Motorola MC4044P - The Commodore 64 clock generator

The Motorola MC4044P is chip that contains building blocks to construct a phase locked loop (PLL). This is technology from the 1970s, later technology such as the 74HC4046, did provide all PLL components on a single chip, and in the modern 21th century world, we have fully featured clock chips. However, back in the day, engineers had to build an entire clock circuit from parts and the MC4044P provides building blocks to build a PLL, the core of a clock circuit.

Early Commodore 64 mainboards have such a disintegrated clock circuit, which consists of a crystal oscillator, voltage controlled oscillator, the MC4044P, and clock dividers. While the MC4044P is still offered in various places, it can be challenging to find it at the right price for repairs or new builds.

On offer here are new-old-stock MC4044Ps with 1997 date code. I bought these from an American IC trader, packaged in original Motorola tubes, therefore I believe these chips have never been used before, they are really new.

The MC4044P should not be confused with the CD4044, which is an entirely different chip. Later Commodore 64 mainboards use a custom clock chip, the MOS8701. The MC4044P and MOS8701 are incompatible and cannot be swapped with each other.