Some PPI changes, should make the PPI behave consistently on hard reset.

src/cpu_common/808x.c

@@ -34,6 +34,7 @@
 #include <86box/rom.h>
 #include <86box/nmi.h>
 #include <86box/pic.h>
+#include <86box/ppi.h>
 #include <86box/timer.h>
 
 /* The opcode of the instruction currently being executed. */
@@ -978,8 +979,10 @@ reset_common(int hard)
     in_smm = smi_latched = 0;
     smi_line = smm_in_hlt = 0;
 
-    if (hard)
+    if (hard) {
 	smbase = 0x00030000;
+	ppi_reset();
+    }
     in_sys = 0;
 }
 

src/keyboard_at.c

@@ -2039,7 +2039,7 @@ do_command:
 		break;
 
 	case 0x61:
-		ppi.pb = val;
+		ppi.pb = (ppi.pb & 0x10) | (val & 0x0f);
 
 		speaker_update();
 		speaker_gated = val & 1;

src/ppi.c

@@ -20,8 +20,8 @@ PPI ppi;
 int ppispeakon;
 
 
-void ppi_reset(void)
+void
+ppi_reset(void)
 {
-        ppi.pa=0x0;
-        ppi.pb=0x40;
+    memset(&ppi, 0x00, sizeof(PPI));
 }