[GeraldSommariva]

Is the Encoder IC and PMOS device its supplied with +5v and -12V ?

I found this on PMOS Logic From Wikipedia:-

Most PMOS integrated circuits require a power supply of 17-24 volt DC.[20] The Intel 4004 PMOS microprocessor, however, uses PMOS logic with polysilicon rather than metal gates allowing a smaller voltage differential. For compatibility with TTL signals, the 4004 uses positive supply voltage VSS=+5V and negative supply voltage VDD = -10V.[21]