rework sr

[picodrive.git] / pico / videoport.c

diff --git a/pico/videoport.c b/pico/videoport.c
index 22b8385..b5e3f86 100644 (file)
--- a/pico/videoport.c
+++ b/pico/videoport.c
@@ -376,8 +376,7 @@ PICO_INTERNAL_ASM void PicoVideoWrite(unsigned int a,unsigned short d)
       pvid->pending=0;\r
     }\r
 \r
-    // preliminary FIFO emulation for Chaos Engine, The (E)\r
-    if (!(pvid->status & SR_VB) && (pvid->reg[1] & 0x40) && !(PicoOpt&POPT_DIS_VDP_FIFO)) // active display?\r
+    if (!(pvid->status & SR_VB) && !(PicoOpt&POPT_DIS_VDP_FIFO))\r
     {\r
       int use = pvid->type == 1 ? 2 : 1;\r
       pvid->lwrite_cnt -= use;\r
@@ -434,6 +433,9 @@ PICO_INTERNAL_ASM void PicoVideoWrite(unsigned int a,unsigned short d)
           case 0x01:\r
             elprintf(EL_INTSW, "vint_onoff: %i->%i [%u] pend=%i @ %06x", (dold&0x20)>>5,\r
                     (d&0x20)>>5, SekCyclesDone(), (pvid->pending_ints&0x20)>>5, SekPc);\r
+            if (!(pvid->status & PVS_VB2))\r
+              pvid->status &= ~SR_VB;\r
+            pvid->status |= ((d >> 3) ^ SR_VB) & SR_VB; // forced blanking\r
             goto update_irq;\r
           case 0x05:\r
             //elprintf(EL_STATUS, "spritep moved to %04x", (unsigned)(Pico.video.reg[5]&0x7f) << 9);\r
@@ -503,25 +505,25 @@ update_irq:
   }\r
 }\r
 \r
-PICO_INTERNAL_ASM unsigned int PicoVideoRead(unsigned int a)\r
+static u32 SrLow(const struct PicoVideo *pv)\r
 {\r
-  a&=0x1c;\r
+  unsigned int c, d = pv->status;\r
 \r
-  if (a==0x04) // control port\r
-  {\r
-    struct PicoVideo *pv=&Pico.video;\r
-    unsigned int d;\r
-    d=pv->status;\r
-    //if (PicoOpt&POPT_ALT_RENDERER) d|=0x0020; // sprite collision (Shadow of the Beast)\r
-    if (SekCyclesDone() - Pico.t.m68c_line_start >= 488-88)\r
-      d|=0x0004; // H-Blank (Sonic3 vs)\r
-\r
-    d |= ((pv->reg[1]&0x40)^0x40) >> 3;  // set V-Blank if display is disabled\r
-    d |= (pv->pending_ints&0x20)<<2;     // V-int pending?\r
-    if (d&0x100) pv->status&=~0x100; // FIFO no longer full\r
+  c = SekCyclesDone() - Pico.t.m68c_line_start - 39;\r
+  if (c < 92)\r
+    d |= SR_HB;\r
+  return d;\r
+}\r
 \r
-    pv->pending = 0; // ctrl port reads clear write-pending flag (Charles MacDonald)\r
+PICO_INTERNAL_ASM unsigned int PicoVideoRead(unsigned int a)\r
+{\r
+  a &= 0x1c;\r
 \r
+  if (a == 0x04) // control port\r
+  {\r
+    struct PicoVideo *pv = &Pico.video;\r
+    unsigned int d = SrLow(pv);\r
+    pv->pending = 0;\r
     elprintf(EL_SR, "SR read: %04x [%u] @ %06x", d, SekCyclesDone(), SekPc);\r
     return d;\r
   }\r
@@ -572,12 +574,9 @@ unsigned char PicoVideoRead8DataL(void)
   return VideoRead();\r
 }\r
 \r
-// FIXME: broken mess\r
 unsigned char PicoVideoRead8CtlH(void)\r
 {\r
   u8 d = (u8)(Pico.video.status >> 8);\r
-  if (d & 1)\r
-    Pico.video.status &= ~0x100; // FIFO no longer full\r
   Pico.video.pending = 0;\r
   elprintf(EL_SR, "SR read (h): %02x @ %06x", d, SekPc);\r
   return d;\r
@@ -585,11 +584,7 @@ unsigned char PicoVideoRead8CtlH(void)
 \r
 unsigned char PicoVideoRead8CtlL(void)\r
 {\r
-  u8 d = (u8)Pico.video.status;\r
-  //if (PicoOpt&POPT_ALT_RENDERER) d|=0x0020; // sprite collision (Shadow of the Beast)\r
-  d |= ((Pico.video.reg[1]&0x40)^0x40) >> 3;  // set V-Blank if display is disabled\r
-  d |= (Pico.video.pending_ints&0x20)<<2;     // V-int pending?\r
-  if (SekCyclesDone() - Pico.t.m68c_line_start >= 488-88) d |= 4;    // H-Blank\r
+  u8 d = SrLow(&Pico.video);\r
   Pico.video.pending = 0;\r
   elprintf(EL_SR, "SR read (l): %02x @ %06x", d, SekPc);\r
   return d;\r