Charge shot

References

1. ^ abMega Man 2's Mega Buster has no charge. It fires only on the frame B goes down, with a free shot slot.Codelsmmega/mm2
   How we know

   20@mega_buster:
   21	LDA z:zjoy1_pressed_bits
   22	AND #b_button
   23	BEQ @skip_2
   24	LDX #$04
   ⋮
   26@loop_1:
   27	LDA aobject_flag, X
   28	BPL @not_exist_1
   29	DEX
   30	CPX #$01
   

   Checked against the evidence by its author, an AI model, 2026-10-21.

   Checked by a second AI model, 2026-10-21.

   In the claim ledger

2. ^ abA B press fires a normal shot and sets the charge counter to 1; each frame B stays held in a state below 4 the counter rises by 1, looping from 100 back to 92. On release, a counter under 32 ($20) fires nothing more, 32 or more fires a half-charged shot, and 92 ($5C) or more a full one.Codeplasticsmoke/megaman4-disassembly-ca65 · “Mega Man 4 (USA) (Rev 1)”
   How we know

   73L_8073:
   74    LDA $35                             ; charge counter
   75    BEQ L_80CF                          ; not charging: done
   76    LDA player_state                    ; player state
   77    CMP #$04                            ; states >= 4 (Rush riding etc.)
   78    BCS L_80CF                          ; cannot charge: done
   79    LDA joy1_held                       ; held buttons
   80    AND #$40                            ; B button still held?
   81    BEQ L_80CF                          ; released: fire handled at L_8CCC
   82    INC $35                             ; advance charge
   83    LDA $35                             ; reload charge
   ⋮
   89    LDA $35                             ; reload charge
   ⋮
   

   1694    LDA $35                             ; charge counter
   1695    BEQ L_8D2F                          ; no charge: check B press
   1696    LDA current_weapon                  ; current weapon
   1697    BNE L_8D2F                          ; not buster: check B press
   1698    LDA joy1_held                       ; held buttons
   1699    AND #$40                            ; B still held?
   1700    BNE L_8D59                          ; still charging: no fire
   1701    LDA #$21                            ; charged spawn offset $21
   1702    STA $11                             ; set spawn-offset index
   ⋮
   1705    LDA $35                             ; charge counter
   ⋮
   1707    LDA #$00                            ; zero
   ⋮
   1710    CMP #$20                            ; level 1 threshold ($20)
   ⋮
   

   1743L_8D2F:
   1744    LDA joy1_press                      ; newly pressed
   1745    AND #$40                            ; B button?
   1746    BEQ L_8D5B                          ; no fire: done
   1747L_8D35:
   1748    LDY #$00                            ; slot 0 marker
   1749    STY temp_00                         ; clear chosen-slot temp
   1750    INY                                 ; Y = 1
   1751    STY $35                             ; minimum charge (tap)
   

   1769L_8D59:
   1770    LDA #$00                            ; A = 0 (no shot fired)
   1771L_8D5B:
   1772    RTS                                 ; done
   

   In the cartridge (“Mega Man 4 (USA) (Rev 1)”): bank $3C $8073, the counter in the Rev 1 ROM; bank $3C $8CF2, the thresholds in the Rev 1 ROM. We don't reproduce the bytes.

   Checked against the evidence by its author, an AI model, 2026-10-21.

   Checked by a second AI model, 2026-10-21.

   In the claim ledger

3. ^ abMega Man 5 moves Mega Man 4's charge thresholds. On release its counter $38 fires a normal shot from 16 ($10), a half-charged one from 40 ($28), and a full one from 80 ($50), and nothing under 16; Mega Man 4's counter, which starts at 1 on the press, fires nothing under 32, a half charge from 32, and a full one from 92. So the full charge needs a lower count and the half charge a higher one.Codeplasticsmoke/megaman5-disassembly-ca65 · plasticsmoke/megaman4-disassembly-ca65revised
   How we know

   buster_charge_ctl: lda $32 bne L910F lda $30 cmp #$04 beq L910F lda $16 and #$40 bne buster_charge_tick lda $38 cmp #$10 bcc L910F cmp #$50 …

   buster_charge_tick: lda $38 cmp #$20 bne L9148 … L9148: inc $38

   buster_tier_threshold:.byte $28,$50,$FF

   buster_tier_preset:.byte $18,$A8,$A9

   1751    STY $35                             ; minimum charge (tap)
   

   1710    CMP #$20                            ; level 1 threshold ($20)
   1711    BCC L_8D59                          ; tap shot: normal spawn
   1712    INC $36                             ; flash phase 8
   1713    CMP #$40                            ; level 2 threshold ($40)
   1714    BCC L_8D0C                          ; small charge
   1715    INC $36                             ; flash phase 9
   1716    CMP #$5C                            ; full charge threshold ($5C)
   

   Checked against the evidence by its author, an AI model, 2026-10-21.

   Revised after a check by a second AI model, 2026-10-21.

