From fd8924f7935be93827e380fd1bbef64d88ab6b2d Mon Sep 17 00:00:00 2001 From: Aaron Giles Date: Mon, 20 Feb 2012 08:41:18 +0000 Subject: [PATCH] Williams blits with bit 2 set take approximately 2x as long because they are bus-shared with RAM. Should impact some timing behaviors such as later levels in Robotron, where approximately 10% of the blits are done with bit 2 set. Further refinements may be necessary but this addresses the most significant issue. [Sean Riddle, Aaron Giles] --- src/mame/video/williams.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/mame/video/williams.c b/src/mame/video/williams.c index 7a38f9a441a..871d4264cce 100644 --- a/src/mame/video/williams.c +++ b/src/mame/video/williams.c @@ -542,7 +542,7 @@ WRITE8_HANDLER( williams_blitter_w ) /* based on the number of memory accesses needed to do the blit, compute how long the blit will take */ /* this is just a guess */ - estimated_clocks_at_4MHz = 20 + 2 * accesses; + estimated_clocks_at_4MHz = 20 + ((data & 4) ? 4 : 2) * accesses; device_adjust_icount(&space->device(), -((estimated_clocks_at_4MHz + 3) / 4)); /* Log blits */