!!! Rockman technical data
!! Introduction
This is technical data that has been analyzed from the Rockman game ROM for the purpose of making Rockman tool-assisted speedruns as precise as possible.
The [http://bisqwit.iki.fi/jutut/megamansource/|disassembly] of the game has been an invaluable help in discovering these.
All numbers on this page are ''hexadecimal'' unless otherwise mentioned.
%%TOC%%
!! Coordinate system
In Rockman and Rockman 2, every object of the game has the following properties:
- Screen number (00―FF), it tells which screen the object resides in.
- X position (00.00―FF.FF), it tells where in the screen the object is in.
- Y position (00.00―FF.FF), it tells where in the screen the object is in.
- X speed (−80.00―7F.FF).
- Y speed (−80.00―7F.FF).
The position of the object has 8 bits of decimal part, but only the integer part can be observed on the screen.
- Y coordinates increase towards the bottom of the screen
- X coordinates increase towards the right
- Negative Y speed means falling, positive Y speed means ascending
- X speed is always positive. It is subtracted or added depending on Rockman’s facing.
!! Vertical motion
! Jump curve
- In Rockman 1 and 2, when Rockman jumps, his Y speed is set to 04.DF.
- In Rockman 3, when Rockman jumps, his Y speed is set to 04.A5.
- In Rockman 4, when Rockman jumps, his Y speed is set to 04.C0.
- Every frame, 00.40 is subtracted from his Y speed (0.25 in decimal).
- In Rockman 1 and 2, if the Y speed grows smaller than −0C.00 (−12 in decimal), it is set to −0C.00.
- In Rockman 3 and 4, if the Y speed grows smaller than −07.00, it is set to −07.00.
- In Rockman 1 and 2, if the Y speed is larger than 02.1F and the player is not holding the A button, the speed is immediately set to 01.00.
- In Rockman 3 if [[rules unknown and] the player is not holding the A button, the speed is immediately set to −00.80.
- In Rockman 4 if [[rules unknown and] the player is not holding the A button, the speed is immediately set to −00.00.
! Walking on lifts / magnet beam
During walking on a magnet beam or a lift, Rockman’s Y speed grows continuously as if he was falling. However the lift/beam forces his Y position (actually, only the integer part of it) to be stable.
This effect happens in Rockman, but not in Rockman 2.
- In Rockman 2, Item 1 forces Rockman’s Y speed to be 01.00.
- In Rockman 3, RC makes Rockman’s Y speed first 06.AE, then the rest is decided by gravity.
! Walking on solid ground
Every frame when Rockman bumps into an platform either from top or below (magnet beams and lifts don’t count), Rockman’s Y speed is set into a constant.
- Rockman 1: −00.C0.
- Rockman 2: −00.40.
Top collision checked only when moving upwards, bottom collision checked only when moving downwards.
If he has an obstacle below him, his Y position is adjusted accordingly.
! Magical Y coordinates
- Y coordinate F8 (−08) means a dead object.
- When Rockman jumps, the game prevents the coordinate from decreasing below −04 (FC). (Only true in Rockman 1.) ** However it is possible to land on a beam that forces the coordinate to be −05. This is the highest possible coordinate where Rockman can be.
- To zip through ceiling at screen top, Y speed must be −08.C0 or faster. (Smaller speed leads to death on attempt to zip.)
- To survive the spikes in Bombman stage when performing [Finalfighter]’s {{r1bombsuper.mpg}} trick, Y speed must be −01.C0 or faster before scrolling.
! Climbing
- In Rockman 1 and 2, Rockman climbs at speed of 00.C0.
- In Rockman 3, Rockman climbs at speed of 01.4C.
! Transforming
- In Rockman 1, Rockman’s Y speed and position are accumulated even during transforming. (Which allows him to pass through enemies without hurting himself.)
- In Rockman 2, Y speed is reset when pausing. During transforming, enemies move. (Which allows them to pass through Rockman without hurting him.)
- In Rockman 3, transformation is an extension to pause. Game continues after transformation from the same situation that was before pause.
- Since Rockman 4, Rockman no longer transforms after pause/weapon switch.
!! Horizontal motion
! Jumping
- In Rockman 1 and 2, during jumping/falling into some direction, Rockman’s X speed is 01.50.
- In Rockman 3 and 4, during jumping/falling, Rockman’s X speed is the same as when walking.
- If the player stops pressing the directional button, the speed falls immediately into 00.00.
- In Rockman 1, if Rockman starts moving after not moving, his X speed first goes to 00.20, then back to 01.50.
- In Rockman 2, if Rockman starts moving after not moving, his X speed goes immediately back to 01.50.
! Walking
Walking speed
- In Rockman 1 and 2, during walking, Rockman’s X speed is 01.60.
- In Rockman 3 and 4, during walking, Rockman’s X speed is 01.4C.
Sliding speed
- In Rockman 3 and 4, during sliding, Rockman’s X speed is 02.80.
Acceleration
- In Rockman 1, when Rockman accelerates from non-full speed (full halt or deacceleration), his X speed is 00.20 for 9 frames before gaining full speed.
- In Rockman 2, when Rockman accelerates from non-full speed (full halt or deacceleration, item-throwing halt excluded), his X speed is 00.20 for 7 frames before gaining full speed.
- In Rockman 3, when Rockman accelerates from non-full speed, he walks normally the first frame (as far as speed is concerned), then is completely in stall for 8 frames, after which he has the full speed again.
