Editing MOD (file format) (section)

== Timing ==
In the original MOD file the minimum time frame was 0.02 seconds, or a "[[Analog television#Vertical_synchronization|vertical blanking]]" (VSync) interval, because the original software used the VSync timing of the monitor running at 50&nbsp;Hz (for [[PAL]]) or 60&nbsp;Hz (for [[NTSC]]) for timing.

The rate at which pattern data is played is defined by a ''speed setting''. Each row in the pattern data lasts one vertical blanking (or 0.02 seconds) times the current speed setting. The speed setting varied from 1 to 255.
In later versions of the format, the vertical blanking was replaced with an adjustable time period staying in the range [0.01, 0.078] seconds. The old speed setting command was replaced with a new one that was used to change both the old speed setting and the new adjustable time period. Unfortunately, some of the old functionality was broken, because the new speed setting command had an identical code value to the old command. Values in the range [1, 31] were interpreted as the old speed settings, but other values were regarded as modifications to the adjustable time period. Hence, values in the range [32, 255] used in some old songs broke in new versions of the player.

Further information on the MOD format can be found at the alt.binaries.sounds.mods FAQ.<ref>{{cite web|url=http://cd.textfiles.com/darkdomain/faqs/faq-mod_v28-part1.txt |title=The alt.binaries.sounds.mods FAQ on the MOD format |access-date=2020-04-15}}</ref>