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StingRay · 18 November 2014, 06:34

Exactly.

This piece of code is needed for interrupts to work properly on 68010+ machines as these can have a relocated vector base, simply changing $6c.w to install a custom VBI for example won't work anymore if VBR is set to any other location than $0, $6c+VBR offset must be used in that case. And this is exactly what happens in these lines of code (a0: VBR):

Code:

	lea	.NewVBI(pc),a1
	move.l	a1,$6c(a0)

18 November 2014, 06:34	#10
StingRay move.l #$c0ff33,throat Join Date: Dec 2005 Location: Berlin/Joymoney Posts: 6,863	Exactly. This piece of code is needed for interrupts to work properly on 68010+ machines as these can have a relocated vector base, simply changing $6c.w to install a custom VBI for example won't work anymore if VBR is set to any other location than $0, $6c+VBR offset must be used in that case. And this is exactly what happens in these lines of code (a0: VBR): Code: lea .NewVBI(pc),a1 move.l a1,$6c(a0)