switch DMNA Silpheed hack to timeslice hack

[picodrive.git] / pico / cd / memory.c

diff --git a/pico/cd/memory.c b/pico/cd/memory.c
index 593a4cb..32c9515 100644 (file)
--- a/pico/cd/memory.c
+++ b/pico/cd/memory.c
@@ -27,6 +27,7 @@ typedef unsigned int   u32;
 #define rdprintf(...)\r
 //#define wrdprintf dprintf\r
 #define wrdprintf(...)\r
+//#define r3printf elprintf\r
 #define r3printf(...)\r
 #endif\r
 \r
@@ -57,8 +58,6 @@ static u32 m68k_reg_read16(u32 a)
       goto end;\r
     case 2:\r
       d = (Pico_mcd->s68k_regs[a]<<8) | (Pico_mcd->s68k_regs[a+1]&0xc7);\r
-      // the DMNA delay must only be visible on s68k side (Lunar2, Silpheed)\r
-      if (Pico_mcd->m.state_flags&2) { d &= ~1; d |= 2; }\r
       r3printf(EL_STATUS, "m68k_regs r3: %02x @%06x", (u8)d, SekPc);\r
       goto end;\r
     case 4:\r
@@ -109,8 +108,8 @@ void m68k_reg_write8(u32 a, u32 d)
     case 1:\r
       d &= 3;\r
       if (!(d&1)) Pico_mcd->m.state_flags |= 1; // reset pending, needed to be sure we fetch the right vectors on reset\r
-      if ( (Pico_mcd->m.busreq&1) != (d&1)) dprintf("m68k: s68k reset %i", !(d&1));\r
-      if ( (Pico_mcd->m.busreq&2) != (d&2)) dprintf("m68k: s68k brq %i", (d&2)>>1);\r
+      if ( (Pico_mcd->m.busreq&1) != (d&1)) elprintf(EL_INTSW, "m68k: s68k reset %i", !(d&1));\r
+      if ( (Pico_mcd->m.busreq&2) != (d&2)) elprintf(EL_INTSW, "m68k: s68k brq %i", (d&2)>>1);\r
       if ((Pico_mcd->m.state_flags&1) && (d&3)==1) {\r
         SekResetS68k(); // S68k comes out of RESET or BRQ state\r
         Pico_mcd->m.state_flags&=~1;\r
@@ -131,20 +130,14 @@ void m68k_reg_write8(u32 a, u32 d)
       //if ((Pico_mcd->s68k_regs[3]&4) != (d&4)) dprintf("m68k: ram mode %i mbit", (d&4) ? 1 : 2);\r
       //if ((Pico_mcd->s68k_regs[3]&2) != (d&2)) dprintf("m68k: %s", (d&4) ? ((d&2) ? "word swap req" : "noop?") :\r
       //                                             ((d&2) ? "word ram to s68k" : "word ram to m68k"));\r
-      if (dold & 4) {\r
-        d ^= 2;                // writing 0 to DMNA actually sets it, 1 does nothing\r
+      if (dold & 4) {   // 1M mode\r
+        d ^= 2;         // writing 0 to DMNA actually sets it, 1 does nothing\r
       } else {\r
-        //dold &= ~2; // ??\r
-#if 1\r
-       if (d & (d ^ dold) & 2) { // DMNA is being set\r
-          Pico_mcd->m.state_flags |= 2; // we must delay setting DMNA bit (needed for Silpheed)\r
-          d &= ~2;\r
-       }\r
-        else\r
-          Pico_mcd->m.state_flags &= ~2;\r
-#else\r
-        if (d & 2) dold &= ~1; // return word RAM to s68k in 2M mode\r
-#endif\r
+       if ((d ^ dold) & d & 2) { // DMNA is being set\r
+          dold &= ~1;   // return word RAM to s68k\r
+          /* Silpheed hack: bset(w3), r3, btst, bne, r3 */\r
+          SekEndRun(20+16+10+12+16);\r
+        }\r
       }\r
       Pico_mcd->s68k_regs[3] = d | dold; // really use s68k side register\r
 #ifdef USE_POLL_DETECT\r
@@ -324,9 +317,9 @@ void s68k_reg_write8(u32 a, u32 d)
         }\r
         else\r
           d |= dold&1;\r
+        // s68k can only set RET, writing 0 has no effect\r
         if (d&1) d &= ~2; // return word RAM to m68k in 2M mode\r
       }\r
-      Pico_mcd->m.state_flags &= ~2;\r
       break;\r
     }\r
     case 4:\r