[PS2onPS4] [HELP] How are these 4-player patches done?

[Nicoful]

Hi. Do anyone have any idea Kozarovv found these offsets for the 4-player patches (see the mtap related code in the spoilers below)?

The PS2 emulator can't handle inputs for games that require multitap to be connected on port 2, these are seen as controller 2A, 2B, 2C, 2D and are therefore not read.
Kozarovv solves this by finding offsets for these inputs and redirects them back to multitap 1 in this order:
2A -> 1B,
2B -> 1C,
2C -> 1D.

I would love to know what tools being used and if there is certain function calls to look for in memory by using cheat engine or similar.
If you have any ideas how this could be done I'm all ears since I have a favourite game on my own that have the same problem (Sega ages 2500: Decathlete Collection [SLPM-62444]).

Example #1:
Def Jam™ Fight for N.Y.® NTSC (4 Player fix)

Spoiler

Comment:

4 player working. All thanks to Kozarovv for his multi-tap patches. Tested quite a bit, works great.

-- Def Jam: Fight for NY (SLUS-21004)
-- Multi-Tap fix by Kozarovv
-- ported to PS4 by Stayhye
-- emu used=aofa

CLI

--mtap1=always​

--mtap2=always​

LUA

apiRequest(0.1)​

​

local eeObj = getEEObject()​

​

local mtap_fix = function()​

-- Force controllers detection​

eeObj.WriteMem32(0x32F3EC,0x00000000)​

-- Manually count to 8...​

eeObj.WriteMem32(0x1EADFC,0x24100000)​

eeObj.WriteMem32(0x1EAE04,0x26100001)​

-- Rearrange controllers from port 2 to 1​

eeObj.WriteMem32(0x0fff00,0x10040007)​

eeObj.WriteMem32(0x0fff04,0x28b90003)​

eeObj.WriteMem32(0x0fff08,0x54190001)​

eeObj.WriteMem32(0x0fff0c,0x24a50001)​

eeObj.WriteMem32(0x0fff10,0x54190001)​

eeObj.WriteMem32(0x0fff14,0x24040000)​

eeObj.WriteMem32(0x0fff18,0x080CBBD0)​

eeObj.WriteMem32(0x0fff1c,0x00000000)​

eeObj.WriteMem32(0x0fff20,0x54050001)​

eeObj.WriteMem32(0x0fff24,0x24040001)​

eeObj.WriteMem32(0x0fff28,0x54050001)​

eeObj.WriteMem32(0x0fff2c,0x24a5ffff)​

eeObj.WriteMem32(0x0fff30,0x080CBBD0)​

eeObj.WriteMem32(0x0fff34,0x00000000)​

eeObj.WriteMem32(0x32F36C,0x0c03ffc0)​

end​

​

emuObj.AddVsyncHook(mtap_fix)​

Example #2:
Urban Reign™ NTSC NTSC (4 Player Fix) +Cheats)

Spoiler

Comment:

Big thanks to Kozarovv for this one! Finally 4 player multi-tap works! Apparently the emulator is flawed in how it handles multi-tap when it involves "--mtap2". All functions for 2A, 2B, 2C, 2D must be redirected to ports on multi-tap 1.

-- Urban Reign NTSC (SLUS-21209)
-- Multitap fix by Kozarovv
-- ported to PS4 by Stayhye
-- emu used=kof98um

CLI

--mtap1=Always​

LUA

apiRequest(0.1)​

​

local gpr = require("ee-gpr-alias")​

​

local emuObj = getEmuObject()​

local eeObj = getEEObject()​

local gsObj = getGsObject()​

​

​

emuObj.PadSetLightBar(0, 45,65,55)​

emuObj.SetDeinterlace(true)​

emuObj.SetDisplayAspectWide()​

​

​

local WS = function()​

-- Init first mtap​

eeObj.WriteMem32(0x12BA88,0x24040000)​

-- Read data from 1B port when 2A is requested​

eeObj.WriteMem32(0x0ffc00,0x10040005)​

eeObj.WriteMem32(0x0ffc04,0x00000000)​

eeObj.WriteMem32(0x0ffc08,0x14050003)​

eeObj.WriteMem32(0x0ffc10,0x24040000)​

eeObj.WriteMem32(0x0ffc14,0x24050001)​

eeObj.WriteMem32(0x0ffc18,0x080c5cbd)​

eeObj.WriteMem32(0x0ffc1c,0x24030070)​

eeObj.WriteMem32(0x3172ec,0x0803ff00)​

​

emuObj.ThrottleMax()​

end​

​

emuObj.AddVsyncHook(WS)​

​

emuObj.SetGsTitleFix( "globalSet", "reserved", { workLoadThreshold = 100000} )​

emuObj.SetGsTitleFix( "globalSet", "reserved", { waveThreshold = 90000} )​

emuObj.SetGsTitleFix( "ignoreAreaUpdate", 0, { } )​