
sta CHARSET + (CHAR_BAR_FULL * 8) + 4
sta CHARSET + (CHAR_BAR_FULL * 8) + 5
sta CHARSET + (CHAR_BAR_FULL * 8) + 6
sta CHARSET + (CHAR_BAR_FULL * 8) + 7
; Empty bar character
lda #%11111111
sta CHARSET + (CHAR_BAR_EMPTY * 8) + 0
lda #%10000001
sta CHARSET + (CHAR_BAR_EMPTY * 8) + 1
sta CHARSET + (CHAR_BAR_EMPTY * 8) + 2
sta CHARSET + (CHAR_BAR_EMPTY * 8) + 3
sta CHARSET + (CHAR_BAR_EMPTY * 8) + 4
sta CHARSET + (CHAR_BAR_EMPTY * 8) + 5
sta CHARSET + (CHAR_BAR_EMPTY * 8) + 6
lda #%11111111
sta CHARSET + (CHAR_BAR_EMPTY * 8) + 7
rts
; ----------------------------------------------------------------------------
; Initialize Health
; ----------------------------------------------------------------------------
init_health:
lda #HEALTH_START
sta health
jsr display_health
rts
; ----------------------------------------------------------------------------
; Initialize Score
; ----------------------------------------------------------------------------
init_score:
lda #0
sta score_lo
sta score_hi
sta miss_count
sta perfect_count
sta good_count
jsr display_score
jsr display_misses
rts
; ----------------------------------------------------------------------------
; Initialize Notes
; ----------------------------------------------------------------------------
init_notes:
ldx #MAX_NOTES-1
lda #0
init_notes_loop:
sta note_track,x
sta note_col,x
sta note_freq,x
dex
bpl init_notes_loop
rts
; ----------------------------------------------------------------------------
; Check Spawn Note
; ----------------------------------------------------------------------------
check_spawn_note:
lda song_ended
bne spawn_done_early
ldy #0
spawn_check_loop:
lda (song_pos),y
cmp #$FF
beq spawn_song_end
cmp beat_count
beq spawn_match
bcs spawn_done_early
jmp spawn_advance
spawn_match:
iny
lda (song_pos),y
sta temp_track
iny
lda (song_pos),y
pha
lda temp_track
jsr spawn_note_with_freq
pla
dey
dey
spawn_advance:
lda song_pos
clc
adc #3
sta song_pos
lda song_pos_hi
adc #0
sta song_pos_hi
jmp spawn_check_loop
spawn_song_end:
lda #1
sta song_ended
spawn_done_early:
rts
; ----------------------------------------------------------------------------
; Spawn Note With Frequency
; ----------------------------------------------------------------------------
spawn_note_with_freq:
sta temp_track
ldx #0
spawn_find_slot:
lda note_track,x
beq spawn_found_slot
inx
cpx #MAX_NOTES
bne spawn_find_slot
rts
spawn_found_slot:
lda temp_track
sta note_track,x
lda #NOTE_SPAWN_COL
sta note_col,x
tsx
lda $0103,x
sta note_freq,x
jsr draw_note
rts
; ----------------------------------------------------------------------------
; Update Notes
; ----------------------------------------------------------------------------
update_notes:
ldx #0
update_loop:
lda note_track,x
beq update_next
jsr erase_note
dec note_col,x
lda note_col,x
cmp #1
bcc update_miss
jsr draw_note
jmp update_next
update_miss:
lda note_track,x
sta miss_track
lda #0
sta note_track,x
jsr handle_miss
update_next:
inx
cpx #MAX_NOTES
bne update_loop
rts
; ----------------------------------------------------------------------------
; Handle Miss
; ----------------------------------------------------------------------------
handle_miss:
inc miss_count
jsr play_miss_sound
lda #MISS_COL
sta BORDER
lda #8
sta border_flash
jsr display_misses
jsr decrease_health
jsr break_combo
rts
; ----------------------------------------------------------------------------
; Decrease Health
; ----------------------------------------------------------------------------
decrease_health:
lda health
sec
sbc #HEALTH_MISS
bcc health_zero
sta health
jsr display_health
jsr check_game_over
rts
health_zero:
lda #0
sta health
jsr display_health
jsr check_game_over
rts
; ----------------------------------------------------------------------------
; Increase Health
; ----------------------------------------------------------------------------
increase_health:
clc
adc health
cmp #HEALTH_MAX
bcc health_ok
lda #HEALTH_MAX
health_ok:
sta health
jsr display_health
rts
; ----------------------------------------------------------------------------
; Check Game Over
; ----------------------------------------------------------------------------
check_game_over:
lda health
bne not_game_over
lda #STATE_GAMEOVER
sta game_state
jsr show_game_over
not_game_over:
rts
; ----------------------------------------------------------------------------
; Show Game Over
; ----------------------------------------------------------------------------
show_game_over:
; Clear screen for game over display
ldx #0
lda #CHAR_SPACE
clear_gameover:
sta SCREEN,x
sta SCREEN+$100,x
sta SCREEN+$200,x
sta SCREEN+$2E8,x
inx
bne clear_gameover
; Draw "GAME OVER" in red
ldx #0
game_over_loop:
lda game_over_text,x
beq game_over_text_done
sta SCREEN + (6 * 40) + 15,x
lda #2 ; Red for failure
sta COLRAM + (6 * 40) + 15,x
inx
jmp game_over_loop
game_over_text_done:
; Draw "HEALTH DEPLETED"
ldx #0
draw_depleted:
lda depleted_text,x
beq draw_depleted_done
sta SCREEN + (8 * 40) + 12,x
lda #10 ; Light red
sta COLRAM + (8 * 40) + 12,x
inx
jmp draw_depleted
draw_depleted_done:
; Show score achieved
ldx #0
draw_go_score_label:
lda go_score_label,x
beq draw_go_score_done
sta SCREEN + (12 * 40) + 11,x
lda #7
sta COLRAM + (12 * 40) + 11,x
inx
jmp draw_go_score_label
