Implemented basic interrupt support in Z80 core.

1 files changed, 21 insertions, 2 deletions

diff --git a/transz80.c b/transz80.c
index 897adee..afe99fd 100644
--- a/transz80.c
+++ b/transz80.c
@@ -1,12 +1,19 @@
 #include "z80inst.h"
 #include "z80_to_x86.h"
 #include "mem.h"
+#include "vdp.h"
 #include <stdio.h>
 #include <stdlib.h>
 
 uint8_t z80_ram[0x2000];
 uint16_t cart[0x200000];
 
+#define MCLKS_PER_Z80 15
+//TODO: Figure out the exact value for this
+#define MCLKS_PER_FRAME (MCLKS_LINE*262)
+#define VINT_CYCLE ((MCLKS_LINE * 226)/MCLKS_PER_Z80)
+#define CYCLE_NEVER 0xFFFFFFFF
+
 int main(int argc, char ** argv)
 {
 	long filesize;
@@ -38,18 +45,30 @@ int main(int argc, char ** argv)
 		fseek(f, 0, SEEK_SET);
 		fread(cart, 1, filesize < sizeof(cart) ? filesize : sizeof(cart), f);
 		fclose(f);
+		for(unsigned short * cur = cart; cur - cart < (filesize/2); ++cur)
+		{
+			*cur = (*cur >> 8) | (*cur << 8);
+		}
 	}
 	init_x86_z80_opts(&opts);
 	init_z80_context(&context, &opts);
 	//Z80 RAM
 	context.mem_pointers[0] = z80_ram;
-	context.sync_cycle = context.target_cycle = 0x7FFFFFFF;
+	context.sync_cycle = context.target_cycle = MCLKS_PER_FRAME/MCLKS_PER_Z80;
+	context.int_cycle = CYCLE_NEVER;
 	//cartridge/bank
-	context.mem_pointers[1] = context.mem_pointers[2] = cart;
+	context.mem_pointers[1] = context.mem_pointers[2] = (uint8_t *)cart;
 	z80_reset(&context);
 	for(;;)
 	{
 		z80_run(&context);
+		if (context.current_cycle >= MCLKS_PER_FRAME/MCLKS_PER_Z80) {
+			context.current_cycle -= MCLKS_PER_FRAME/MCLKS_PER_Z80;
+		}
+		if (context.current_cycle < VINT_CYCLE && context.iff1) {
+			context.int_cycle = VINT_CYCLE;
+		}
+		context.target_cycle = context.sync_cycle < context.int_cycle ? context.sync_cycle : context.int_cycle;
 	}
 	return 0;
 }