[Coco] Timer interrupt frequency (50Hz vs 60 Hz)

[RETRO Innovations]

On 3/20/2025 7:07 PM, Alex Evans via Coco wrote:
> Yes, you can interrupt (IRQ) on hsync on any coco.

So if you write:

prep:

//put 0 in NUM

// put 0 in START

//enable fsync

// wait for START to equal 2

// use NUM value to calc PAL or NTSC


fsync_IRQ

// increment START

// if START = 1

// zero out NUM, enable hsync, and return

// else disable fsync and hsync and return

hsync_IRQ:

// increment NUM

// return

Would the above give you different numbers in NUM you could use to
determine PAL/NTSC?

Jim

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