cli/CMakeLists.txt

@@ -20,7 +20,6 @@ add_executable(gb6
     ../src/instructions.c
     ../src/lcd.c
     ../src/rom.c
-    ../src/mbc.c
     emulator.c
     lcd_imgui.c
     imgui/imgui_demo.cpp

cli/imgui_example.cpp

@@ -13,7 +13,6 @@ extern "C" {
 #include "cpu.h"
 #include "rom.h"
 #include "lcd.h"
-#include "instructions.h"
 }
 
 static const char *A_FORMAT = "A: 0x%02x";
@@ -25,10 +24,8 @@ static const char *H_FORMAT = "H: 0x%02x";
 static const char *L_FORMAT = "L: 0x%02x";
 static const char *SP_FORMAT = "SP: 0x%02x";
 static const char *PC_FORMAT = "PC: 0x%02x";
-static const char *INSN_FORMAT = "Next instruction: %s";
 
 unsigned char output_image[256 * 256 * 4];
-unsigned char visible_pixels[160 * 144 * 4];
 unsigned char vram_tiles[256 * 96 * 4];
 
 struct key_input {
@@ -62,7 +59,7 @@ GLuint make_output_texture() {
     return image_texture;
 }
 
-unsigned char default_palette[] = { 0xff, 0xaa, 0x55, 0x00 };
+unsigned char default_palette[] = { 0, 0x55, 0xaa, 0xff };
 
 void convert_output(struct lcd *lcd) {
     int x, y;
@@ -78,17 +75,6 @@ void convert_output(struct lcd *lcd) {
             output_image[out_index++] = 255;
         }
     }
-    out_index = 0;
-    for (y = 0; y < 144; y++) {
-        for (x = 0; x < 160; x++) {
-            int val = lcd->pixels[y * 160 + x];
-            int fill = default_palette[val];
-            visible_pixels[out_index++] = fill;
-            visible_pixels[out_index++] = fill;
-            visible_pixels[out_index++] = fill;
-            visible_pixels[out_index++] = 255;
-        }
-    }
 }
 
 void convert_vram(struct dmg *dmg) {
@@ -208,7 +194,6 @@ int main(int argc, char *argv[])
 
     // setup output
     GLuint texture = make_output_texture();
-    GLuint vis_texture = make_output_texture();
     GLuint vram_texture = make_output_texture();
 
     editor.ReadFn = read_mem;
@@ -291,9 +276,6 @@ int main(int argc, char *argv[])
                 ImGui::SameLine();
                 ImGui::Text(PC_FORMAT, dmg.cpu->pc);
 
-                u8 opc = dmg_read(&dmg, dmg.cpu->pc);
-                ImGui::Text(INSN_FORMAT, instructions[opc].format);
-
                 ImGui::Checkbox("Z", &z_flag);
                 ImGui::SameLine();
                 ImGui::Checkbox("N", &n_flag);
@@ -320,10 +302,10 @@ int main(int argc, char *argv[])
                 ImGui::End();
             }
 
-            convert_output(dmg.lcd);
             {
                 ImGui::Begin("Output");
 
+                convert_output(dmg.lcd);
                 glBindTexture(GL_TEXTURE_2D, texture);
                 glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 256, 256, 0, GL_RGBA, GL_UNSIGNED_BYTE, output_image);
                 ImGui::Image((void*)(intptr_t) texture, ImVec2(512, 512));
@@ -331,16 +313,6 @@ int main(int argc, char *argv[])
                 ImGui::End();
             }
 
-            {
-                ImGui::Begin("LCD");
-
-                glBindTexture(GL_TEXTURE_2D, vis_texture);
-                glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 160, 144, 0, GL_RGBA, GL_UNSIGNED_BYTE, visible_pixels);
-                ImGui::Image((void*)(intptr_t) vis_texture, ImVec2(320, 288));
-
-                ImGui::End();
-            }
-
             {
                 ImGui::Begin("VRAM");
 

src/cpu.c

@@ -213,7 +213,7 @@ static u8 srl(struct cpu *cpu, u8 value)
     }
     clear_flag(cpu, FLAG_SIGN);
     clear_flag(cpu, FLAG_HALF_CARRY);
-    return result;
+    return 0;
 }
 
