shithub: sms

Info  •  Files  •  Log  •  Branches

IRQ fixes

--- a/vdp.c

+++ b/vdp.c

@@ -13,18 +13,28 @@

 int vdpx = 0, vdpyy, frame, intla;

 int first = 1;

 u16int hctr;

-static int xmax, xdisp, ydisp;

-enum { ymax = 262, yvbl = 234 };

+static int xmax, xdisp;

+enum { ymax = 262 };

 int vdpy = ymax-1;

 static u8int scrollx;

 static int scrolly;

+static void

+irqupdate(void)

+{

+	z80irq = 0;

+	if((irq & INTHOR) != 0 && (reg[MODE1] & IE1) != 0)

+		z80irq = 1;

+	if((irq & INTVBL) != 0 && (reg[MODE2] & IE0) != 0)

+		z80irq = 1;

+}

+

 void

 vdpmode(void)

 {

 	xmax = 320;

 	xdisp = 256;

-	ydisp = 224;

+	hctr = reg[HORCTR];

 }

 static void

@@ -172,7 +182,14 @@

 			vdpaddr++;

 			vdpaddr &= 0x3fff;

 			break;

-		case 2: reg[v & 0x0f] = (vdpaddr & 0x00ff); break;

+		case 2:

+			reg[v & 0x0f] = (vdpaddr & 0x00ff);

+			if((v & 0x0f) == MODE1 && (reg[MODE1] & IE1) == 0)

+				irq &= ~INTHOR;

+			if((v & 0x0f) == MODE2 && (reg[MODE2] & IE0) == 0)

+				irq &= ~INTVBL;

+			irqupdate();

+			break;

 	}

 }

@@ -211,7 +228,8 @@

 	v = vdpstat | 0x1f;

 	vdpstat = 0;

-	z80irq = 0;

+	irq = 0;

+	irqupdate();

 	first = 1;

 	return v;

 }

@@ -225,7 +243,9 @@

 u8int

 vdpvcounter(void)

 {

-	if (vdpy > 0xda)

+	int disph = ((reg[MODE1] & 0x06) == 0x06) && ((reg[MODE2] & 0x18) == 0x10) ? 224 : 192;

+	int wrap = disph == 224 ? 0xea : 0xda;

+	if (vdpy > wrap)

 		return vdpy - 0x06;

 	return vdpy;

 }

@@ -246,31 +266,27 @@

 		if(vdpx == xdisp - 1) sprites();

 	}

 	if(++vdpx >= xmax){

-		z80irq = 0;

 		vdpx = 0;

 		if(++vdpy >= ymax){

 			vdpy = 0;

 			scrolly = reg[VERSCR];

-			irq &= ~INTVBL;

-			vdpstat &= ~(STATINT | STATOVR | STATCOLL);

 			flush();

 		}

 		if(intla)

 			vdpyy = vdpy << 1 | frame;

-		if(vdpy == 0 || vdpy > disph)

-			hctr = reg[HORCTR];

-		else

+		if(vdpy <= disph){

 			if(hctr-- == 0){

-				if((reg[MODE1] & IE1) != 0)

-					irq |= INTHOR;

+				irq |= INTHOR;

+				irqupdate();

 				hctr = reg[HORCTR];

 			}

-		if(vdpy == yvbl){

+		}else

+			hctr = reg[HORCTR];

+		if(vdpy == disph + 1){

 			vdpstat |= STATINT;

 			frame ^= 1;

-			z80irq = 1;

-			if((reg[MODE2] & IE0) != 0)

-				irq |= INTVBL;

+			irq |= INTVBL;

+			irqupdate();

 		}

+		}

 	}

-}

--- a/z80.c

+++ b/z80.c

@@ -5,6 +5,7 @@

 #include "fns.h"

 u8int ipage, intm, z80irq;

+static u8int afterei;

 u16int ix[2];

 u16int spc, scurpc;

 u16int sp = 0xdff0;

@@ -781,6 +782,8 @@

 		scurpc = spc = 0;

 		intm = 0;

 		ipage = 0;

+		afterei = 0;

+		halt = 0;

 		return 1;

 	}

 	if((z80bus & BUSACK) != 0){

@@ -792,17 +795,23 @@

 		z80bus |= BUSACK;

 		return 1;

 	}

-	if(z80irq != 0 && (intm & 0x80) != 0){

+	u8int skipirq = afterei;

+	if(skipirq)

+		afterei = 0;

+	if(z80irq != 0 && (intm & 0x80) != 0 && !skipirq){

+		halt = 0;

 		push16(spc);

 		intm &= 0x3f;

 		switch(intm & 3){

 		case 1:

 			spc = 0x38;

-			return 2;

+			return 13;

 		default:

 			sysfatal("z80 interrupt in mode %d", intm & 3);

 		}

 	}

+	if(halt)

+		return 4;

 	scurpc = spc;

 	if(0)

 		print("%x AF %.2x%.2x BC %.2x%.2x DE %.2x%.2x HL %.2x%.2x IX %.4x IY %.4x\n", scurpc, s[rA], s[rF], s[rB], s[rC], s[rD], s[rE], s[rH], s[rL], ix[0], ix[1]);

@@ -942,7 +951,7 @@

 		s[rH] = z80read(sp + 1);

 		write16(sp, v);

 		return 19;

-	case 0xf3: intm &= 0x3f; return 4;

+	case 0xf3: intm &= 0x3f; afterei = 0; return 4;

 	case 0xc4: return call(fetch16(), (s[rF] & FLAGZ) == 0);

 	case 0xd4: return call(fetch16(), (s[rF] & FLAGC) == 0);

 	case 0xe4: return call(fetch16(), (s[rF] & FLAGV) == 0);

@@ -989,7 +998,7 @@

 		s[rH] = v >> 8;

 		s[rL] = v;

 		return 4;

-	case 0xfb: intm |= 0xc0; return 4;

+	case 0xfb: intm |= 0xc0; afterei = 1; return 4;

 	case 0xcc: return call(fetch16(), (s[rF] & FLAGZ) != 0);

 	case 0xdc: return call(fetch16(), (s[rF] & FLAGC) != 0);

 	case 0xec: return call(fetch16(), (s[rF] & FLAGV) != 0);

@@ -1016,7 +1025,10 @@

 	scurpc = spc = 0;

 	intm = 0;

 	ipage = 0;

+	afterei = 0;

 	sp = 0xdff0;

+	halt = 0;

+	inplast = 0;

 	s[rA] = 0x00;

 	s[rF] = 0x40;

-- 

⑨