User Tools

Site Tools


base:efficient_tod_initialisation

Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revisionPrevious revision
Next revisionBoth sides next revision
base:efficient_tod_initialisation [2019-05-12 20:34] silverdrbase:efficient_tod_initialisation [2019-05-17 12:58] – [Dual purpose] silverdr
Line 62: Line 62:
     ; we run on PAL machine with 60Hz TOD clock     ; we run on PAL machine with 60Hz TOD clock
 </code> </code>
-we can determine not only the TOD frequency but also the video standard. This is possible because – unlike the TOD frequency – the CPU clock frequency is directly related to the computer's video standard. PAL computers have their CPU (and CIAs) clocked at 985248.444Hz while NTSC ones run faster and have their CPU/CIAs clocked at 1022727.14Hz. This is a side-effect of deriving all (except TOD) required clock frequencies from a single crystal of either 14318180Hz (for NTSC machines) or 17734472Hz (for PAL ones).+we can determine not only the TOD frequency but also the video norm. This is possible because – unlike TOD frequency – the CPU clock frequency is directly related to the computer's video standard. PAL computers have their CPU (and CIAs) clocked at 985248.444Hz while NTSC ones run faster and have their CPU/CIAs clocked at 1022727.14Hz. This is a side-effect of deriving all (except TOD) required clock frequencies from a single crystal of either 14318180Hz (for NTSC machines) or 17734472Hz (for PAL ones).
base/efficient_tod_initialisation.txt · Last modified: 2020-10-27 02:31 by silverdr