 static u8 swap(struct cpu *cpu, u8 value)
@@ -269,8 +269,7 @@ static void add(struct cpu *cpu, u8 value, int with_carry)
 {
     u8 sum_trunc;
     int sum_full = cpu->a + value;
-    int carry = (with_carry && flag_isset(cpu, FLAG_CARRY)) ? 1 : 0;
+    if (with_carry && flag_isset(cpu, FLAG_CARRY)) {
-    if (carry) {
         sum_full++;
     }
     sum_trunc = (u8) sum_full;
@@ -280,12 +279,12 @@ static void add(struct cpu *cpu, u8 value, int with_carry)
         clear_flag(cpu, FLAG_ZERO);
     }
     clear_flag(cpu, FLAG_SIGN);
-    if (sum_full > 0xff) {
+    if (sum_full > sum_trunc) {
         set_flag(cpu, FLAG_CARRY);
     } else {
         clear_flag(cpu, FLAG_CARRY);
     }
-    if (((cpu->a & 0xf) + (value & 0xf) + carry) & 0x10) {
+    if (((cpu->a & 0xf) + (value & 0xf)) & 0x10) {
         set_flag(cpu, FLAG_HALF_CARRY);
     } else {
         clear_flag(cpu, FLAG_HALF_CARRY);
@@ -297,11 +296,10 @@ static void subtract(struct cpu *cpu, u8 value, int with_carry, int just_compare
 {
     u8 sum_trunc;
     int sum_full = cpu->a - value;
-    int carry = (with_carry && flag_isset(cpu, FLAG_CARRY)) ? 1 : 0;
+    if (with_carry && flag_isset(cpu, FLAG_CARRY)) {
-    if (carry) {
         sum_full--;
     }
-    sum_trunc = (u8) sum_full;
+    sum_trunc = (u8) (sum_full & 0xff);
     if (!sum_trunc) {
         set_flag(cpu, FLAG_ZERO);
     } else {
@@ -455,34 +453,6 @@ static void conditional_jump(struct cpu *cpu, u8 opc, u8 neg_op, int flag) {
     }
 }
 
-static void daa(struct cpu *cpu)
-{
-    // https://forums.nesdev.org/viewtopic.php?t=15944
-    if (!flag_isset(cpu, FLAG_SIGN)) {
-        if (flag_isset(cpu, FLAG_CARRY) || cpu->a > 0x99) {
-            cpu->a += 0x60;
-            set_flag(cpu, FLAG_CARRY);
-        }
-        if (flag_isset(cpu, FLAG_HALF_CARRY) || (cpu->a & 0x0f) > 0x09) {
-            cpu->a += 0x6;
-        }
-    } else {
-        if (flag_isset(cpu, FLAG_CARRY)) {
-            cpu->a -= 0x60;
-        }
-        if (flag_isset(cpu, FLAG_HALF_CARRY)) {
-            cpu->a -= 0x6;
-        }
-    }
-
-    if (cpu->a) {
-        set_flag(cpu, FLAG_ZERO);
-    } else {
-        clear_flag(cpu, FLAG_ZERO);
-    }
-    clear_flag(cpu, FLAG_HALF_CARRY);
-}
-
 static u16 handlers[] = { 0x40, 0x48, 0x50, 0x58, 0x60 };
 
 static u16 check_interrupts(struct cpu *cpu)
@@ -542,9 +512,6 @@ void cpu_step(struct cpu *cpu)
         case 0x0f: // RRCA
             cpu->a = rrc(cpu, cpu->a);
             break;
-        case 0x10: // STOP
-            cpu->pc++;
-            break;
         case 0x11: // LD DE,d16
             write_de(cpu, read16(cpu, cpu->pc));
             cpu->pc += 2;
@@ -569,13 +536,6 @@ void cpu_step(struct cpu *cpu)
             cpu->a = rotate_right(cpu, cpu->a);
             break;
 
