'Retrace (V-Sync) Playback Rate' Switch: r[song[,song]...]

The purpose of this switch is to set the playback method(s) to be used for the song(s) in a PSID file to Retrace-replay.

The switch can optionally be followed by a list of comma-separated song numbers (ranging from 1 to the elsewhere specified max. number of songs) If the -r switch is not followed by one or more tune numbers, the playback method of all tunes in the file is set to Retrace-replay. If this switch is given in combination with the -R switch (Timer), that (the Timer-switch) is the one processed first (e.g. -r2 -R would set all tunes but tune 2 (which will use v-sync) to timer replay).

Two methods are available: V-Sync ("Dislay Vertical Retrace") and Timer:

V-Sync is dependent on whether you have a European PAL-system version of the Commodore 64, or whether you have a version for the American NTSC-system. On PAL systems, the play routine will be called 50 times a second (i.e. 50Hz), whereas the polling frequency on NTSC systems is 60Hz. (Yes, this is why raster-bars/effects from those American demos looks god-awful over here - and vice versa! .-)

Timer replay can be used to poll the player at a fixed frequency, regardless of which C64 version you have (also, the timer is sometimes used for digital replay of samples). The rate defaults to 60Hz, but if you program the timer in the init routine, the rate you set here will be used. Timer replay was rarely a method used in original C64 productions, because using the timer to replay will cause periodic interruptions possible seriously messing up critical raster timing (some - particular older - players take even more than 32 lines of rastertime!); hence, V-Sync replay is the most normal thing used in C64 music, in order to be able to decide for oneself "where" on the screen the time is to be consumed. For SID Play, however, raster timing is of no concern, so if you want to make sure the music is always played at the same speed, you may consider using Timer replay. (But be perfectly sure you set the correct timer frequency, almost all European music is designed for 50 Hz!!!)

Example: psidTool.EXE Alien.C64 *.SID -a -i$1000 -p$1003 -title:"Alien" -author:"Mads Orbesen Troest (Hobbit)" -copy:"1992 Artificial Arts, LASER Inc" -r
Example: psidTool.EXE Whoppers.C64 *.SID /a /i$1000 /p$1003 /title:"Whoppers - The Soundtrack" /author:"Mads Orbesen Troest (Hobbit)" /copy:"1991 Artificial Arts, LASER Inc" /R1 -r2,3


This page was last modified at 15:03:37 CET on 1999-12-12 (AutoStamped)