Partially MOS Technology CIA (Complex Interface Adapter) 6526. But CIA is also an I/O chip. https://en.wikipedia.org/wiki/MOS_Technology_CIA#Interval_timers ht

Partially MOS Technology CIA (Complex Interface Adapter) 6526. But CIA is also an I/O chip. https://en.wikipedia.org/wiki/MOS_Technology_CIA#Interval_timers https://en.wikipedia.org/wiki/MOS_Technology_CIA#Interval_ti... Same for these two, they contain not only timers, but also other peripherals: MOS Technology 6532 RIOT (RAM-I/O-Timer): https://en.wikipedia.org/wiki/MOS_Technology_6532 https://en.wikipedia.org/wiki/MOS_Technology_6532 MOS Technology 6522 VIA (Versatile Interface Adapter): https://en.wikipedia.org/wiki/MOS_Technology_6522 https://en.wikipedia.org/wiki/MOS_Technology_6522 There are more similar variants of MOS I/O chips as well.