Air Combo Guide (still testing)

Preface:

Code can be added to the end of the ROM. Then you can use commands like 4E B9 (jsr) or 4E F9 (jmp) to go there.
Alternatively, you can go to the address 1F4BC0, where there are thousands of "FF"s. They are neither data nor code. They are placeholders to make the size of the ROM a multiple of 1MB. If you want to save the size of your ROM, you can modify these "FF"s and place your code there instead of adding your code to the end of the ROM.

STEP I (Air Combo) *************************************************************

Go to the end of the ROM, add
0C 6A 00 06 00 0C 62 06 08 AA 00 07 00 49 4E 75
And remember the beginning address of your code, for example XX YY ZZ

Then go to 54B8, change those 6 bytes to
4E B9 00 XX YY ZZ (the address of your code)

STEP II (Invulnerability when lying on the ground) *****************************

Go to the end of the ROM again, add
4A 6A 00 5E 
6A 06 
4E F9 00 00 E9 B6 
08 AA 00 07 00 49 
4E F9 00 00 E9 C2
And remember the beginning address of your code, for example UU VV WW.

STEP III (Enemy gets hit) ******************************************************

Go to E964, and change E964~E9C1 to
4E B8 54 1A 
4A 2A 00 4A 
67 06 
53 2A 00 4A 
4E 75 
08 2A 00 02 00 48 
66 00 00 C4 
08 2A 00 03 00 48 
66 00 01 14 
30 2A 00 92 
08 2A 00 00 00 0F 
67 06 
91 6A 00 40 
60 04 
D1 6A 00 40 
20 2A 00 2E 
D1 AA 00 5E 
06 AA 00 00 40 00 00 2E 
6B 06 
4E F9 00 UU VV WW (the address above)
08 2A 00 07 00 48 
67 B4 
4E F8 51 3A

Effect: If the enemies are hit in the air, as long as they haven't touched the ground, the player should be able to continue attacking.
Player characters will not be affected.

STEP IV (Enemy gets thrown) *****************************************************

If you do not change this part, a thrown enemy will hit nearby enemies one time every frame, and cause incredibly damage.
So let's do this. Go to the end of the ROM, and add

B7 CA 
67 0E 
0C 6B 00 0A 00 00 
67 06 
4E F9 00 00 51 48 
4E F9 00 00 52 10

And remember the beginning address of your code, for example QQ PP OO

Then go to 5142, change the 6 bytes to
4E F9 00 QQ PP OO (the address above)

STEP V (Player mustn't grab an enemy in the air) *******************************

Go to the end of the ROM, and add
B7 CA 
67 0E 
0C 6B 00 0A 00 00 
67 06 
4E F9 00 00 52 c2 
4E F9 00 00 53 48

And remember the beginning address of your code, for example HH MM NN

Then go to 52BC, change the 6 bytes to
4E F9 00 HH MM NN (the address above)

The following characters have unique code for their action when they are thrown, so we must modify the code for each of them:

Rocketman:

Go to the end of the ROM, and add
4E B8 54 1A 4A 2A 00 4A 67 06 4E F9 00 01 A0 CC 4E F9 00 01 A0 D2
And remember the beginning address of your code, for example ZZ YY XX
Then go to 1A0C6, change the 6 bytes to
4E F9 00 ZZ YY XX

Zamza

Go to the end of the ROM, and add
4E B8 54 1A 4A 2A 00 4A 67 06 4E F9 00 01 7C 50 4E F9 00 01 7C 56
And remember the beginning address of your code, for example VV WW UU
Then go to 17C4A, change the 6 bytes to
4E F9 00 VV WW UU

Go to the end of the ROM, and add
4A AA 00 5E 6A 06 4E F9 00 01 7C 98 08 AA 00 07 00 49 4E F9 00 01 7C A8
And remember the beginning address of your code, for example QQ PP XX
Then go to 17C92, change the 6 bytes to
4E F9 00 QQ PP XX

Robot

Go to the end of the ROM, and add
4E B8 54 1A 4A 2A 00 4A 67 06 4E F9 00 01 DD C2 4E F9 00 01 DD C8
And remember the beginning address of your code, for example ZZ MM NN
Then go to 1DDBC, change the 6 bytes to
4E F9 00 ZZ MM NN

Go to the end of the ROM, and add
4A 6A 00 5E 6A 06 4E F9 00 01 DE 0A 08 AA 00 07 00 49 4E F9 00 01 DE 1A
And remember the beginning address of your code, for example VV YY ZZ
Then go to 1DE04, change the 6 bytes to
4E F9 00 VV YY ZZ

Shiva

Go to the end of the ROM, and add
4E B8 54 1A 4A 2A 00 4A 67 06 4E F9 00 01 FF 42 4E F9 00 01 FF 48
And remember the beginning address of your code, for example XX VV WW
Then go to 1FF3C, change the 6 bytes to
4E F9 00 XX VV WW

Go to the end of the ROM, and add
4A AA 00 5E 6A 06 4E F9 00 01 FF 8A 08 AA 00 07 00 49 4E F9 00 01 FF 9A
And remember the beginning address of your code, for example QQ PP YY
Then go to 1FF84, change the 6 bytes to
4E F9 00 QQ PP YY

After the above steps, the game system shall look like early Mortal Kombat and Street Fighter Alpha 3.

OPTIONAL (gravity) *************************************************************

You may change the gravity to make the enemies fly slower, so that you can hit them more times.

Here are the addresses of the gravity:
Normal enemies: E9AA
Rocketman: 1A114
Zamza: 17C8C
Robot: 1DDFE
Shiva: 1FF7E

To modify the enemy flying speed, go to 54C8, you will see
35 7C 00 02 00 92
Change 02 to the value you want.

Tutorial by Dha Lau Hoo (Da Lao Hu)