Disabled the DRAM row emulation on the 420EX and SiS 496/497, should fix memory with machines using those chipsets.

src/chipset/intel_420ex.c

@@ -15,6 +15,7 @@
  *
  *          Copyright 2020 Miran Grca.
  */
+#define USE_DRB_HACK
 #include <stdarg.h>
 #include <stdint.h>
 #include <stdio.h>

src/chipset/sis_85c496.c

@@ -14,6 +14,7 @@
  *
  *          Copyright 2019-2020 Miran Grca.
  */
+#define USE_DRB_HACK
 #include <stdarg.h>
 #include <stdio.h>
 #include <stdint.h>