Clock rate: Difference between revisions

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=== NTSC/PAL differences ===
#REDIRECT [[Cycle reference chart]]
Consoles in the USA and Europe run at different speeds due to the different television standards used. The main differences between the NTSC and PAL PPUs is as follows:
{| border=1
! Property || NTSC || PAL
|-
| Master clock speed || 21.477272MHz<br>= 236.25 MHz / 11 || 26.601712MHz
|-
| PPU clock speed || 21.477272MHz / 4 || 26.601712MHz / 5
|-
| Corresponding CPU clock speed || 1/3 PPU clock speed || 1/3.2 PPU clock speed
|-
| Height of picture || 240 scanlines || 240 scanlines
|-
| Nominal visible picture height<br>(see [[Overscan]]) || 224 scanlines || 268 scanlines
|-
| Length of VBLANK || 20 scanlines || 70 scanlines
|-
| Timing quirks || First scanline is one PPU cycle shorter during every other frame || None
|}
Other than these differences (and video output), the NTSC and PAL PPUs function exactly the same.

Latest revision as of 05:39, 20 November 2018