Do not write to unknown or strobe or read-only registers.

diff --git a/utilities/stateload/main.c b/utilities/stateload/main.c
index e152eff3ab4d64076fccee531a62a032635182b1..a120e1cee367b2f071a00a661f79446d3c697eef 100644 (file)
--- a/utilities/stateload/main.c
+++ b/utilities/stateload/main.c
@@ -205,14 +205,58 @@ static void set_custom(UBYTE *p)
                if (i >= 0xa0 && i < 0xe0)
                        continue;
 
-               // skip blitter start, DMACON and INTENA
-               if (i == 0x58 || i == 0x5e || i == 0x96 || i == 0x9a) {
+               // skip blitter start, DMACON, INTENA, registers
+               // that are write strobed, unused registers.
+               switch(i)
+               {
+                       case 0x00:
+                       case 0x02:
+                       case 0x04:
+                       case 0x06:
+                       case 0x08:
+                       case 0x10:
+                       case 0x16:
+                       case 0x18:
+                       case 0x1a:
+                       case 0x1c:
+                       case 0x1e:
+                       case 0x24: // DSKLEN
+                       case 0x26:
+                       case 0x28:
+                       case 0x2a: // VPOSW
+                       case 0x2c: // VHPOSW
+                       case 0x30:
+                       case 0x38:
+                       case 0x3a:
+                       case 0x3c:
+                       case 0x3e:
+                       case 0x58:
+                       case 0x5e:
+                       case 0x68:
+                       case 0x6a:
+                       case 0x6c:
+                       case 0x6e:
+                       case 0x76:
+                       case 0x78:
+                       case 0x7a:
+                       case 0x7c:
+                       case 0x88:
+                       case 0x8a:
+                       case 0x8c:                      
+                       case 0x96: // DMACON
+                       case 0x9a: // INTENA
+                       case 0x9c: // INTREQ
                        p += 2;
                        continue;
                }
 
                // skip programmed sync registers except BEAMCON0
-               if (i >= 0x1c0 && i != 0x1fc && i != 0x1dc) {
+               if (i >= 0x1c0 && i < 0x1e4 && i != 0x1dc) {
+                       p += 2;
+                       continue;
+               }
+               // skip unused
+               if (i >= 0x1e6 && i < 0x1fc) {
                        p += 2;
                        continue;
                }
@@ -237,6 +281,7 @@ void set_custom_final(UBYTE *p)
        c->intena = 0x7fff;
        c->intreq = 0x7fff;
        c->dmacon = 0x7fff;
+       c->vposw = getword(p, 4 + 0x04) & 0x8000; // LOF
        c->dmacon = getword(p, 4 + 0x96) | 0x8000;
        c->intena = getword(p, 4 + 0x9a) | 0x8000;
        c->intreq = getword(p, 4 + 0x9c) | 0x8000;