some support for 128k mode

[picodrive.git] / pico / videoport.c

diff --git a/pico/videoport.c b/pico/videoport.c
index 3f26d58..b14e70f 100644 (file)
--- a/pico/videoport.c
+++ b/pico/videoport.c
@@ -29,6 +29,13 @@ static __inline void AutoIncrement(void)
   Pico.video.addr=(unsigned short)(Pico.video.addr+Pico.video.reg[0xf]);\r
 }\r
 \r
+static NOINLINE void VideoWrite128(u32 a, u16 d)\r
+{\r
+  // nasty\r
+  a = ((a & 2) >> 1) | ((a & 0x400) >> 9) | (a & 0x3FC) | ((a & 0x1F800) >> 1);\r
+  ((u8 *)Pico.vram)[a] = d;\r
+}\r
+\r
 static void VideoWrite(u16 d)\r
 {\r
   unsigned int a=Pico.video.addr;\r
@@ -43,6 +50,10 @@ static void VideoWrite(u16 d)
     case 3: Pico.m.dirtyPal = 1;\r
             Pico.cram [(a>>1)&0x003f]=d; break; // wraps (Desert Strike)\r
     case 5: Pico.vsram[(a>>1)&0x003f]=d; break;\r
+    case 0x81:\r
+      a |= Pico.video.addr_u << 16;\r
+      VideoWrite128(a, d);\r
+      break;\r
     //default:elprintf(EL_ANOMALY, "VDP write %04x with bad type %i", d, Pico.video.type); break;\r
   }\r
 \r
@@ -186,6 +197,17 @@ static void DmaSlow(int len, unsigned int source)
       }\r
       break;\r
 \r
+    case 0x81: // vram 128k\r
+      a |= Pico.video.addr_u << 16;\r
+      for(; len; len--)\r
+      {\r
+        VideoWrite128(a, base[source++ & mask]);\r
+        // AutoIncrement\r
+        a = (a + inc) & 0x1ffff;\r
+      }\r
+      Pico.video.addr_u = a >> 16;\r
+      break;\r
+\r
     default:\r
       if (Pico.video.type != 0 || (EL_LOGMASK & EL_VDPDMA))\r
         elprintf(EL_VDPDMA|EL_ANOMALY, "DMA with bad type %i", Pico.video.type);\r
@@ -303,20 +325,23 @@ static NOINLINE void CommandDma(void)
   Pico.video.reg[0x16] = source >> 8;\r
 }\r
 \r
-static void CommandChange(void)\r
+static NOINLINE void CommandChange(void)\r
 {\r
-  struct PicoVideo *pvid=&Pico.video;\r
-  unsigned int cmd=0,addr=0;\r
+  struct PicoVideo *pvid = &Pico.video;\r
+  unsigned int cmd, addr;\r
 \r
-  cmd=pvid->command;\r
+  cmd = pvid->command;\r
 \r
   // Get type of transfer 0xc0000030 (v/c/vsram read/write)\r
-  pvid->type=(unsigned char)(((cmd>>2)&0xc)|(cmd>>30));\r
+  pvid->type = (u8)(((cmd >> 2) & 0xc) | (cmd >> 30));\r
+  if (pvid->type == 1) // vram\r
+    pvid->type |= pvid->reg[1] & 0x80; // 128k\r
 \r
   // Get address 0x3fff0003\r
-  addr =(cmd>>16)&0x3fff;\r
-  addr|=(cmd<<14)&0xc000;\r
-  pvid->addr=(unsigned short)addr;\r
+  addr  = (cmd >> 16) & 0x3fff;\r
+  addr |= (cmd << 14) & 0xc000;\r
+  pvid->addr = (u16)addr;\r
+  pvid->addr_u = (u8)((cmd >> 2) & 1);\r
 }\r
 \r
 static void DrawSync(int blank_on)\r