md board: zd bus pullup, za/va buskeepers

nukeykt · Aug 13, 2023 · b96b912 · b96b912
1 parent dee7893
commit b96b912
Showing 1 changed file with 6 additions and 3 deletions.
diff --git a/md_board.v b/md_board.v
@@ -617,16 +617,19 @@ module md_board
 		VA <=
 			(~ym_VA_d & ym_VA_o) |
 			(~m68k_VA_d & m68k_VA_o) |
-			(~m3_cart_VA_d & m3_cart_VA_o);
+			(~m3_cart_VA_d & m3_cart_VA_o) |
+			((ym_VA_d & m68k_VA_d & m3_cart_VA_d) & VA);
 
 		ZD <=
 			(~ym_ZD_d & ym_ZD_o) |
 			(~z80_ZD_d & z80_ZD_o) |
-			(~ram_ZD_d & ram_z80_o);
+			(~ram_ZD_d & ram_z80_o) |
+			((ym_ZD_d & z80_ZD_d & z80_ZD_d) & 8'hff);
 
 		ZA <=
 			(~ym_ZA_d & ym_ZA_o) |
-			(~z80_ZA_d & z80_ZA_o);
+			(~z80_ZA_d & z80_ZA_o) |
+			((ym_ZA_d & z80_ZA_d) & ZA);
 
 		DTACK <= ~ym_DTACK_pull & ~ext_dtack;