FPA-PAL-S01 pinout

FPA-PAL-S01 and FPA-92-S01: 22-pin 0.4" PDIP (Four Score and Famicom Four-Player Adapter)

Present in NES FOUR SCORE, both PAL and NTSC; and in HORI 4 PLAYERS ADAPTOR

           .---v---.
 P2 CLK <- |01   22| -- +5V
 P2 D0  -> |02   21| <- /4P (LOW) or 2P (HIGH)
 P3 CLK <- |03   20| -> P1 CLK
 P3 D0  -> |04   19| <- P1 D0
 P4 CLK <- |05   18| -> P1,P2,P3,P4 STROBE (BUFFERED)
 P4 D0  -> |06   17| <- STROBE
TURBO B -> |07   16| -> $4016 D0
TURBO A -> |08   15| <- $4016 CLK
  XTAL1 -> |09   14| -> $4017 D0
  XTAL2 <- |10   13| <- $4017 CLK
    GND -- |11   12| <- SIGNATURE SELECT (*)
           `-------`

PIN 12 | $4016 reads 16-24  | $4017 reads 16-24
 GND   |       $10          |        $20
 +5V   |       $20          |        $10

Source: [1]