I know the vdp cmd engine is faster where the screen is off.

Does anyone know if the vdp engine is faster WHEN it's processing a command during VBLANK instead ?

So if i send a command that takes 1 sec to be done (such as a lmmm for an entire page in screen 7), during execution
there are 50 or 60 cycles of screen rebuild.
My guess is : during execution there are some intervals of time (VBLANK) where the VDP is faster and other where VDP il slower? (screen build up). (1)

If (1) is true can i get more speed with the tecnique shown below?

at vblank turn the screen 0ff; set also a HBLANK at scanline 16.
AT HBLANK set the screen on. Doing this i should cut down the first 16 lines but i gain some speed. It's true?

The command engine runs faster whenever there is nothing to display: forced blanking (display disable) but also VBLANK. Running with 192 lines instead of 212 will give you better command engine performance. And using less than 192 lines per frame by enabling/disabling display on line interrupts (that is what you mean, right?) should speed things up even more.

Quote:

The command engine runs faster whenever there is nothing to display: forced blanking (display disable) but also VBLANK. Running with 192 lines instead of 212 will give you better command engine performance. And using less than 192 lines per frame by enabling/disabling display on line interrupts (that is what you mean, right?) should speed things up even more.

thx, mth is what i mean...

PD: Just DISABLING SPRITES vdp's cmd is a lot fasters!!!.