draw_go_score_done:
jsr display_gameover_score
; Show notes hit
ldx #0
draw_go_notes_label:
lda go_notes_label,x
beq draw_go_notes_done
sta SCREEN + (14 * 40) + 11,x
lda #11
sta COLRAM + (14 * 40) + 11,x
inx
jmp draw_go_notes_label
draw_go_notes_done:
lda perfect_count
clc
adc good_count
jsr display_go_stat
; "PRESS FIRE FOR TITLE"
ldx #0
game_over_press:
lda press_fire_gameover,x
beq game_over_done
sta SCREEN + (18 * 40) + 10,x
lda #7 ; Yellow for action
sta COLRAM + (18 * 40) + 10,x
inx
jmp game_over_press
game_over_done:
lda #2 ; Red border for failure
sta BORDER
rts
game_over_text:
!scr "game over"
!byte 0
depleted_text:
!scr "health depleted"
!byte 0
go_score_label:
!scr "score achieved:"
!byte 0
go_notes_label:
!scr "notes hit:"
!byte 0
press_fire_gameover:
!scr "press fire for title"
!byte 0
; Display gameover score (row 12)
display_gameover_score:
lda score_lo
sta work_lo
lda score_hi
sta work_hi
ldx #0
go_div_10000:
lda work_lo
sec
sbc #<10000
tay
lda work_hi
sbc #>10000
bcc go_done_10000
sta work_hi
sty work_lo
inx
jmp go_div_10000
go_done_10000:
txa
ora #$30
sta SCREEN + (12 * 40) + 27
ldx #0
go_div_1000:
lda work_lo
sec
sbc #<1000
tay
lda work_hi
sbc #>1000
bcc go_done_1000
sta work_hi
sty work_lo
inx
jmp go_div_1000
go_done_1000:
txa
ora #$30
sta SCREEN + (12 * 40) + 28
ldx #0
go_div_100:
lda work_lo
sec
sbc #100
bcc go_done_100
sta work_lo
inx
jmp go_div_100
go_done_100:
txa
ora #$30
sta SCREEN + (12 * 40) + 29
ldx #0
go_div_10:
lda work_lo
sec
sbc #10
bcc go_done_10
sta work_lo
inx
jmp go_div_10
go_done_10:
txa
ora #$30
sta SCREEN + (12 * 40) + 30
lda work_lo
ora #$30
sta SCREEN + (12 * 40) + 31
lda #7
sta COLRAM + (12 * 40) + 27
sta COLRAM + (12 * 40) + 28
sta COLRAM + (12 * 40) + 29
sta COLRAM + (12 * 40) + 30
sta COLRAM + (12 * 40) + 31
rts
; Display notes hit stat at row 14
display_go_stat:
ldx #0
go_stat_div:
cmp #10
bcc go_stat_done
sec
sbc #10
inx
jmp go_stat_div
go_stat_done:
pha
txa
ora #$30
sta SCREEN + (14 * 40) + 27
pla
ora #$30
sta SCREEN + (14 * 40) + 28
lda #11
sta COLRAM + (14 * 40) + 27
sta COLRAM + (14 * 40) + 28
rts
; ----------------------------------------------------------------------------
; Display Health
; ----------------------------------------------------------------------------
display_health:
lda health
lsr
lsr
lsr
sta temp_health
ldx #0
lda temp_health
beq draw_empty_bars
draw_full_bars:
lda #CHAR_BAR_FULL
sta SCREEN + (HEALTH_ROW * 40) + 12,x
lda #HEALTH_COL
sta COLRAM + (HEALTH_ROW * 40) + 12,x
inx
cpx temp_health
bne draw_full_bars
draw_empty_bars:
cpx #8
beq health_done
lda #CHAR_BAR_EMPTY
sta SCREEN + (HEALTH_ROW * 40) + 12,x
lda #11
sta COLRAM + (HEALTH_ROW * 40) + 12,x
inx
jmp draw_empty_bars
health_done:
rts
temp_health: !byte 0
; ============================================================================
; POLISHED SOUND EFFECTS
; ============================================================================
; Play Perfect Hit Sound - Bright, high, satisfying
play_perfect_sound:
lda #0
sta SID_V3_FREQ_LO
lda #PERFECT_SFX_FREQ
sta SID_V3_FREQ_HI
lda #$08
sta SID_V3_PWHI
lda #PERFECT_SFX_AD
sta SID_V3_AD
lda #PERFECT_SFX_SR
sta SID_V3_SR
lda #PERFECT_SFX_WAVE
ora #$01 ; Gate on
sta SID_V3_CTRL
rts
; Play Good Hit Sound - Positive but lesser
play_good_sound:
lda #0
sta SID_V3_FREQ_LO
lda #GOOD_SFX_FREQ
sta SID_V3_FREQ_HI
lda #$08
sta SID_V3_PWHI
lda #GOOD_SFX_AD
sta SID_V3_AD
lda #GOOD_SFX_SR
sta SID_V3_SR
lda #GOOD_SFX_WAVE
ora #$01 ; Gate on
sta SID_V3_CTRL
rts
; Play Miss Sound - Harsh buzz
play_miss_sound:
lda #0
sta SID_V3_FREQ_LO
lda #MISS_FREQ
sta SID_V3_FREQ_HI
lda #MISS_AD
sta SID_V3_AD
lda #MISS_SR
sta SID_V3_SR
lda #MISS_WAVE
ora #$01 ; Gate on
sta SID_V3_CTRL
rts
; ----------------------------------------------------------------------------
; Draw Note
; ----------------------------------------------------------------------------
draw_note:
lda note_track,x
cmp #1
beq draw_note_t1
cmp #2
beq draw_note_t2
cmp #3
beq draw_note_t3
rts
draw_note_t1:
lda note_col,x
clc
adc #<(SCREEN + TRACK1_ROW * 40)
sta ZP_PTR
lda #>(SCREEN + TRACK1_ROW * 40)
adc #0
sta ZP_PTR_HI
ldy #0
lda #CHAR_NOTE
sta (ZP_PTR),y
lda note_col,x
clc
adc #<(COLRAM + TRACK1_ROW * 40)
sta ZP_PTR
lda #>(COLRAM + TRACK1_ROW * 40)
adc #0
sta ZP_PTR_HI
lda #TRACK1_NOTE_COL
sta (ZP_PTR),y
rts
draw_note_t2:
lda note_col,x
clc
adc #<(SCREEN + TRACK2_ROW * 40)
sta ZP_PTR
lda #>(SCREEN + TRACK2_ROW * 40)
adc #0
sta ZP_PTR_HI
ldy #0
lda #CHAR_NOTE
sta (ZP_PTR),y
lda note_col,x
clc
adc #<(COLRAM + TRACK2_ROW * 40)
sta ZP_PTR
lda #>(COLRAM + TRACK2_ROW * 40)
adc #0
sta ZP_PTR_HI
lda #TRACK2_NOTE_COL
sta (ZP_PTR),y
rts
draw_note_t3:
lda note_col,x
clc
adc #<(SCREEN + TRACK3_ROW * 40)
sta ZP_PTR
lda #>(SCREEN + TRACK3_ROW * 40)
adc #0
sta ZP_PTR_HI
ldy #0
lda #CHAR_NOTE
sta (ZP_PTR),y
lda note_col,x
clc
adc #<(COLRAM + TRACK3_ROW * 40)
sta ZP_PTR
lda #>(COLRAM + TRACK3_ROW * 40)
adc #0
sta ZP_PTR_HI
lda #TRACK3_NOTE_COL
sta (ZP_PTR),y
rts
; ----------------------------------------------------------------------------
; Erase Note
; ----------------------------------------------------------------------------
erase_note:
lda note_track,x
cmp #1
beq erase_note_t1
cmp #2
beq erase_note_t2
cmp #3
beq erase_note_t3
rts
erase_note_t1:
lda note_col,x
clc
adc #<(SCREEN + TRACK1_ROW * 40)
