VJ runs at 60 FPS in NTSC mode, 30 in PAL mode

[ericde45]

when running virtualjaguar --ntsc, fps are 60
running virtualjaguar --pal give 30 fps
even when running virtualjaguar without any program/rom

[djipi]

Thank you to have report this issue. It is also present in the original VJ (checked with vj-20160613-win64, and 2.1.2).

[djipi]

Investigation provided additional clues.

• The fps reports slightly more than 60 fps in NTSC
  -- This is due to the timer in charge of the main loop, value should be 16.6 but timer needs an integer, so 16 is used as value.
• The test in PAL shows main loop takes a significant amount of time in each loop
  -- Ticks calculus should use a value of 20 but, got a values range between 0x1a to 0x24 instead.