Retroarch player 3 & 4 won't work

[ALIE]

I have set the confiqs just like 1 and 2. Using psx core medafin and the yellow text appear saying controller us turned on and detected. But the games only sees 2?

[SentaiBrad]

The PS1 only had two controller ports and very little games supported 4 players (Similar to the NES). So it's either a setting missing around the Multi-Tap or I would guess to say it's just less than functional. Did you check the Core Settings for multi-tap settings or controller configs for something that says multi-tap or anything like that?