# HG changeset patch
# User Mike Pavone <pavone@retrodev.com>
# Date 1356935981 28800
# Node ID 0e7e1ccc0a817fa610daeb5c7d3a0f15c8f0072e
# Parent  e64554246d11fda6f08e0e8346efc028b122b66d
Implemented HV counter

diff -r e64554246d11 -r 0e7e1ccc0a81 blastem.c
--- a/blastem.c	Sun Dec 30 18:40:33 2012 -0800
+++ b/blastem.c	Sun Dec 30 22:39:41 2012 -0800
@@ -167,8 +167,8 @@
 		} else if(vdp_port < 8) {
 			context->value = vdp_control_port_read(v_context);
 		} else {
-			//TODO: Implement H/V counter
-			context->value = 0;
+			context->value = vdp_hv_counter_read(v_context);
+			//printf("HV Counter: %X at cycle %d\n", context->value, v_context->cycles);
 		}
 		context->current_cycle = v_context->cycles/MCLKS_PER_68K;
 	} else {
diff -r e64554246d11 -r 0e7e1ccc0a81 runtime.S
--- a/runtime.S	Sun Dec 30 18:40:33 2012 -0800
+++ b/runtime.S	Sun Dec 30 22:39:41 2012 -0800
@@ -369,6 +369,8 @@
 	jbe cart_b
 	cmp $0xE00000, %ecx
 	jae workram_b
+	cmp $0xC00000, %ecx
+	jae vdp_psg_b
 	cmp $0xA10000, %ecx
 	jb not_io_b
 	cmp $0xA12000, %ecx
@@ -378,6 +380,17 @@
 	xor %cl, %cl
 	dec %cl
 	ret
+vdp_psg_b:
+	test $0x2700E0, %ecx
+	jnz crash
+	and $0x1F, %ecx
+	bt $0, %ecx
+	jnc vdp_swap
+	jmp do_vdp_port_read
+vdp_swap:
+	call do_vdp_port_read
+	shr $8, %cx
+	ret
 workram_b:
 	/* deal with byte swapping */
 	xor $1, %ecx
diff -r e64554246d11 -r 0e7e1ccc0a81 vdp.c
--- a/vdp.c	Sun Dec 30 18:40:33 2012 -0800
+++ b/vdp.c	Sun Dec 30 22:39:41 2012 -0800
@@ -1092,6 +1092,10 @@
 	if (context->flags & FLAG_DMA_RUN) {
 		value |= 0x20;
 	}
+	uint32_t line= context->cycles / MCLKS_LINE;
+	if (line >= (context->latched_mode & BIT_PAL ? PAL_ACTIVE : NTSC_ACTIVE)) {
+		value |= 0x8;
+	}
 	//TODO: Lots of other bits in status port
 	return value;
 }
@@ -1131,6 +1135,43 @@
 	return value;
 }
 
+uint16_t vdp_hv_counter_read(vdp_context * context)
+{
+	uint32_t line= context->cycles / MCLKS_LINE;
+	if (!line) {
+		line = 0xFF;
+	} else {
+		line--;
+		if (line > 0xEA) {
+			line = (line + 0xFA) & 0xFF;
+		}
+	}
+	uint32_t linecyc = context->cycles % MCLKS_LINE;
+	if (context->latched_mode & BIT_H40) {
+		linecyc /= 8;
+		if (linecyc >= 86) {
+			linecyc -= 86;
+		} else {
+			linecyc += 334;
+		}
+		if (linecyc > 0x16C) {
+			linecyc += 92;
+		}
+	} else {
+		linecyc /= 10;
+		if (linecyc >= 74) {
+			linecyc -= 74;
+		} else {
+			linecyc += 268;
+		}
+		if (linecyc > 0x127) {
+			linecyc += 170;
+		}
+	}
+	linecyc &= 0xFF;
+	return (line << 8) | linecyc;
+}
+
 void vdp_adjust_cycles(vdp_context * context, uint32_t deduction)
 {
 	context->cycles -= deduction;
diff -r e64554246d11 -r 0e7e1ccc0a81 vdp.h
--- a/vdp.h	Sun Dec 30 18:40:33 2012 -0800
+++ b/vdp.h	Sun Dec 30 22:39:41 2012 -0800
@@ -127,6 +127,7 @@
 void vdp_data_port_write(vdp_context * context, uint16_t value);
 uint16_t vdp_control_port_read(vdp_context * context);
 uint16_t vdp_data_port_read(vdp_context * context);
+uint16_t vdp_hv_counter_read(vdp_context * context);
 void vdp_adjust_cycles(vdp_context * context, uint32_t deduction);
 
 #endif //VDP_H_