Unbricked doesn't use the VBlank interrupt

[quinnyo]

Using the VBlank interrupt is the correct way to manage frame timing and the main loop.

[quinnyo]

Some notes on my thoughts on ideas of a solution:

I think this should be its own lesson, covering:

• the VBlank period for safe to access OAM, VRAM (this gets introduced earlier, so here would be tying those threads)
• the problem with using a busy loop to wait (power usage and wasting cpu time)
• interrupts as a concept, interrupt requests/vectors/handlers
  • preserving the CPU registers & the stack?

The "point"/framing of the lesson would be cleaning up the main loop / graphics code?
// the graphics code part is kind of dependent on OAM DMA though, which isn't strictly related to the VBlank interrupt... (?)

[Peter1169]

I'd like to work on this. My plan is to add a focused Part II lesson that introduces the VBlank interrupt, replace the current rLY polling frame loop with a VBlank interrupt flag + halt loop in Unbricked, and keep the later example code in sync. I'll open a PR once I can build the example ROMs.