The period table used by S3M is smaller than the one used by the MOD format (only 12 entries, compared to between 36 and 60 for the MOD variations) and uses larger values in order to be able to compute the extra-fine pitch slides.
The key formula for this takes into account the instrument's stored sample rate at middle C. One feature of the S3M format which is seldom used, is the format's support for FM instruments.
These were designed to be played back on sound cards that included an OPL2 or compatible FM synthesis chip.
More recently, with the necessary CPU power available, it is possible to perform the same synthesis in software.
[3] S3M files released on the Demoscene's music scene in the 1990s were commonly played on PCs using dedicated mod/s3m players (such as DMP) or using the tracker software (like Scream Tracker).