sta ZP_PTR
lda #>(SCREEN + TRACK1_ROW * 40)
adc #0
sta ZP_PTR_HI
ldy #0
lda #CHAR_TRACK
sta (ZP_PTR),y
lda note_col,x
clc
adc #<(COLRAM + TRACK1_ROW * 40)
sta ZP_PTR
lda #>(COLRAM + TRACK1_ROW * 40)
adc #0
sta ZP_PTR_HI
lda #TRACK_LINE_COL
sta (ZP_PTR),y
rts
erase_note_t2:
lda note_col,x
clc
adc #<(SCREEN + TRACK2_ROW * 40)
sta ZP_PTR
lda #>(SCREEN + TRACK2_ROW * 40)
adc #0
sta ZP_PTR_HI
ldy #0
lda #CHAR_TRACK
sta (ZP_PTR),y
lda note_col,x
clc
adc #<(COLRAM + TRACK2_ROW * 40)
sta ZP_PTR
lda #>(COLRAM + TRACK2_ROW * 40)
adc #0
sta ZP_PTR_HI
lda #TRACK_LINE_COL
sta (ZP_PTR),y
rts
erase_note_t3:
lda note_col,x
clc
adc #<(SCREEN + TRACK3_ROW * 40)
sta ZP_PTR
lda #>(SCREEN + TRACK3_ROW * 40)
adc #0
sta ZP_PTR_HI
ldy #0
lda #CHAR_TRACK
sta (ZP_PTR),y
lda note_col,x
clc
adc #<(COLRAM + TRACK3_ROW * 40)
sta ZP_PTR
lda #>(COLRAM + TRACK3_ROW * 40)
adc #0
sta ZP_PTR_HI
lda #TRACK_LINE_COL
sta (ZP_PTR),y
rts
; ----------------------------------------------------------------------------
; Initialize Screen
; ----------------------------------------------------------------------------
init_screen:
lda #BORDER_COL
sta BORDER
lda #BG_COL
sta BGCOL
ldx #0
lda #CHAR_SPACE
clr_screen:
sta SCREEN,x
sta SCREEN+$100,x
sta SCREEN+$200,x
sta SCREEN+$2E8,x
inx
bne clr_screen
ldx #0
lda #TRACK_LINE_COL
clr_colour:
sta COLRAM,x
sta COLRAM+$100,x
sta COLRAM+$200,x
sta COLRAM+$2E8,x
inx
bne clr_colour
jsr draw_tracks
jsr draw_hit_zones
jsr draw_labels
rts
; ----------------------------------------------------------------------------
; Draw Tracks
; ----------------------------------------------------------------------------
draw_tracks:
lda #CHAR_TRACK
ldx #0
draw_t1:
sta SCREEN + (TRACK1_ROW * 40),x
inx
cpx #38
bne draw_t1
ldx #0
draw_t2:
sta SCREEN + (TRACK2_ROW * 40),x
inx
cpx #38
bne draw_t2
ldx #0
draw_t3:
sta SCREEN + (TRACK3_ROW * 40),x
inx
cpx #38
bne draw_t3
rts
; ----------------------------------------------------------------------------
; Draw Hit Zones
; ----------------------------------------------------------------------------
draw_hit_zones:
lda #CHAR_HITZONE
sta SCREEN + ((TRACK1_ROW-2) * 40) + HIT_ZONE_COLUMN
sta SCREEN + ((TRACK1_ROW-1) * 40) + HIT_ZONE_COLUMN
sta SCREEN + (TRACK1_ROW * 40) + HIT_ZONE_COLUMN
sta SCREEN + ((TRACK1_ROW+1) * 40) + HIT_ZONE_COLUMN
sta SCREEN + ((TRACK2_ROW-1) * 40) + HIT_ZONE_COLUMN
sta SCREEN + (TRACK2_ROW * 40) + HIT_ZONE_COLUMN
sta SCREEN + ((TRACK2_ROW+1) * 40) + HIT_ZONE_COLUMN
sta SCREEN + ((TRACK3_ROW-1) * 40) + HIT_ZONE_COLUMN
sta SCREEN + (TRACK3_ROW * 40) + HIT_ZONE_COLUMN
sta SCREEN + ((TRACK3_ROW+1) * 40) + HIT_ZONE_COLUMN
sta SCREEN + ((TRACK3_ROW+2) * 40) + HIT_ZONE_COLUMN
lda #HIT_ZONE_COL
sta COLRAM + ((TRACK1_ROW-2) * 40) + HIT_ZONE_COLUMN
sta COLRAM + ((TRACK1_ROW-1) * 40) + HIT_ZONE_COLUMN
sta COLRAM + (TRACK1_ROW * 40) + HIT_ZONE_COLUMN
sta COLRAM + ((TRACK1_ROW+1) * 40) + HIT_ZONE_COLUMN
sta COLRAM + ((TRACK2_ROW-1) * 40) + HIT_ZONE_COLUMN
sta COLRAM + (TRACK2_ROW * 40) + HIT_ZONE_COLUMN
sta COLRAM + ((TRACK2_ROW+1) * 40) + HIT_ZONE_COLUMN
sta COLRAM + ((TRACK3_ROW-1) * 40) + HIT_ZONE_COLUMN
sta COLRAM + (TRACK3_ROW * 40) + HIT_ZONE_COLUMN
sta COLRAM + ((TRACK3_ROW+1) * 40) + HIT_ZONE_COLUMN
sta COLRAM + ((TRACK3_ROW+2) * 40) + HIT_ZONE_COLUMN
rts
; ----------------------------------------------------------------------------
; Draw Labels
; ----------------------------------------------------------------------------
draw_labels:
ldx #0
draw_score_label:
lda score_label,x
beq draw_score_label_done
sta SCREEN + 1,x
lda #1
sta COLRAM + 1,x
inx
bne draw_score_label
draw_score_label_done:
ldx #0
draw_miss_label:
lda miss_label,x
beq draw_miss_label_done
sta SCREEN + 15,x
lda #2
sta COLRAM + 15,x
inx
bne draw_miss_label
draw_miss_label_done:
ldx #0
draw_title_game:
lda title_game,x
beq draw_title_game_done
sta SCREEN + 27,x
lda #1
sta COLRAM + 27,x
inx
bne draw_title_game
draw_title_game_done:
ldx #0
draw_health_label:
lda health_label,x
beq draw_health_label_done
sta SCREEN + (HEALTH_ROW * 40) + 4,x
lda #5
sta COLRAM + (HEALTH_ROW * 40) + 4,x
inx
bne draw_health_label
draw_health_label_done:
ldx #0
draw_progress_label:
lda progress_label,x
beq draw_progress_label_done
sta SCREEN + (PROGRESS_ROW * 40) + 4,x
lda #3
sta COLRAM + (PROGRESS_ROW * 40) + 4,x
inx
bne draw_progress_label
draw_progress_label_done:
lda #$1A ; Z label
sta SCREEN + (TRACK1_ROW * 40)
lda #TRACK1_NOTE_COL
sta COLRAM + (TRACK1_ROW * 40)
lda #$18 ; X label
sta SCREEN + (TRACK2_ROW * 40)
lda #TRACK2_NOTE_COL
sta COLRAM + (TRACK2_ROW * 40)
lda #$03 ; C label
sta SCREEN + (TRACK3_ROW * 40)
lda #TRACK3_NOTE_COL
sta COLRAM + (TRACK3_ROW * 40)
rts
score_label:
!scr "score:"
!byte 0
miss_label:
!scr "miss:"
!byte 0
title_game:
!scr "sid symphony"
!byte 0
health_label:
!scr "health:"
!byte 0
progress_label:
!scr "song:"
!byte 0
; ----------------------------------------------------------------------------
; Initialize SID
; ----------------------------------------------------------------------------
init_sid:
ldx #$18
lda #0
clear_sid:
sta SID,x
dex
bpl clear_sid
lda #$0F
sta SID_VOLUME
lda #$00
sta SID_V1_FREQ_LO
lda #VOICE1_FREQ
sta SID_V1_FREQ_HI
lda #PULSE_WIDTH
sta SID_V1_PWHI
lda #VOICE_AD
sta SID_V1_AD
lda #VOICE_SR
sta SID_V1_SR
lda #$00
sta SID_V2_FREQ_LO
