Apr 1, 2024

The hearts of the Super Nintendo

When I start studying a vintage system, the first thing I like to do is understand how its components work together at the hardware level [1] .

Every computer has at least one heart which dictates the tempo to all the other chips. The C lo CK output pin is connected to a copper line which spreads to most components, into their CLK input pin.

If you are mostly a software person like me, you may have never noticed it but all kinds of processors have a CLK input pin. From CPUs (Motorola 68000 [2] , Intel Pentium [3] , MOS 6502 [4] ), to custom graphic chips (Midway's DMA2 [5] , Capcom CPS-A [6] /CPS-B [7] , Sega's Genesis VDP [8] ) to audio chips (Yamaha 2151 [9] , OKI msm6295 [10] ), they all have one.

How is the CLK generated?

The CLK can be generated by two types of components. One is a crystal oscillator which usually looks like a flattened capsule. The others are named ceramic resonators .…