DKC Atlas Forum

[gizaha]

Hello there.
On dkc2 ips patch:
A9 59 86 LDA #$8659 ;Lower 16 bits of blank SPC track address
85 32 STA $32 ;Store to scratch RAM
A9 F5 00 LDA #$00F5 ;Upper 16 bits/bank of blank SPC track address
85 34 STA $34 ;Store to scratch RAM

Why we use 8659 and 00F5?
What is scratch RAM?

[Mattrizzle]

Cross-posting this from elsewhere.

Why we use 8659 and 00F5?

8659 and 00F5 combine to form the SNES HiROM pointer $F5:8659 (PC address 358659, which points to a custom-made blank music track. There is normally blank space at this address in an unedited ROM. Here is the structure of the block:

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ROM $F5:8659:     00 13 16 00 //upload 0x16 times two (0x2C) bytes to $1300 in SPC700 RAM

SPC700 RAM $1300: 1E 13 2B 13 2B 13 2B 13 2B 13 2B 13 2B 13 2B 13
//pointer to each channel in music tracks 01-06

SPC700 RAM $1310: 80 FF
//If I recall correctly, these bytes are the base tempo of the music and sound effects, respectively.

SPC700 RAM $1312: 00 13 00 13 00 13 00 13 00 13 00 13
//Pointer to channel pointer table for each music track. In this case, they all point to $1300.

SPC700 RAM $131E: 15 37 23 23 18 7F 0A 01 01 01 01 01 01
//Music data; channel 00. There isn't anything audible here--command 15 sets the echo for sound effects, while command 18 sets the FIR filter.

SPC700 RAM $132B: 00
//Music data; channels 01-07. 00 = end of music data, so these also play nothing.

What is scratch RAM?

Scratch RAM is general-purpose RAM. For DKC2, one block of scratch RAM is located between $32 and $4A. It can have different uses depending on the code currently being executed. For example, the subroutine responsible for loading the music data stores the address of the data block to be loaded at addresses $32-$34 in RAM.

[gizaha]

Thank you very much, especially for the spc700 analysis.

[gizaha]

Cross-posting this from elsewhere.

Code: Select all

SPC700 RAM $1310: 80 FF
//If I recall correctly, these bytes are the base tempo of the music and sound effects, respectively.


You can't imagine how you helped me with this. Zeroing the tempo of the song leads to mute spc track. It's the safest fastest way
and i guess it's compatible with all games.
I sit all day in the home today and i think i already completed the ips patch FROM SCRATCH for killer instinct.