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Old 22 December 2012, 19:28   #4
Toni Wilen
WinUAE developer
Join Date: Aug 2001
Location: Hämeenlinna/Finland
Age: 43
Posts: 20,635
Originally Posted by mark_k View Post
It wouldn't make vblank-synced programs run at half speed, since the vertical blank interrupt is generated by the custom chips independent of the fact that the HSYNC and VSYNC pins on Agnus are used as inputs when a genlock is connected.
Says who? That can't be correct, at least without more proof

Sync signals are either generated by Agnus or by genlock, not both and everything is synced to genlock when genlock is active. Whole system hangs if genlock mode is enabled without sync signals coming from genlock.

ROM graphics.library routine also checks genlock by enabling genlock mode and then checking if vertical line (VPOS) counter stops. (Which is source for vblank strobe which Paula sees and generates vblank interrupt)
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