That's likely intended to be a Kempston Joystick interface.
5 - A4 (this is wrong! Should be A5)
20 - !IORQ
21 - !RD
D66 - 555LL1/LS32
D68 - 555IR22/LS373
Pin3/Pin2 -> D0 -> Right
Pin13/Pin12 -> D1 -> Left
Pin07/Pin06 -> D2 -> Down
Pin14/Pin15 -> D3 -> Up
Pin18/Pin19 -> D4 -> Fire
Standard (western) connector is DSUB-9 male "Atari Joystick" (switching joystick buttons to ground), most russian ZX clones used DIN5 or DIN8 (switching buttons to VCC/5V) to my knowledge
Pinout can be seen here:
https://k1.spdns.de/Vintage/Sinclair...schematics.gif[свернуть]