The-Homebrew-Cloud/Genesis-Plus-GX
2
0
Fork 0
mirror of https://github.com/ekeeke/Genesis-Plus-GX.git synced 2024-09-10 16:53:15 +02:00
Code Issues Packages Projects Releases Wiki Activity

fixed VDP DMA from SVP ROM latency, broken in r683 (graphic errors in Virtua Racing)

Browse Source
This commit is contained in:
EkeEke 2012-11-21 22:37:46 +01:00
parent 27bbffdffb
commit 1ace7445f6
1 changed files with 2 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
source/vdp_ctrl.c
View File

@ -745,8 +745,8 @@ void vdp_68k_ctrl_w(unsigned int data)
/* DMA source address */
dma_src = (reg[22] << 8) | reg[21];
/* Transfer from SVP DRAM ($300000-$31ffff) or CD Word-RAM ($200000-$3fffff/$600000-$7fffff) */
if (((system_hw == SYSTEM_MCD) && ((reg[23] & 0x70) == ((scd.cartridge.boot >> 1) + 0x10))) || (svp && ((reg[23] & 0x70) == 0x10)))
/* Transfer from SVP ROM/RAM ($000000-$3fffff) or CD Word-RAM ($200000-$3fffff/$600000-$7fffff) */
if (((system_hw == SYSTEM_MCD) && ((reg[23] & 0x70) == ((scd.cartridge.boot >> 1) + 0x10))) || (svp && !(reg[23] & 0x60)))
{
/* source data is available with one cycle delay, i.e first word written by VDP is */
/* previous data being held on 68k bus at that time, then source words are written */