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Understand the Atari 2600's 6532 RIOT timer and ports, including interval selection, one-shot timing, underflow state, and scanline-safe diagnostics.
Model POKEY channel pairing, AUDF/AUDC dividers, polynomial sources, timer IRQs, and AUDCTL changes as observable clocked hardware.
Reproduce the HuC6280's seven-bit interval timer, oscillator prescaler, reload edge, interrupt request flag, and counter-read caveat in PC Engine software.
Interpret BIOS INT 1Ah system ticks and rollover state without consuming the midnight notification that DOS needs to advance its date.
Chain an INT 1Ch handler without stealing BIOS timer work, keep interrupt-time code bounded, and remove a TSR hook without corrupting the vector chain.
Model the Game Boy's hidden divider, falling-edge timer input, DIV/TAC write effects, delayed TIMA reload, and model-specific validation boundaries.