lda #VOICE2_FREQ
sta SID_V2_FREQ_HI
lda #PULSE_WIDTH
sta SID_V2_PWHI
lda #VOICE_AD
sta SID_V2_AD
lda #VOICE_SR
sta SID_V2_SR
lda #$00
sta SID_V3_FREQ_LO
lda #VOICE3_FREQ
sta SID_V3_FREQ_HI
lda #PULSE_WIDTH
sta SID_V3_PWHI
lda #VOICE_AD
sta SID_V3_AD
lda #VOICE_SR
sta SID_V3_SR
rts
; ----------------------------------------------------------------------------
; Reset Track Colours
; ----------------------------------------------------------------------------
reset_track_colours:
ldx #0
lda #TRACK_LINE_COL
reset_t1:
sta COLRAM + (TRACK1_ROW * 40),x
inx
cpx #38
bne reset_t1
ldx #0
reset_t2:
sta COLRAM + (TRACK2_ROW * 40),x
inx
cpx #38
bne reset_t2
ldx #0
reset_t3:
sta COLRAM + (TRACK3_ROW * 40),x
inx
cpx #38
bne reset_t3
lda #TRACK1_NOTE_COL
sta COLRAM + (TRACK1_ROW * 40)
lda #TRACK2_NOTE_COL
sta COLRAM + (TRACK2_ROW * 40)
lda #TRACK3_NOTE_COL
sta COLRAM + (TRACK3_ROW * 40)
lda #HIT_ZONE_COL
sta COLRAM + (TRACK1_ROW * 40) + HIT_ZONE_COLUMN
sta COLRAM + (TRACK2_ROW * 40) + HIT_ZONE_COLUMN
sta COLRAM + (TRACK3_ROW * 40) + HIT_ZONE_COLUMN
jsr redraw_all_notes
rts
; ----------------------------------------------------------------------------
; Redraw All Notes
; ----------------------------------------------------------------------------
redraw_all_notes:
ldx #0
redraw_loop:
lda note_track,x
beq redraw_next
jsr draw_note
redraw_next:
inx
cpx #MAX_NOTES
bne redraw_loop
rts
; ----------------------------------------------------------------------------
; Update Border Flash
; ----------------------------------------------------------------------------
update_border_flash:
lda border_flash
beq flash_done
dec border_flash
bne flash_done
lda #BORDER_COL
sta BORDER
flash_done:
rts
; ----------------------------------------------------------------------------
; Check Keys
; ----------------------------------------------------------------------------
check_keys:
lda #$FD
sta CIA1_PRA
lda CIA1_PRB
and #$10
bne check_x_key
lda #1
sta key_pressed
jsr check_hit
bcc check_x_key
jsr play_voice1_note
jsr flash_track1_hit
jsr award_points
check_x_key:
lda #$FB
sta CIA1_PRA
lda CIA1_PRB
and #$80
bne check_c_key
lda #2
sta key_pressed
jsr check_hit
bcc check_c_key
jsr play_voice2_note
jsr flash_track2_hit
jsr award_points
check_c_key:
lda #$FB
sta CIA1_PRA
lda CIA1_PRB
and #$10
bne check_keys_done
lda #3
sta key_pressed
jsr check_hit
bcc check_keys_done
jsr play_voice3_note
jsr flash_track3_hit
jsr award_points
check_keys_done:
lda #$FF
sta CIA1_PRA
rts
; ----------------------------------------------------------------------------
; Check Hit
; ----------------------------------------------------------------------------
check_hit:
ldx #0
check_hit_loop:
lda note_track,x
beq check_hit_next
cmp key_pressed
bne check_hit_next
lda note_col,x
cmp #HIT_ZONE_MIN
bcc check_hit_next
cmp #HIT_ZONE_MAX+1
bcs check_hit_next
lda note_freq,x
sta hit_note_freq
lda note_col,x
cmp #HIT_ZONE_CENTRE
bcc hit_good
cmp #HIT_ZONE_CENTRE+2
bcs hit_good
lda #2
sta hit_quality
jmp hit_found
hit_good:
lda #1
sta hit_quality
hit_found:
jsr erase_note
lda #0
sta note_track,x
sec
rts
check_hit_next:
inx
cpx #MAX_NOTES
bne check_hit_loop
lda #0
sta hit_quality
clc
rts
; ----------------------------------------------------------------------------
; Award Points
; ----------------------------------------------------------------------------
award_points:
jsr increment_combo
lda hit_quality
cmp #2
beq award_perfect
; Good hit
lda #GOOD_SCORE
jsr apply_multiplier
jsr add_score
inc good_count
; Play good sound effect
jsr play_good_sound
lda #GOOD_COL
sta BORDER
lda #4
sta border_flash
lda #HEALTH_GOOD
jsr increase_health
jmp award_done
award_perfect:
; Perfect hit
lda #PERFECT_SCORE
jsr apply_multiplier
jsr add_score
inc perfect_count
; Play perfect sound effect
jsr play_perfect_sound
lda #PERFECT_COL
sta BORDER
lda #6
sta border_flash
lda #HEALTH_PERFECT
jsr increase_health
award_done:
jsr display_score
rts
; ----------------------------------------------------------------------------
; Apply Multiplier
; ----------------------------------------------------------------------------
apply_multiplier:
sta base_score
jsr get_multiplier
sta current_mult
lda base_score
sta score_add_lo
lda #0
sta score_add_hi
lda current_mult
cmp #1
beq mult_done_apply
dec current_mult
mult_add_loop:
lda score_add_lo
clc
adc base_score
sta score_add_lo
lda score_add_hi
adc #0
sta score_add_hi
dec current_mult
bne mult_add_loop
mult_done_apply:
rts
base_score: !byte 0
current_mult: !byte 0
score_add_lo: !byte 0
score_add_hi: !byte 0
; ----------------------------------------------------------------------------
; Add Score
; ----------------------------------------------------------------------------
add_score:
lda score_lo
clc
adc score_add_lo
sta score_lo
lda score_hi
adc score_add_hi
sta score_hi
rts
; ----------------------------------------------------------------------------
; Display Score
; ----------------------------------------------------------------------------
display_score:
lda score_lo
sta work_lo
lda score_hi
sta work_hi
ldx #0
div_10000:
lda work_lo
sec
sbc #<10000
tay
lda work_hi
sbc #>10000
bcc done_10000
sta work_hi
sty work_lo
inx
jmp div_10000
done_10000:
txa
ora #$30
sta SCREEN + 8
ldx #0
div_1000:
lda work_lo
sec
sbc #<1000
tay
