bus arbitration fixes

nukeykt · May 4, 2023 · 0d230e7 · 0d230e7
1 parent 3f31082
commit 0d230e7
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Showing 4 changed files with 25 additions and 5 deletions.
diff --git a/68k.c b/68k.c
@@ -2438,6 +2438,8 @@ void M68K_Clock(m68k_t* chip, int clk1, int clk2)
         chip->o_rw = 0;
     else if (chip->rw_l && !chip->w409)
         chip->o_rw = 1;
+    else
+        chip->o_rw = state_z;
 
     if (clk2)
         chip->w362 = chip->w382;

diff --git a/fc1004.c b/fc1004.c
@@ -114,6 +114,7 @@ void FC1004_Clock(fc1004_t *chip, int mclk, uint64_t cycles)
         ((chip->tmss.ext_test_0 && !chip->tmss.ext_test_2) ? chip->vdp.prescaler.mclk_dclk : chip->arb.edclk.ext_edclk);
 
     chip->o_vdata_dir = 0;
+    chip->o_vaddress_dir = 0;
     if (chip->ioc.ext_bc2 && chip->tmss.ext_data_out_en && chip->vdp_data_dir)
     {
         chip->o_vdata_dir |= 0xff;
@@ -132,17 +133,17 @@ void FC1004_Clock(fc1004_t *chip, int mclk, uint64_t cycles)
     if (chip->ioc.ext_bc5 && chip->vdp_address_dir)
     {
         chip->o_vaddress_dir |= 0x7f;
-        chip->o_vaddress |= ~0x7f;
+        chip->o_vaddress &= ~0x7f;
     }
     if (chip->arb.w131 && chip->vdp_address_dir)
     {
         chip->o_vaddress_dir |= 0xfff80;
-        chip->o_vaddress |= ~0xfff80;
+        chip->o_vaddress &= ~0xfff80;
     }
     if (chip->arb.w142 && chip->vdp_address_dir)
     {
         chip->o_vaddress_dir |= 0x700000;
-        chip->o_vaddress |= ~0x700000;
+        chip->o_vaddress &= ~0x700000;
     }
 
     chip->br = 1;

diff --git a/iochip.c b/iochip.c
@@ -389,8 +389,8 @@ void IOC_Clock(iochip_t *chip)
 
     chip->byte_sel = chip->input.ext_cas0 && (chip->input.ext_zaddress_in & 1) == 0;
 
-    chip->arb_w1 = !(chip->io_access && chip->input.ext_m3) && (chip->input.ext_zv || chip->input.ext_cas0) && (chip->input.ext_vz || !chip->input.ext_cas0);
-    chip->arb_w2 = (chip->input.ext_zv || !chip->input.ext_cas0) && (chip->input.ext_vz || chip->input.ext_cas0);
+    chip->arb_w1 = !(chip->io_access && chip->input.ext_m3) && (chip->input.ext_zv || !chip->input.ext_cas0) && (chip->input.ext_vz || chip->input.ext_cas0);
+    chip->arb_w2 = (chip->input.ext_zv || chip->input.ext_cas0) && (chip->input.ext_vz || !chip->input.ext_cas0);
 
     chip->ext_bc1 = chip->input.ext_vz || chip->input.ext_t1;
     chip->ext_bc2 = chip->arb_w1 || chip->input.ext_t1;

diff --git a/md.c b/md.c
@@ -393,8 +393,10 @@ int main(int argc, char *argv[])
                 rw = ym.o_rw;
             if (m68k.o_rw != state_z)
                 rw = m68k.o_rw;
+            iorq = 1;
             if (z80.o_iorq != state_z)
                 iorq = !z80.o_iorq;
+            mreq = 1;
             if (z80.o_mreq != state_z)
                 mreq = !z80.o_mreq;
             if (ym.o_mreq != state_z)
@@ -403,6 +405,8 @@ int main(int argc, char *argv[])
                 wr = ym.o_zwr;
             if (z80.o_wr != state_z)
                 wr = !z80.o_wr;
+            if (ym.o_zrd != state_z)
+                rd = ym.o_zrd;
             if (z80.o_rd != state_z)
                 rd = !z80.o_rd;
 
@@ -506,6 +510,8 @@ int main(int argc, char *argv[])
             ym.i_zwr = wr;
             ym.i_zrd = rd;
             ym.i_m1 = !z80.o_m1;
+            if (ym.o_cas0 != state_z)
+                ym.i_cas0 = ym.o_cas0;
 
             FC1004_Clock(&ym, mcycles & 1, mcycles);
 
@@ -588,6 +594,17 @@ int main(int argc, char *argv[])
             }
         }
 
+#if 0
+        if (m68k.o_rw == state_z)
+        {
+            if ((uds == 0 || lds == 0) && as == 0)
+            {
+                printf("vdp/z80 access ulrw %i%i%i address %x data %x\n",
+                    uds, lds, rw, vaddress*2, vdata);
+            }
+        }
+#endif
+
         // 68k ram
         if (!ym.vdp.o_ras0)
         {