data/claims/simons-quest.yamlCastlevania II - Simon's Quest (USA), read in the ROM
Simon's Quest replaces Castlevania's step table with a speed and gravity; a jump from the ground takes off at 4 px/frame up, every airborne frame adds 0.21875 px/frame² of gravity, and a fall is capped at 3 px/frame, where Castlevania steps a fixed 20-entry table and falls past its end at 8 px/frame. simons-quest/jump-line
About: Castlevania II: Simon's Quest Jump
Value
{
"speed": 4,
"gravity": 0.21875,
"maxFall": 3
}0xC8E9-0xC93A — bank 3 $88D9-$892A, the take-off: Y speed $036C.$037E = −4.0 ($FC.$00), the action set to jumping, and the held d-pad read into the X speed and facingCastlevania II - Simon's Quest (USA) · 0xC9E6-0xCA1D — bank 3 $89D6-$8A0D, each jumping frame: zero the speed on a ceiling, add $38 to the speed's fraction ($DFE4), and cap a fall at 3.0Castlevania II - Simon's Quest (USA) · 0x1DFF4-0x1E009 — bank 7 $DFE4-$DFF9, a 16-bit add of $0008 to object X's Y speedCastlevania (USA) (Rev 1) · 0x19B9D-0x19BB4 — Castlevania's jump table, 20 signed steps between a $80 and a $81 marker (castlevania/jump-table)Castlevania (USA) (Rev 1) · 0x19B53-0x19B6E — Castlevania's fall past the table's end, 8 px per frame (castlevania/table-end-fall)Checked by claude, 2026-10-21 — disassembled each range in the pinned ROMs; FoxCunning's Castlevania2 disassembly (SimonExecuteCurrentAction2_Jumping_5_Falling, Object_GravityAccelerateBy_Var08) led to themBy these numbers the rise peaks near 36 px, Castlevania's height, but that hasn't been measured. On a moving platform (object types $21, $22, $34, $3D) the take-off adds the platform's speed to −3.875 instead.
Cited by: Castlevania, Castlevania II: Simon's Quest, Gravity, Jump
In Simon's Quest the take-off sets Simon's horizontal speed to 1 px/frame toward a held Left or Right, or 0, and the jumping state reads only B, for the whip, so the jump keeps its direction as in Castlevania. simons-quest/air-direction
About: Castlevania II: Simon's Quest Air control
Value: 1 px/frame
CodeCastlevania II - Simon's Quest (USA) ·0xC8E9-0xC93A — bank 3 $8905-$8928: held Right ($F7 bit 0) sets X speed $6D.$6C = 1.0, Left −1.0 and facing left, neither 0Castlevania II - Simon's Quest (USA) · 0xC9DD-0xCA1D — bank 3 $89CD-$8A0D, the jumping state: a new B press ($F5 AND $40) goes to the whip; the rest is the vertical speedCastlevania (USA) (Rev 1) · 0x19411-0x1944B — Castlevania's take-off copying the held Left and Right into Simon's direction (castlevania/jump-start)Checked by claude, 2026-10-21 — disassembled the ranges in the pinned ROMsNot measured in the game.
Cited by: Air control, Castlevania II: Simon's Quest, Variable jump height
Simon's Quest turns an enemy's touch into a launch, not Castlevania's table arc; as in Castlevania, Simon is turned to face the enemy and moved away from it, here at 2.5 px/frame up and 1 px/frame back, held in a hurt state for 32 frames that runs the jump's speed and gravity code before he falls normally. simons-quest/knockback
About: Castlevania II: Simon's Quest Knockback
Value
{
"up": 2.5,
"back": 1,
"frames": 32
}0x4854-0x4864 — bank 1 $8844-$8854, after the hit's damage: facing $0420 = 1 if the enemy's X is at or right of Simon's, else 0; then jump to $D36FCastlevania II - Simon's Quest (USA) · 0x1D37F-0x1D3B7 — bank 7 $D36F-$D3A7: X speed −1.0 if $0420 is nonzero, else +1.0; Y speed −2.5 ($FD.$80); action 6; a 32-frame counter $04B0 = $20Castlevania II - Simon's Quest (USA) · 0xCA1E-0xCA31 — bank 3 $8A0E-$8A21, action 6: count down $04B0, running the jumping physics at $89D6, then action 2Castlevania (USA) (Rev 1) · 0x196E1-0x1972C — Castlevania's hit, which points Simon's arc at a second table (castlevania-line/knockback)Checked by claude, 2026-10-21 — disassembled each range in the pinned ROMs; FoxCunning's disassembly labels the routine SimonDamageKnockBack and action 6 TakingDamageThrown$0420 = 1 is facing right: the take-off (bank 3 $8905-$8923, in jump-line's first range) stores 1 there with a held Right and its +1.0 speed, and 0 with Left. FoxCunning's label for it, ObjectFacingLeft, is reversed. So an enemy on the right turns Simon right and pushes him left.