lda work_hi
sbc #>1000
bcc done_1000
sta work_hi
sty work_lo
inx
jmp div_1000
done_1000:
txa
ora #$30
sta SCREEN + 9
ldx #0
div_100:
lda work_lo
sec
sbc #100
bcc done_100
sta work_lo
inx
jmp div_100
done_100:
txa
ora #$30
sta SCREEN + 10
ldx #0
div_10:
lda work_lo
sec
sbc #10
bcc done_10
sta work_lo
inx
jmp div_10
done_10:
txa
ora #$30
sta SCREEN + 11
lda work_lo
ora #$30
sta SCREEN + 12
lda #7
sta COLRAM + 8
sta COLRAM + 9
sta COLRAM + 10
sta COLRAM + 11
sta COLRAM + 12
rts
; ----------------------------------------------------------------------------
; Display Misses
; ----------------------------------------------------------------------------
display_misses:
lda miss_count
ldx #0
miss_div_10:
cmp #10
bcc miss_done_10
sec
sbc #10
inx
jmp miss_div_10
miss_done_10:
pha
txa
ora #$30
sta SCREEN + 21
pla
ora #$30
sta SCREEN + 22
lda #2
sta COLRAM + 21
sta COLRAM + 22
rts
work_lo: !byte 0
work_hi: !byte 0
; ----------------------------------------------------------------------------
; Play Voices (for note playback)
; ----------------------------------------------------------------------------
play_voice1_note:
lda #0
sta SID_V1_FREQ_LO
lda hit_note_freq
sta SID_V1_FREQ_HI
lda #VOICE1_WAVE
ora #$01
sta SID_V1_CTRL
rts
play_voice2_note:
lda #0
sta SID_V2_FREQ_LO
lda hit_note_freq
sta SID_V2_FREQ_HI
lda #VOICE2_WAVE
ora #$01
sta SID_V2_CTRL
rts
play_voice3_note:
lda #0
sta SID_V3_FREQ_LO
lda hit_note_freq
sta SID_V3_FREQ_HI
lda #VOICE3_WAVE
ora #$01
sta SID_V3_CTRL
rts
; ----------------------------------------------------------------------------
; Flash Tracks
; ----------------------------------------------------------------------------
flash_track1_hit:
ldx #0
lda #HIT_COL
flash_t1h_loop:
sta COLRAM + (TRACK1_ROW * 40),x
inx
cpx #38
bne flash_t1h_loop
lda #1
sta COLRAM + (TRACK1_ROW * 40)
rts
flash_track2_hit:
ldx #0
lda #HIT_COL
flash_t2h_loop:
sta COLRAM + (TRACK2_ROW * 40),x
inx
cpx #38
bne flash_t2h_loop
lda #1
sta COLRAM + (TRACK2_ROW * 40)
rts
flash_track3_hit:
ldx #0
lda #HIT_COL
flash_t3h_loop:
sta COLRAM + (TRACK3_ROW * 40),x
inx
cpx #38
bne flash_t3h_loop
lda #1
sta COLRAM + (TRACK3_ROW * 40)
rts
; ============================================================================
; SONG DATA - First Song (Balanced for Phase 1)
; ============================================================================
; Format: beat, track (1-3), SID frequency high byte
; Note spacing provides learnable pattern with variety
; ============================================================================
song_data:
; Opening - gentle introduction
!byte 0, 1, $47 ; Beat 0: Track 1, high note
!byte 2, 2, $2C ; Beat 2: Track 2, mid note
!byte 4, 3, $11 ; Beat 4: Track 3, low note
; Build - add more notes
!byte 8, 1, $3B
!byte 10, 2, $27
!byte 12, 3, $13
; Complexity - overlapping patterns
!byte 16, 1, $35
!byte 17, 2, $2C
!byte 18, 1, $3B
!byte 20, 3, $16
; Theme repeats
!byte 24, 1, $47
!byte 26, 2, $35
!byte 28, 3, $11
; Variation
!byte 32, 2, $2F
!byte 34, 1, $4F
!byte 36, 3, $17
; Building intensity
!byte 40, 1, $58
!byte 42, 2, $2C
!byte 44, 3, $11
!byte 46, 2, $27
; Climax section
!byte 48, 1, $6A
!byte 49, 2, $35
!byte 50, 1, $58
!byte 52, 3, $1A
!byte 54, 2, $2F
; Resolution
!byte 56, 1, $47
!byte 58, 2, $2C
!byte 60, 3, $11
!byte 62, 1, $35
!byte $FF ; End marker
; ----------------------------------------------------------------------------
; Note Arrays
; ----------------------------------------------------------------------------
note_track:
!fill MAX_NOTES, 0
note_col:
!fill MAX_NOTES, 0
note_freq:
!fill MAX_NOTES, 0
; ----------------------------------------------------------------------------
; Game Variables
; ----------------------------------------------------------------------------
score_lo: !byte 0
score_hi: !byte 0
miss_count: !byte 0
perfect_count: !byte 0
good_count: !byte 0
health: !byte 0
combo: !byte 0
max_combo: !byte 0
; ============================================================================
; END OF SID SYMPHONY - PHASE 1 COMPLETE
; ============================================================================
Sharing Your Game
The game runs on real hardware. To share it:
- Copy
symphony.prgto a D64 disk image - Transfer to real floppy or SD2IEC
- Load and run on actual C64
Your friends can play what you built.
What’s Next: Phase 2
Phase 2 (Units 17-32) expands the foundation:
- Multiple songs with different tempos and patterns
- Difficulty levels (Easy/Normal/Hard)
- Practice mode for learning without failure
- Career mode with unlockable content
- Endless mode with procedural generation
- Advanced visuals (sprite effects, colour cycling)
- Statistics tracking (lifetime totals)
The same core loop, dramatically more content.
What You’ve Learnt
- Complete game development - All systems working together
- Polish and balance - Tuning for fair difficulty
- State machines - Managing complex game flow
- SID mastery - Three voices, effects, feedback
- 6510 proficiency - Memory, arithmetic, I/O
Congratulations
You built a rhythm game on the Commodore 64. It has professional presentation, satisfying gameplay, and complete audio-visual feedback. It’s something you can show people.
Phase 2 awaits. More songs. More features. More polish.
The SID Symphony is just beginning.
