fast dma

[picodrive.git] / Pico / VideoPort.c

diff --git a/Pico/VideoPort.c b/Pico/VideoPort.c
index b7a05f0..e3643df 100644 (file)
--- a/Pico/VideoPort.c
+++ b/Pico/VideoPort.c
@@ -139,15 +139,24 @@ static void DmaSlow(int len)
   {\r
     case 1: // vram\r
       r = Pico.vram;\r
-      for(; len; len--)\r
+      if (inc == 2 && !(a&1) && a+len*2 < 0x10000)\r
       {\r
-        d=*pd++;\r
-        if(a&1) d=(d<<8)|(d>>8);\r
-        r[a>>1] = (u16)d; // will drop the upper bits\r
-        // AutoIncrement\r
-        a=(u16)(a+inc);\r
-        // didn't src overlap?\r
-        //if(pd >= pdend) pd-=0x8000; // should be good for RAM, bad for ROM\r
+        // most used DMA mode\r
+       memcpy16(r + (a>>1), pd, len);\r
+       a += len*2;\r
+      }\r
+      else\r
+      {\r
+        for(; len; len--)\r
+        {\r
+          d=*pd++;\r
+          if(a&1) d=(d<<8)|(d>>8);\r
+          r[a>>1] = (u16)d; // will drop the upper bits\r
+          // AutoIncrement\r
+          a=(u16)(a+inc);\r
+          // didn't src overlap?\r
+          //if(pd >= pdend) pd-=0x8000; // should be good for RAM, bad for ROM\r
+        }\r
       }\r
       rendstatus|=0x10;\r
       break;\r