Deceleration
- In Rockman 1, when Rockman decelerates from full speed (not from acceleration), his X speed is 00.80 for 13 (decimal) frames before halting completely.
- In Rockman 2, when Rockman decelerates from full speed (not from acceleration), his X speed is 00.80 for 8 (decimal) frames before halting completely.
- In Rockman 3, when Rockman decelerates from full speed (not from acceleration), he moves normally for 1 frame, after which he halts immediately (though the sprite indicates deceleration for 8 frames).
!! Magnet beams (Rockman 1)
There may be at maximum 5 magnet beams simultaneously active.
Every magnet beam has the following properties:
- Screen number where the ''center'' of the beam is anchored in
- X position within that screen (00―FF)
- Y position within that screen (00―FF)
- Length (00―41)
- Life (00―9C)
- Cycle position (00―10)
! Lifecycle
Beams die when
- Their Life is 00
- A boss battle starts
- A stage is loaded (death for example)
Beams don’t die when
- Screen scrolls
When a new magnet beam is created:
- Length=1
- Cycle=0
- Life=9C
As long as B button is held:
- Life does not decrease
- Length increases by 1 every frame, unless it is already 41
- Beam center position is readjusted, see below
- If the beam far end is inside a wall, the beam is released (as if B button was no longer held)
When B button is no longer held:
- Life decreases by 1 every frame, unless it is already 00
- If Life is 0, the beam is forgotten
Every frame when the beam exists:
- Cycle position is increased by 1
- If (Cycle_position×8) == (Length×2), Cycle position is reset to 0
! Beam center position
Note: All numbers in this section are decimal, not hexadecimal.
As long as the player holds B, the beam center is adjusted according to Rockman’s position.
- Beam Y position is set to Rockman’s Y position
- A temporary variable is calculated: ** Temp = (Beam_length_before_growth × 2 + 16) ** If(Temp & 7)==0, then Temp = Temp+8
- If Rockman looks to the right, then Beam X position = Rockman’s X position + Temp
- If Rockman looks to the left, then Beam X position = Rockman’s X position − Temp
For lengths 1-65, the X position of the beam is therefore adjusted in the following ways:
1:+24[[1]M>32 17:+56[[5]M>96 33:+88[[9]M>160 49:+120[[13]M>224 65:+152[[17]M>288
2:+18[[1]>26 18:+50[[5]>90 34:+82[[9]>154 50:+114[[13]>218 65:+146[[17]>282
3:+20[[1]>28 19:+52[[5]>92 35:+84[[9]>156 51:+116[[13]>220
4:+22[[2]m>38 20:+54[[6]m>102 36:+86[[10]m>166 52:+118[[14]m>230
5:+24[[2]>40 21:+56[[6]>104 37:+88[[10]>168 53:+120[[14]>232
6:+26[[2]>42 22:+58[[6]>106 38:+90[[10]>170 54:+122[[14]>234
7:+28[[2]>44 23:+60[[6]>108 39:+92[[10]>172 55:+124[[14]>236
''''
8:+30[[3]m>54 24:+62[[7]m>118 40:+94[[11]m>182 56:+126[[15]m>246
9:+40[[3]M>64 25:+72[[7]M>128 41:+104[[11]M>192 57:+136[[15]M>256
10:+34[[3]>58 26:+66[[7]>122 42:+98[[11]>186 58:+130[[15]>250
11:+36[[3]>60 27:+68[[7]>124 43:+100[[11]>188 59:+132[[15]>252
12:+38[[4]m>70 28:+70[[8]m>134 44:+102[[12]m>198 60:+134[[16]m>262
13:+40[[4]>72 29:+72[[8]>136 45:+104[[12]>200 61:+136[[16]>264
14:+42[[4]>74 30:+74[[8]>138 46:+106[[12]>202 62:+138[[16]>266
15:+44[[4]>76 31:+76[[8]>140 47:+108[[12]>204 63:+140[[16]>268
16:+46[[5]m>86 32:+78[[9]m>150 48:+110[[13]m>214 64:+142[[17]m>278
Note: The second “65” is when the beam no longer grows. The number in [[brackets]] is the beam length in units.
-
Add 1 and multiply by 16 to get the carrying width of the beam. ** 32 at minimum, 272 at maximum. ** The game actually uses half of this value (range for each side from the center of the beam), so it does not overflow even when ≥ 256.
-
m = nearest distance of beam for each length (important when operating on next screen (different than displayed))
-
M = biggest distance of beam (often the optimal choice for zipping)
-
number = location of the far end of the beam
!! Randomness
See the main article: [RandomGenerators|randomness generators].
!! Memory addresses
Read from the [http://bisqwit.iki.fi/jutut/megamansource/|disassembly].
|| Game || Screen# || X (hi,lo) || Xspd (hi,lo) || Y (hi,lo) || Yspd (hi,lo) | Rockman 1 | $460 | $480:$4A0 | $4C0:$4E0 | $600:$620 | $660:$680 | Rockman 2 | $440 | $460:$480 | $600:$620 | $4A0:$4C0 | $640:$660 | Rockman 3 | $380 | $360:$340 | no RAM address? | $3C0:$3A0 | $460:$440 | Rockman 4 | $348 | $330:$318 | no RAM address? | $378:$360 | $3F0:$3D8 | Rockman 5 | | | | | | Rockman 6 | | | | | The variables for object #{{n}} can be found by adding {{n}} to each address.%%% Boss has {{n}}=1 in RM1/2, Rockman always has {{n}}=0.
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- [GameResources/NES/Rockman|Rockman Tricks]