What Changed
Unit 15 → Unit 16
+81-70
| 1 | 1 | ; ============================================================================ | |
| 2 | - | ; SID SYMPHONY - Unit 15: Sound Polish | |
| 2 | + | ; SID SYMPHONY - Unit 16: Phase 1 Complete | |
| 3 | 3 | ; ============================================================================ | |
| 4 | - | ; Distinct sounds for hit qualities. Perfect hits sound bright and satisfying. | |
| 5 | - | ; Good hits are positive but lesser. Miss sounds are harsh. Menu sounds click. | |
| 4 | + | ; The complete Phase 1 rhythm game. Polished, balanced, and ready to play. | |
| 5 | + | ; Title screen, gameplay, results, game over - all working together. | |
| 6 | 6 | ; | |
| 7 | 7 | ; Controls: Z = Track 1 (high), X = Track 2 (mid), C = Track 3 (low) | |
| 8 | - | ; Fire = Start game from title screen | |
| 8 | + | ; Fire/Space = Start game, return to title | |
| 9 | 9 | ; ============================================================================ | |
| 10 | 10 | | |
| 11 | 11 | ; ============================================================================ | |
| ... | |||
| 53 | 53 | BORDER_COL = 0 | |
| 54 | 54 | BG_COL = 0 | |
| 55 | 55 | | |
| 56 | - | TRACK1_NOTE_COL = 10 | |
| 57 | - | TRACK2_NOTE_COL = 13 | |
| 58 | - | TRACK3_NOTE_COL = 14 | |
| 56 | + | TRACK1_NOTE_COL = 10 ; Light red for high track | |
| 57 | + | TRACK2_NOTE_COL = 13 ; Light green for mid track | |
| 58 | + | TRACK3_NOTE_COL = 14 ; Light blue for low track | |
| 59 | 59 | | |
| 60 | - | TRACK_LINE_COL = 11 | |
| 61 | - | HIT_ZONE_COL = 7 | |
| 60 | + | TRACK_LINE_COL = 11 ; Grey for track lines | |
| 61 | + | HIT_ZONE_COL = 7 ; Yellow for hit zone | |
| 62 | 62 | | |
| 63 | 63 | HIT_COL = 1 | |
| 64 | - | PERFECT_COL = 1 | |
| 65 | - | GOOD_COL = 7 | |
| 66 | - | MISS_COL = 2 | |
| 64 | + | PERFECT_COL = 1 ; White flash for perfect | |
| 65 | + | GOOD_COL = 7 ; Yellow flash for good | |
| 66 | + | MISS_COL = 2 ; Red flash for miss | |
| 67 | 67 | | |
| 68 | - | HEALTH_COL = 5 | |
| 69 | - | PROGRESS_COL = 3 | |
| 70 | - | COMBO_COL = 13 | |
| 68 | + | HEALTH_COL = 5 ; Green for health bar | |
| 69 | + | PROGRESS_COL = 3 ; Cyan for progress bar | |
| 70 | + | COMBO_COL = 13 ; Light green for combo | |
| 71 | 71 | | |
| 72 | 72 | ; Title screen colours | |
| 73 | 73 | TITLE_COL = 1 ; White for title | |
| 74 | 74 | SUBTITLE_COL = 11 ; Grey for subtitle | |
| 75 | 75 | | |
| 76 | 76 | ; ============================================================================ | |
| 77 | - | ; SCORING SETTINGS | |
| 77 | + | ; SCORING SETTINGS (BALANCED) | |
| 78 | 78 | ; ============================================================================ | |
| 79 | 79 | | |
| 80 | - | PERFECT_SCORE = 100 | |
| 81 | - | GOOD_SCORE = 50 | |
| 80 | + | PERFECT_SCORE = 100 ; Perfect hit value | |
| 81 | + | GOOD_SCORE = 50 ; Good hit value | |
| 82 | 82 | | |
| 83 | 83 | ; ============================================================================ | |
| 84 | - | ; COMBO SETTINGS | |
| 84 | + | ; COMBO SETTINGS (BALANCED) | |
| 85 | 85 | ; ============================================================================ | |
| 86 | 86 | | |
| 87 | - | COMBO_TIER_2 = 10 | |
| 88 | - | COMBO_TIER_3 = 25 | |
| 89 | - | COMBO_TIER_4 = 50 | |
| 87 | + | COMBO_TIER_2 = 10 ; 2x multiplier at 10 hits | |
| 88 | + | COMBO_TIER_3 = 25 ; 3x multiplier at 25 hits | |
| 89 | + | COMBO_TIER_4 = 50 ; 4x multiplier at 50 hits | |
| 90 | 90 | | |
| 91 | 91 | ; ============================================================================ | |
| 92 | - | ; HEALTH SETTINGS | |
| 92 | + | ; HEALTH SETTINGS (BALANCED FOR FAIRNESS) | |
| 93 | 93 | ; ============================================================================ | |
| 94 | 94 | | |
| 95 | - | HEALTH_MAX = 64 | |
| 96 | - | HEALTH_START = 32 | |
| 97 | - | HEALTH_PERFECT = 4 | |
| 98 | - | HEALTH_GOOD = 2 | |
| 99 | - | HEALTH_MISS = 8 | |
| 95 | + | HEALTH_MAX = 64 ; Maximum health | |
| 96 | + | HEALTH_START = 32 ; Start at half health | |
| 97 | + | HEALTH_PERFECT = 4 ; Gain 4 for perfect | |
| 98 | + | HEALTH_GOOD = 2 ; Gain 2 for good | |
| 99 | + | HEALTH_MISS = 8 ; Lose 8 for miss (forgiving) | |
| 100 | 100 | | |
| 101 | 101 | ; ============================================================================ | |
| 102 | - | ; HIT DETECTION SETTINGS | |
| 102 | + | ; HIT DETECTION SETTINGS (BALANCED TIMING WINDOWS) | |
| 103 | 103 | ; ============================================================================ | |
| 104 | 104 | | |
| 105 | - | HIT_ZONE_MIN = 2 | |
| 106 | - | HIT_ZONE_MAX = 5 | |
| 107 | - | HIT_ZONE_CENTRE = 3 | |
| 105 | + | HIT_ZONE_MIN = 2 ; Earliest hit column | |
| 106 | + | HIT_ZONE_MAX = 5 ; Latest hit column | |
| 107 | + | HIT_ZONE_CENTRE = 3 ; Perfect timing column | |
| 108 | 108 | | |
| 109 | 109 | ; ============================================================================ | |
| 110 | 110 | ; SONG SETTINGS | |
| 111 | 111 | ; ============================================================================ | |
| 112 | 112 | | |
| 113 | - | SONG_LENGTH = 64 | |
