Changed lib6502 to use scan lines and cycles-per-scanline as video fr…

…ame timing

lib6502/6502-emu_wrapper.c

@@ -6,6 +6,7 @@
 #include "libdebugger.h"
 #include "libudis.h"
 
+uint16_t cycles_per_scan_line;
 long cycles_per_frame;
 
 int apple2_mode = 0;
@@ -28,7 +29,7 @@ void lib6502_init_debug_kernel() {
 	PC = 0xf000;
 }
 
-void lib6502_init_cpu(float frequency_mhz, float refresh_rate_hz) {
+void lib6502_init_cpu(int scan_lines, int cycles_per) {
 	init_tables();
 
 	A = 0;
@@ -39,19 +40,30 @@ void lib6502_init_cpu(float frequency_mhz, float refresh_rate_hz) {
 	PC = 0xfffe;
 	memset(memory, 0, sizeof(memory));
 
-	cycles_per_frame = (long)((frequency_mhz * 1000000.0) / refresh_rate_hz);
+	cycles_per_scan_line = cycles_per;
+	cycles_per_frame = (long)(scan_lines * cycles_per_scan_line);
 
 	lib6502_init_debug_kernel();
 }
 
 void lib6502_clear_state_arrays(void *input, output_t *output) {
 	frame_status_t *status = &output->status;
 
+	status->frame_number = 0;
 	status->frame_status = 0;
 	status->cycles_since_power_on = 0;
 	status->instructions_since_power_on = 0;
+	status->cycles_user = 0;
+	status->instructions_user = 0;
+	status->current_instruction_in_frame = 0;
 	status->use_memory_access = 1;
 	status->brk_into_debugger = 1;
+
+	status->final_cycle_in_frame = cycles_per_frame - 1;
+
+	// Initialize frame cycle count at max so first frame cycle count will
+	// start at zero
+	status->current_cycle_in_frame = cycles_per_frame - 1;
 }
 
 void lib6502_configure_state_arrays(void *input, output_t *output) {
@@ -108,8 +120,9 @@ int lib6502_show_current_instruction(history_6502_t *entry)
 int lib6502_step_cpu(frame_status_t *status, history_6502_t *entry, breakpoints_t *breakpoints)
 {
 	int count, bpid;
-	uint8_t last_sp, opcode;
+	uint8_t last_sp, opcode, cycles;
 	intptr_t index;
+	uint16_t line;
 	history_breakpoint_t *b;
 
 	last_pc = PC;
@@ -118,8 +131,13 @@ int lib6502_step_cpu(frame_status_t *status, history_6502_t *entry, breakpoints_
 	opcode = memory[PC];
 	inst = instructions[opcode];
 	count = lengths[inst.mode];
-	if (entry) lib6502_show_current_instruction(entry);
-
+	if (entry) {
+		lib6502_show_current_instruction(entry);
+		line = status->current_cycle_in_frame / cycles_per_scan_line;
+		cycles = status->current_cycle_in_frame % cycles_per_scan_line;
+		entry->scan_line = line;
+		entry->clock_cycle_in_scan_line = line > 255 ? cycles | 0x80 : cycles;
+	}
 	bpid = libdebugger_check_breakpoints(breakpoints, status, &lib6502_register_callback, opcode == 0x4c);
 	if (bpid >= 0) {
 		status->frame_status = FRAME_BREAKPOINT;
@@ -379,7 +397,6 @@ int lib6502_next_frame(input_t *input, output_t *output, breakpoints_t *breakpoi
 	if (apple2_mode) {
 		memory[0xc000] = input->keychar;
 	}
-	status->final_cycle_in_frame = cycles_per_frame - 1;
 	bpid = libdebugger_calc_frame(&lib6502_calc_frame, memory, (frame_status_t *)output, breakpoints, history);
 	lib6502_get_current_state(output);
 	return bpid;

lib6502/6502-emu_wrapper.h

@@ -72,7 +72,7 @@ extern long cycles_per_frame;
 
