Retro Games THEC64 User Manual page 107

set to 50 Hz, as will an C64 NTSC computer when the output is set to 60 Hz. This is
their native mode.
Computer
C64 PAL
C64 NTSC
C64 PAL
C64 NTSC
The pre-installed C64 games available in Carousel mode run on a mixture of NTSC
and PAL C64 and VIC 20 computers without you having to change anything. The type
of computer that launches a program from the Media access function or from BASIC in
Classic mode also varies based on a number of different settings, but again they are
either running on a PAL or an NTSC computer model.
What this means is that some programs will run faster and some will run slower
depending upon the current video output setting and the type of computer model in
use.
For some programs, the increase or decrease in speed only makes a superficial
difference. For others, the difference is a little more obvious, especially in regards to
the pitch of the audio on the running program.
To compensate, THEC64 applies some automatic adjustments to make the pitch of the
audio as close to the original experience as possible when a program is not running
in its native mode. This is called Audio Scaling.
AUDIO SCALING
By default, THEC64 automatically applies an audio scaling algorithm when a program
is running. This dynamically calculates the required audio shift based on the current
Video output mode, the running program, the computer model in use (NTSC or PAL)
and the speed of the original computer model.
This option attempts to make the audio shift sound correct even when the program is
running at an increased or decreased speed.
Video output
50 Hz
50 Hz
60 Hz
60 Hz
97
Speed
About right
Slower
Faster
About right