| 114 | - | PROGRESS_WIDTH = 16 | |
| 113 | + | SONG_LENGTH = 64 ; 64 beats at 120 BPM = ~32 seconds | |
| 114 | + | PROGRESS_WIDTH = 16 ; Progress bar width | |
| 115 | 115 | | |
| 116 | 116 | ; ============================================================================ | |
| 117 | 117 | ; GAME STATES | |
| 118 | 118 | ; ============================================================================ | |
| 119 | 119 | | |
| 120 | - | STATE_TITLE = 0 | |
| 121 | - | STATE_PLAYING = 1 | |
| 122 | - | STATE_RESULTS = 2 | |
| 123 | - | STATE_GAMEOVER = 3 | |
| 120 | + | STATE_TITLE = 0 ; Title screen | |
| 121 | + | STATE_PLAYING = 1 ; Gameplay | |
| 122 | + | STATE_RESULTS = 2 ; Success results | |
| 123 | + | STATE_GAMEOVER = 3 ; Failure game over | |
| 124 | 124 | | |
| 125 | 125 | ; ============================================================================ | |
| 126 | 126 | ; MEMORY MAP | |
| ... | |||
| 163 | 163 | CIA1_PRA = $DC00 | |
| 164 | 164 | CIA1_PRB = $DC01 | |
| 165 | 165 | | |
| 166 | - | ; Track positions | |
| 167 | - | TRACK1_ROW = 8 | |
| 168 | - | TRACK2_ROW = 12 | |
| 169 | - | TRACK3_ROW = 16 | |
| 166 | + | ; Track positions (balanced spacing) | |
| 167 | + | TRACK1_ROW = 8 ; High track | |
| 168 | + | TRACK2_ROW = 12 ; Mid track | |
| 169 | + | TRACK3_ROW = 16 ; Low track | |
| 170 | 170 | | |
| 171 | 171 | ; HUD positions | |
| 172 | - | HEALTH_ROW = 23 | |
| 173 | - | PROGRESS_ROW = 24 | |
| 172 | + | HEALTH_ROW = 23 ; Health bar row | |
| 173 | + | PROGRESS_ROW = 24 ; Progress bar row | |
| 174 | 174 | | |
| 175 | 175 | ; Combo display position | |
| 176 | - | COMBO_ROW = 2 | |
| 176 | + | COMBO_ROW = 2 ; Combo display row | |
| 177 | 177 | | |
| 178 | 178 | ; Hit zone | |
| 179 | - | HIT_ZONE_COLUMN = 3 | |
| 179 | + | HIT_ZONE_COLUMN = 3 ; Where notes are hit | |
| 180 | 180 | | |
| 181 | 181 | ; Custom character codes | |
| 182 | 182 | CHAR_NOTE = 128 | |
| ... | |||
| 187 | 187 | CHAR_BAR_EMPTY = 132 | |
| 188 | 188 | | |
| 189 | 189 | ; Note settings | |
| 190 | - | MAX_NOTES = 8 | |
| 191 | - | NOTE_SPAWN_COL = 37 | |
| 190 | + | MAX_NOTES = 8 ; Maximum simultaneous notes | |
| 191 | + | NOTE_SPAWN_COL = 37 ; Where notes appear | |
| 192 | 192 | | |
| 193 | 193 | ; Timing | |
| 194 | - | FRAMES_PER_BEAT = 25 | |
| 195 | - | END_DELAY_FRAMES = 75 | |
| 194 | + | FRAMES_PER_BEAT = 25 ; 50fps / 25 = 2 beats per second = 120 BPM | |
| 195 | + | END_DELAY_FRAMES = 75 ; 1.5 seconds after song ends | |
| 196 | 196 | | |
| 197 | 197 | ; Zero page | |
| 198 | 198 | ZP_PTR = $FB | |
| ... | |||
| 948 | 948 | jmp draw_press_key | |
| 949 | 949 | draw_press_key_done: | |
| 950 | 950 | | |
| 951 | - | lda #5 | |
| 951 | + | lda #5 ; Green border for success | |
| 952 | 952 | sta BORDER | |
| 953 | 953 | | |
| 954 | 954 | rts | |
| ... | |||
| 1267 | 1267 | ora #$30 | |
| 1268 | 1268 | sta SCREEN + (14 * 40) + 25 | |
| 1269 | 1269 | | |
| 1270 | - | lda #$25 | |
| 1270 | + | lda #$25 ; % symbol | |
| 1271 | 1271 | sta SCREEN + (14 * 40) + 26 | |
| 1272 | 1272 | | |
| 1273 | 1273 | lda #5 | |
| ... | |||
| 1328 | 1328 | ; ---------------------------------------------------------------------------- | |
| 1329 | 1329 | | |
| 1330 | 1330 | define_custom_chars: | |
| 1331 | + | ; Note character - arrow/chevron shape | |
| 1331 | 1332 | lda #%00000110 | |
| 1332 | 1333 | sta CHARSET + (CHAR_NOTE * 8) + 0 | |
| 1333 | 1334 | lda #%00011110 | |
| ... | |||
| 1345 | 1346 | lda #%00000110 | |
| 1346 | 1347 | sta CHARSET + (CHAR_NOTE * 8) + 7 | |
| 1347 | 1348 | | |
| 1349 | + | ; Track line character | |
| 1348 | 1350 | lda #%00000000 | |
| 1349 | 1351 | sta CHARSET + (CHAR_TRACK * 8) + 0 | |
| 1350 | 1352 | sta CHARSET + (CHAR_TRACK * 8) + 1 | |
| ... | |||
| 1357 | 1359 | sta CHARSET + (CHAR_TRACK * 8) + 6 | |
| 1358 | 1360 | sta CHARSET + (CHAR_TRACK * 8) + 7 | |
| 1359 | 1361 | | |
| 1362 | + | ; Hit zone character | |
| 1360 | 1363 | lda #%01100110 | |
| 1361 | 1364 | sta CHARSET + (CHAR_HITZONE * 8) + 0 | |
| 1362 | 1365 | sta CHARSET + (CHAR_HITZONE * 8) + 1 | |
| ... | |||
| 1367 | 1370 | sta CHARSET + (CHAR_HITZONE * 8) + 6 | |
| 1368 | 1371 | sta CHARSET + (CHAR_HITZONE * 8) + 7 | |
| 1369 | 1372 | | |
| 1373 | + | ; Full bar character | |
| 1370 | 1374 | lda #%11111111 | |
| 1371 | 1375 | sta CHARSET + (CHAR_BAR_FULL * 8) + 0 | |
| 1372 | 1376 | sta CHARSET + (CHAR_BAR_FULL * 8) + 1 | |
| ... | |||
| 1377 | 1381 | sta CHARSET + (CHAR_BAR_FULL * 8) + 6 | |
| 1378 | 1382 | sta CHARSET + (CHAR_BAR_FULL * 8) + 7 | |
| 1379 | 1383 | | |
| 1384 | + | ; Empty bar character | |
| 1380 | 1385 | lda #%11111111 | |
| 1381 | 1386 | sta CHARSET + (CHAR_BAR_EMPTY * 8) + 0 | |
| 1382 | 1387 | lda #%10000001 | |
| ... | |||
| 1697 | 1702 | jmp game_over_press | |
| 1698 | 1703 | | |
| 1699 | 1704 | game_over_done: | |
| 1700 | - | lda #2 ; Red border | |
| 1705 | + | lda #2 ; Red border for failure | |
| 1701 | 1706 | sta BORDER | |
| 1702 | 1707 | rts | |
| 1703 | 1708 | | |
| ... | |||
| 1870 | 1875 | ; POLISHED SOUND EFFECTS | |
| 1871 | 1876 | ; ============================================================================ | |