   In the claim ledger

4. ^In the US 1.1 version of Star Fox 64, holding A counts a charge counter up by 1 a player update to a cap of 21, and an update without A held counts it down by 1 (Player_UpdateLockOn). A fresh press of A, whose own update first adds 1 to the counter, fires the charged shot (PLAYERSHOT_LOCK_ON) if an enemy is locked on or the counter is then above 10 (so 10 or more before the press). Either path fires only if the player's charged-shot slot (gPlayerShots[14 - player->num]) is free, holds a shot of another type, or holds a charged shot that has lost its target (the locked path) or grown past scale 1 (the counter path); a press that fires nothing sets the counter to 0. Once the counter is above 20, while A is held, nothing is locked, and Z and R aren't both held, it launches a search shot every fourth game frame, and the first targetable enemy within 300 units of that shot on each axis (200 in all-range mode) is locked on for a count of 20, which counts down only while A is up. Each update while its target stays locked, the charged shot turns toward it (PlayerShot_UpdateLockOnShot).Codesonicdcer/sf64revised
   How we know

   3186bool Player_UpdateLockOn(Player* player) {
   ⋮
   3190    if (gInputHold->button & A_BUTTON) {
   3191        gChargeTimers[player->num]++;
   3192        if (gChargeTimers[player->num] > 21) {
   3193            gChargeTimers[player->num] = 21;
   ⋮
   3201            ((gGameFrameCount % 4) == 0) && Player_CanLockOn(player->num)) {
   3202            if (gChargeTimers[player->num] > 20) {
   ⋮
   3206                            Player_SetupArwingShot(player, &gPlayerShots[i], 0.0f, 0.0f, PLAYERSHOT_LOCK_SEARCH,
   ⋮
   3217        if (gChargeTimers[player->num] != 0) {
   3218            gChargeTimers[player->num]--;
   

   3164bool Player_CanLockOn(s32 playerNum) {
   ⋮
   3169        if ((actor->obj.status == OBJ_ACTIVE) && (actor->lockOnTimers[playerNum] != 0)) {
   3170            return false;
   

   3222    if (gInputPress->button & A_BUTTON) {
   3223        for (i = 0; i < ARRAY_COUNT(gActors); i++) {
   3224            if ((gActors[i].obj.status == OBJ_ACTIVE) && (gActors[i].lockOnTimers[player->num] != 0)) {
   3225                if ((gPlayerShots[14 - player->num].obj.status == SHOT_FREE) ||
   3226                    (gPlayerShots[14 - player->num].obj.id != PLAYERSHOT_LOCK_ON) ||
   3227                    ((gPlayerShots[14 - player->num].obj.id == PLAYERSHOT_LOCK_ON) &&
   3228                     (gPlayerShots[14 - player->num].unk_60 != 0))) {
   ⋮
   3230                        Player_SetupArwingShot(player, &gPlayerShots[14 - player->num], 0.0f, 0.0f, PLAYERSHOT_LOCK_ON,
   ⋮
   3239                break;
   ⋮
   3243        if (gChargeTimers[player->num] > 10) {
   3244            if ((gPlayerShots[14 - player->num].obj.status == SHOT_FREE) ||
   3245                (gPlayerShots[14 - player->num].obj.id != PLAYERSHOT_LOCK_ON) ||
   ⋮
   

   69            gControllerPress[i].button =
   70                (gControllerHold[i].button ^ sPrevController[i].button) & gControllerHold[i].button;
   

   1758    if (gLevelMode == LEVELMODE_ON_RAILS) {
   1759        lockRange = 300.0f;
   1760    } else {
   1761        lockRange = 200.0f;
   ⋮
   1765        if ((actor->obj.status == OBJ_ACTIVE) && (actor->info.targetOffset != 0.0f) &&
   1766            ((actor->lockOnTimers[shot->sourceId] == 0) && (fabsf(shot->obj.pos.x - actor->obj.pos.x) <= lockRange) &&
   1767             (fabsf(shot->obj.pos.y - (actor->obj.pos.y + actor->info.targetOffset)) <= lockRange) &&
   1768             (fabsf(shot->obj.pos.z - actor->obj.pos.z) <= lockRange))) {
   1769            actor->lockOnTimers[shot->sourceId] = 20;
   

   2848    } else if (this->lockOnTimers[TEAM_ID_FOX] != 0) {
   2849        if (!(gControllerHold[gMainController].button & A_BUTTON)) {
   2850            this->lockOnTimers[TEAM_ID_FOX]--;
   ⋮
   2852        gChargeTimers[0] = 0;
   

   2174        if (shot->unk_60 == 0) {
   ⋮
   2177                    (actor->lockOnTimers[shot->sourceId] != 0)) {
   2178                    var_a3 = 1;
   2179                    actor->lockOnTimers[shot->sourceId] = 2;
   2180                    sLockOnPos = actor->obj.pos;
   ⋮
   2188                    var_a3 = 1;
   ⋮
   2193                    } else {
   ⋮
   2200            if (var_a3 != 0) {
   ⋮
   2218                Math_SmoothStepToAngle(&shot->vec_2C.y, sp58, 1.0f, shot->unk_50, 0.0f);
   2219                Math_SmoothStepToAngle(&shot->vec_2C.x, sp5C, 1.0f, shot->unk_50, 0.0f);
   ⋮
   2221            } else {
   2222                shot->unk_60 = 1;
   

   Checked against the evidence by its author, an AI model, 2026-10-22.

   Revised after a check by a second AI model, 2026-10-22.

   In the claim ledger