# HG changeset patch
# User Michael Pavone <pavone@retrodev.com>
# Date 1492498701 25200
# Node ID 0849e9356bfe55460da63f6a91447a835f688e83
# Parent  df3d690cb2c334622887017bb2990868b4577c41
Fix time 68K is locked out of bus when doing a 128KB VRAM mode DMA transfer. Fixes a number of problems in Overdrive 2

diff -r df3d690cb2c3 -r 0849e9356bfe vdp.c
--- a/vdp.c	Mon Apr 17 20:54:33 2017 -0700
+++ b/vdp.c	Mon Apr 17 23:58:21 2017 -0700
@@ -2432,9 +2432,12 @@
 			dmalen = 0x10000;
 		}
 		uint32_t min_dma_complete = dmalen * (context->regs[REG_MODE_4] & BIT_H40 ? 16 : 20);
-		if ((context->regs[REG_DMASRC_H] & 0xC0) == 0xC0 || (context->cd & 0xF) == VRAM_WRITE) {
+		if (
+			(context->regs[REG_DMASRC_H] & 0xC0) == 0xC0 
+			|| (((context->cd & 0xF) == VRAM_WRITE) && !(context->regs[REG_MODE_2] & BIT_128K_VRAM))) {
 			//DMA copies take twice as long to complete since they require a read and a write
 			//DMA Fills and transfers to VRAM also take twice as long as it requires 2 writes for a single word
+			//unless 128KB mode is enabled
 			min_dma_complete *= 2;
 		}
 		min_dma_complete += context->cycles;