| 1872 | 1877 | | |
| 1873 | - | ; ---------------------------------------------------------------------------- | |
| 1874 | 1878 | ; Play Perfect Hit Sound - Bright, high, satisfying | |
| 1875 | - | ; ---------------------------------------------------------------------------- | |
| 1876 | - | | |
| 1877 | 1879 | play_perfect_sound: | |
| 1878 | 1880 | lda #0 | |
| 1879 | 1881 | sta SID_V3_FREQ_LO | |
| ... | |||
| 1890 | 1892 | sta SID_V3_CTRL | |
| 1891 | 1893 | rts | |
| 1892 | 1894 | | |
| 1893 | - | ; ---------------------------------------------------------------------------- | |
| 1894 | 1895 | ; Play Good Hit Sound - Positive but lesser | |
| 1895 | - | ; ---------------------------------------------------------------------------- | |
| 1896 | - | | |
| 1897 | 1896 | play_good_sound: | |
| 1898 | 1897 | lda #0 | |
| 1899 | 1898 | sta SID_V3_FREQ_LO | |
| ... | |||
| 1910 | 1909 | sta SID_V3_CTRL | |
| 1911 | 1910 | rts | |
| 1912 | 1911 | | |
| 1913 | - | ; ---------------------------------------------------------------------------- | |
| 1914 | 1912 | ; Play Miss Sound - Harsh buzz | |
| 1915 | - | ; ---------------------------------------------------------------------------- | |
| 1916 | - | | |
| 1917 | 1913 | play_miss_sound: | |
| 1918 | 1914 | lda #0 | |
| 1919 | 1915 | sta SID_V3_FREQ_LO | |
| ... | |||
| 2263 | 2259 | bne draw_progress_label | |
| 2264 | 2260 | draw_progress_label_done: | |
| 2265 | 2261 | | |
| 2266 | - | lda #$1A | |
| 2262 | + | lda #$1A ; Z label | |
| 2267 | 2263 | sta SCREEN + (TRACK1_ROW * 40) | |
| 2268 | 2264 | lda #TRACK1_NOTE_COL | |
| 2269 | 2265 | sta COLRAM + (TRACK1_ROW * 40) | |
| 2270 | 2266 | | |
| 2271 | - | lda #$18 | |
| 2267 | + | lda #$18 ; X label | |
| 2272 | 2268 | sta SCREEN + (TRACK2_ROW * 40) | |
| 2273 | 2269 | lda #TRACK2_NOTE_COL | |
| 2274 | 2270 | sta COLRAM + (TRACK2_ROW * 40) | |
| 2275 | 2271 | | |
| 2276 | - | lda #$03 | |
| 2272 | + | lda #$03 ; C label | |
| 2277 | 2273 | sta SCREEN + (TRACK3_ROW * 40) | |
| 2278 | 2274 | lda #TRACK3_NOTE_COL | |
| 2279 | 2275 | sta COLRAM + (TRACK3_ROW * 40) | |
| ... | |||
| 2832 | 2828 | rts | |
| 2833 | 2829 | | |
| 2834 | 2830 | ; ============================================================================ | |
| 2835 | - | ; SONG DATA | |
| 2831 | + | ; SONG DATA - First Song (Balanced for Phase 1) | |
| 2832 | + | ; ============================================================================ | |
| 2833 | + | ; Format: beat, track (1-3), SID frequency high byte | |
| 2834 | + | ; Note spacing provides learnable pattern with variety | |
| 2836 | 2835 | ; ============================================================================ | |
| 2837 | 2836 | | |
| 2838 | 2837 | song_data: | |
| 2839 | - | !byte 0, 1, $47 | |
| 2840 | - | !byte 2, 2, $2C | |
| 2841 | - | !byte 4, 3, $11 | |
| 2838 | + | ; Opening - gentle introduction | |
| 2839 | + | !byte 0, 1, $47 ; Beat 0: Track 1, high note | |
| 2840 | + | !byte 2, 2, $2C ; Beat 2: Track 2, mid note | |
| 2841 | + | !byte 4, 3, $11 ; Beat 4: Track 3, low note | |
| 2842 | 2842 | | |
| 2843 | + | ; Build - add more notes | |
| 2843 | 2844 | !byte 8, 1, $3B | |
| 2844 | 2845 | !byte 10, 2, $27 | |
| 2845 | 2846 | !byte 12, 3, $13 | |
| 2846 | 2847 | | |
| 2848 | + | ; Complexity - overlapping patterns | |
| 2847 | 2849 | !byte 16, 1, $35 | |
| 2848 | 2850 | !byte 17, 2, $2C | |
| 2849 | 2851 | !byte 18, 1, $3B | |
| 2850 | 2852 | !byte 20, 3, $16 | |
| 2851 | 2853 | | |
| 2854 | + | ; Theme repeats | |
| 2852 | 2855 | !byte 24, 1, $47 | |
| 2853 | 2856 | !byte 26, 2, $35 | |
| 2854 | 2857 | !byte 28, 3, $11 | |
| 2855 | 2858 | | |
| 2859 | + | ; Variation | |
| 2856 | 2860 | !byte 32, 2, $2F | |
| 2857 | 2861 | !byte 34, 1, $4F | |
| 2858 | 2862 | !byte 36, 3, $17 | |
| 2859 | 2863 | | |
| 2864 | + | ; Building intensity | |
| 2860 | 2865 | !byte 40, 1, $58 | |
| 2861 | 2866 | !byte 42, 2, $2C | |
| 2862 | 2867 | !byte 44, 3, $11 | |
| 2863 | 2868 | !byte 46, 2, $27 | |
| 2864 | 2869 | | |
| 2870 | + | ; Climax section | |
| 2865 | 2871 | !byte 48, 1, $6A | |
| 2866 | 2872 | !byte 49, 2, $35 | |
| 2867 | 2873 | !byte 50, 1, $58 | |
| 2868 | 2874 | !byte 52, 3, $1A | |
| 2869 | 2875 | !byte 54, 2, $2F | |
| 2870 | 2876 | | |
| 2877 | + | ; Resolution | |
| 2871 | 2878 | !byte 56, 1, $47 | |
| 2872 | 2879 | !byte 58, 2, $2C | |
| 2873 | 2880 | !byte 60, 3, $11 | |
| 2874 | 2881 | !byte 62, 1, $35 | |
| 2875 | 2882 | | |
| 2876 | - | !byte $FF | |
| 2883 | + | !byte $FF ; End marker | |
| 2877 | 2884 | | |
| 2878 | 2885 | ; ---------------------------------------------------------------------------- | |
| 2879 | 2886 | ; Note Arrays | |
| ... | |||
| 2900 | 2907 | health: !byte 0 | |
| 2901 | 2908 | combo: !byte 0 | |
| 2902 | 2909 | max_combo: !byte 0 | |
| 2910 | + | | |
| 2911 | + | ; ============================================================================ | |
| 2912 | + | ; END OF SID SYMPHONY - PHASE 1 COMPLETE | |
| 2913 | + | ; ============================================================================ | |
| 2903 | 2914 | |