Cited by: Castlevania, Castlevania II: Simon's Quest, Knockback
Simon's Quest keeps a clock of days, hours, and minutes in BCD that advances one minute every 15 frames outside the stopped cases, and when the hour reaches 6 or 18 it starts the day-night transition; a day is 24 hours. simons-quest/clock
About: Castlevania II: Simon's Quest Time of day
Value
{
"framesPerMinute": 15,
"framesPerHour": 900,
"dawn": 6,
"dusk": 18,
"hoursPerDay": 24
}0x1D777-0x1D7D9 — bank 7 $D767-$D7C9: no tick in map type 5, in Simon's action $0B, while $34 is set, or while $8F stops time; else a counter $84 to 15, then minute $85 + 1 to 60, hour $86 + 1 to 24 (then day $83 + 1, up to 99); hour 6 or 18 jumps to the transitionCastlevania II - Simon's Quest (USA) · 0x1CEE8-0x1CEED — bank 7 $CED8-$CEDD, in the transition, IsNightTime $82 flipped with XOR 1Checked by claude, 2026-10-21 — disassembled both ranges in the pinned ROM; FoxCunning's disassembly names the routine AccumulateClockTime and the variables (CurrentMinuteBCD, CurrentHourBCD, IsNightTime)A half day, 12 hours, is 10,800 frames, about three minutes at the NES's 60.1 frames a second.
Cited by: Castlevania II: Simon's Quest, Time of day
In Simon's Quest an enemy placed while it's night starts with double the hit points its level data gives, except a few object types and in the mansions. simons-quest/night-hp
About: Castlevania II: Simon's Quest Time of day
Value: 2 ×
CodeCastlevania II - Simon's Quest (USA) ·0x411D-0x415C — bank 1 $810D-$814C: if IsNightTime ($82), and the type isn't $21, $22, $25-$27, $2D-$2F, or $34, and map type ($30) isn't 1, the HP byte is shifted left once before it's stored in $04C2Castlevania 2 - Bloodlust: a full disassembly and hack of Castlevania II: Simon's Quest · bank_2.asm#L531 — the level-data labels, which file map type 1 under the mansionsLevelData_Stairs_1_Mansions_2_3_11_12:Checked by claude, 2026-10-21 — disassembled the range in the pinned ROM; read the label at the pinned commitThe excluded types haven't been identified.
Cited by: Castlevania II: Simon's Quest, Time of day
In Simon's Quest hearts are both subweapon ammunition and money; the knives' routine and a merchant's deal both call one routine that subtracts a BCD price from the heart count and refuses when there aren't enough, and the knives' routine passes it 1 heart, or 2 for one of them. simons-quest/hearts
About: Castlevania II: Simon's Quest Weapon energy
Value
{
"knife": 1,
"otherKnife": 2
}0x1D866-0x1D8A1 — bank 7 $D856-$D891: the subweapon wrapper ($D856) and the check ($D867), a BCD subtraction from hearts $48/$49 that stores the result only if it doesn't go below 0Castlevania II - Simon's Quest (USA) · 0x1D8E6-0x1D8F4 — bank 7 $D8D6-$D8E4, the knives: cost 2 for subweapon 3, else 1, through $D856Castlevania II - Simon's Quest (USA) · 0x1EDA0-0x1EDA9 — bank 7 $ED90-$ED99, a merchant deal calling the same $D867 with its priceChecked by claude, 2026-10-21 — disassembled the ranges in the pinned ROM; FoxCunning's disassembly labels CheckEnoughHearts_SubtractIfOk and the merchant codeFoxCunning's labels name subweapons 2 and 3 the knives; its listing of the other subweapons' handlers differs from the ROM, so they aren't stated here.
Cited by: Castlevania II: Simon's Quest, Weapon energy
Simon's Quest sells whips; a paid merchant deal whose index is $18 or above sets the whip level outright from the item, where Castlevania raises it one level per whip that a bonus drops. simons-quest/whip-bought
About: Castlevania II: Simon's Quest Whip upgrade
CodeCastlevania II - Simon's Quest (USA) ·0x1EDAE-0x1EDB3 — bank 7 $ED9E-$EDA3, after the hearts are paid, item $18 and up branch to $EDEDCastlevania II - Simon's Quest (USA) · 0x1EDFD-0x1EE0D — bank 7 $EDED-$EDFD: whip level $0434 = (item AND $1F) − 7Castlevania (USA) (Rev 1) · 0x1EBD3-0x1EBFE — Castlevania's drop rule (castlevania-line/whip-drop)Checked by claude, 2026-10-21 — disassembled the ranges in the pinned ROMsFoxCunning's comments list the deal indices 24, 27, and 30 as the thorn whip, chain whip, and morning star. The atlas hasn't searched the ROM for other writes to $0434.
Cited by: Castlevania II: Simon's Quest, Whip upgrade