User:Evie (Torchickens)/Sandbox

Evie's list of things she wants to do, or has recently come across but doesn't know much about. Feel free to add details if you like.

Timing

• Cycles
• DMA transfer: ~160 microseconds
• ~FF46 write - began OAM DMA transfer (one byte RAM specified for h (high byte) in RAM pointer that mirrors rDMA/FEXX-9F (you know this))
• "LY indicates the current horizontal line, which might be about to be drawn, being drawn, or just been drawn. LY can hold any value from 0 to 153, with values from 144 to 153 indicating the VBlank period."
• You can only access HRAM while a DMA transfer is taking place.
• "the rDIV register, which itself is incremented at a rate of 16384Hz (~16779Hz on SGB)"
• From that RNG correlation article "516 cycles (2.015625 rDIV periods)" - so just say 2/516 (1/258 rDIV) for one cycle.
• OAM corruption bug
• Video Display/VBlank
• Microsecond counter
• It's more complex than this, but just leave these notes for now.

To-do: Defaults and relationship with Game Boy, GBC, SGB boot ROMs.

Hexadecimal byte representation of Cryo's real-time RAM writer for writing code using button sequences

https://archives.glitchcity.info/forums/board-115/thread-7744/page-0.html

Red/Blue EN:

2EFE1D5414D523CD
FA3F3DF0F8FE0CC8
F0B237B728F143B9
4228EB4F41865077
4418E4

Catch rate correspondence table (Generation I)

Red/Blue

ID Pokemon Catch rate Held item in Gen 2
00 'M (00) 1D Carbos
01 Rhydon 3C Silver Leaf

Exceptions:

Changes to catch rate in games (Thx Bulbapedia):

• In Yellow, starter Pikachu hold Light Ball
• In Yellow, wild Kadabra hold TwistedSpoon
• In Yellow, wild Dragonair hold Protein
• In Yellow, wild Dragonite hold Antidote
• Stadium gift Pokémon hold Normal Box (Round 1) or Gorgeous Box (Round 2)

Converted catch rates (TimeCapsule_CatchRateItems):

• Catch rate 0x19 becomes Leftovers
• 0x2D becomes Bitter Berry
• 0x32 becomes Gold Berry
• 0x5A, 0x64, 0x78, 0x87, 0xBE, 0xC3, 0xDC, 0xFA, 0xFF all become Berry

How to acquire a Pokémon with any catch rate:

(Tested on Yellow probably works the same on Red/Blue)

• Have in party only special MissingNo. (Kabutops Fossi, Aerodactyl, Ghost), then save/reset
• Manipulate D0C0-1 (W_MONHCATCHRATE). (Probably can do this with LWA)
• Encounter/acquire special MissingNo. (Kabutops Fossi, Aerodactyl, Ghost) and catch it
• The acquired Pokémon will have the catch rate from D0C0-1.

IR trade pet project

Theory

Use $FF56 to turn infrared on in two games with arbitrary code execution. Synchronise the PPU(?) cycles. Use a modified version of the Cable Club code.

In it, have a prompt to keep the Game Boy Colors next to each other for each interaction (press A to start read/write) and have some kind of error prevention if communication fails.

I wonder how practical this is because for Gold/Silver they used IR for different purposes (obtaining decorations, items, Trainer House Trainers).

Other things

(Archived as the page gets big)