 /* library functions defined in lib6502.c */
 
-void lib6502_init_cpu(float frequency_mhz, float refresh_rate_hz);
+void lib6502_init_cpu(int scan_lines, int cycles_per_scan_line);
 
 void lib6502_get_current_state(output_t *output);
 

lib6502/lib6502.pyx

@@ -2,7 +2,7 @@ import numpy as np
 cimport numpy as np
 
 cdef extern:
-    int lib6502_init_cpu(float, float)
+    int lib6502_init_cpu(int, int)
     int lib6502_clear_state_arrays(np.uint8_t *buf, np.uint8_t *buf)
     int lib6502_configure_state_arrays(np.uint8_t *buf, np.uint8_t *buf)
     int lib6502_next_frame(np.uint8_t *buf, np.uint8_t *buf, np.uint8_t *buf, np.uint8_t *buf)
@@ -12,7 +12,7 @@ cdef extern:
     void lib6502_set_a2_emulation_mode(np.uint8_t value)
 
 def start_emulator(args):
-    lib6502_init_cpu(1.023, 60.0)  # apple 2 speed
+    lib6502_init_cpu(262, 65)  # apple 2 speed
 
 def clear_state_arrays(np.ndarray input not None, np.ndarray output not None):
     cdef np.uint8_t[:] ibuf

libdebugger/libdebugger.c

@@ -267,7 +267,13 @@ int libdebugger_calc_frame(emu_frame_callback_ptr calc, uint8_t *memory, frame_s
 		default:
 		output->frame_number += 1;
 		output->current_instruction_in_frame = 0;
-		output->current_cycle_in_frame = 0;
+
+		// number of cycles may cross a frame boundary, so any extra cycles
+		// recorded in the last frame are skipped at the start of this frame
+		output->current_cycle_in_frame -= output->final_cycle_in_frame;
+		if (output->current_cycle_in_frame < 0) {
+			printf("warning: frame %d starting at negative cycle offset %d\n", output->frame_number, output->current_cycle_in_frame);
+		}
 		libdebugger_memory_access_start_frame(memory, output);
 	}
 	output->frame_status = FRAME_INCOMPLETE;

libudis/libudis.h

@@ -44,8 +44,8 @@ typedef struct {
 	uint8_t after2;
 	uint8_t before3;
 	uint8_t after3;
-	uint8_t extra1;
-	uint8_t extra2;
+	uint8_t clock_cycle_in_scan_line;
+	uint8_t scan_line;
 } history_6502_t; /* 24 bytes */
 
 typedef struct {

omnivore/disassembler/dtypes.py

@@ -31,8 +31,8 @@
     ("after2", np.uint8),
     ("before3", np.uint8),
     ("after3", np.uint8),
-    ("extra1", np.uint8),
-    ("extra2", np.uint8),
+    ("cycle_in_scan_line", np.uint8),
+    ("scan_line", np.uint8),
 ])
 
 HISTORY_ATARI800_DTYPE = np.dtype([

omnivore/viewers/history.py

@@ -61,7 +61,10 @@ def get_row_label_text(self, start_line, num_lines, step=1):
             if t == flags.DISASM_NEXT_INSTRUCTION:
                 h = h.view(dtype=dd.HISTORY_BREAKPOINT_DTYPE)
                 t = h['disassembler_type_cpu']
-            if t == flags.DISASM_ATARI800_HISTORY:
+            if t == flags.DISASM_ATARI800_HISTORY or t == flags.DISASM_6502_HISTORY:
+                # lib6502 uses same cycles/scanline info in history, named
+                # differently but having same meaning as antic_xpos and
+                # antic_ypos
                 h = h.view(dtype=dd.HISTORY_ATARI800_DTYPE)
                 x = h['antic_xpos']
                 y = h['antic_ypos']