-        case 0x37: // SCF
-            set_flag(cpu, FLAG_CARRY);
-            break;
-        case 0x3f: // CCF
-            clear_flag(cpu, FLAG_CARRY);
-            break;
-
         // incs and decs
         case 0x03: write_bc(cpu, read_bc(cpu) + 1); break;
         case 0x04: inc_with_carry(cpu, &cpu->b); break;
@@ -801,7 +761,7 @@ void cpu_step(struct cpu *cpu)
         case 0xd2: // JP NC,a16
             temp16 = read16(cpu, cpu->pc);
             cpu->pc += 2;
-            if (!flag_isset(cpu, FLAG_CARRY)) {
+            if (flag_isset(cpu, FLAG_CARRY)) {
                 cpu->pc = temp16;
                 cpu->cycle_count += instructions[opc].cycles_branch - instructions[opc].cycles;
             }
@@ -812,14 +772,6 @@ void cpu_step(struct cpu *cpu)
                 cpu->cycle_count += instructions[opc].cycles_branch - instructions[opc].cycles;
             }
             break;
-        case 0xda: // JP C, u16
-            temp16 = read16(cpu, cpu->pc);
-            cpu->pc += 2;
-            if (flag_isset(cpu, FLAG_CARRY)) {
-                cpu->pc = temp16;
-                cpu->cycle_count += instructions[opc].cycles_branch - instructions[opc].cycles;
-            }
-            break;
 
         case 0x80: add(cpu, cpu->b, 0); break;
         case 0x81: add(cpu, cpu->c, 0); break;
@@ -870,7 +822,7 @@ void cpu_step(struct cpu *cpu)
             break;
 
         case 0xde: // SBC A, u8
-            subtract(cpu, read8(cpu, cpu->pc), 1, 0);
+            subtract(cpu, read8(cpu, cpu->pc), 0, 1);
             cpu->pc++;
             break;
 
@@ -932,7 +884,6 @@ void cpu_step(struct cpu *cpu)
         case 0xff: push(cpu, cpu->pc); cpu->pc = 0x38; break;
 
         case 0x27: // DAA
-            daa(cpu);
             break;
 
         case 0x76: // HALT
@@ -998,7 +949,6 @@ void cpu_step(struct cpu *cpu)
             break;
         case 0xf1: // POP AF
             write_af(cpu, pop(cpu));
-            cpu->f &= 0xf0;
             break;
         case 0xf2: // LD A,(C)
             cpu->a = read8(cpu, 0xff00 + cpu->c);

src/dmg.c

@@ -5,7 +5,6 @@
 #include "rom.h"
 #include "lcd.h"
 #include "dmg.h"
-#include "mbc.h"
 #include "types.h"
 #include "bootstrap.h"
 
@@ -55,24 +54,19 @@ static int counter;
 u8 dmg_read(void *_dmg, u16 address)
 {
     struct dmg *dmg = (struct dmg *) _dmg;
-    u8 mbc_data;
-
-    if (mbc_read(dmg->rom->mbc, dmg, address, &mbc_data)) {
-        return mbc_data;
-    }
-
 //    if (address < 0x100) {
 //        return dmg_boot_rom[address];
 //    } else if (address < 0x4000) {
     if (address < 0x4000) {
         return dmg->rom->data[address];
     } else if (address < 0x8000) {
+        // TODO switchable rom bank
         return dmg->rom->data[address];
     } else if (address < 0xa000) {
         return dmg->video_ram[address - 0x8000];
     } else if (address < 0xc000) {
-        printf("RAM bank not handled by MBC\n");
+        // TODO switchable ram bank
-        return 0xff;
+        return 0;
     } else if (address < 0xe000) {
         return dmg->main_ram[address - 0xc000];
     } else if (lcd_is_valid_addr(address)) {
@@ -99,16 +93,13 @@ u8 dmg_read(void *_dmg, u16 address)
 void dmg_write(void *_dmg, u16 address, u8 data)
 {
     struct dmg *dmg = (struct dmg *) _dmg;
-
-    if (mbc_write(dmg->rom->mbc, dmg, address, data)) {
-        return;
-    }
-
     if (address < 0x4000) {
         printf("warning: writing 0x%04x in rom\n", address);
+        dmg->rom->data[address] = data;
     } else if (address < 0x8000) {
         // TODO switchable rom bank
         printf("warning: writing 0x%04x in rom\n", address);
+        dmg->rom->data[address] = data;
     } else if (address < 0xa000) {
         dmg->video_ram[address - 0x8000] = data;
     } else if (address < 0xc000) {
@@ -144,86 +135,6 @@ void dmg_request_interrupt(struct dmg *dmg, int nr)
     dmg->interrupt_requested |= nr;
 }
 
-// TODO move to lcd.c, it needs to be able to access dmg_read though
-static void render_background(struct dmg *dmg, int lcdc)
-{
-    int bg_base = (lcdc & LCDC_BG_TILE_MAP) ? 0x9c00 : 0x9800;
-    int window_base = (lcdc & LCDC_WINDOW_TILE_MAP) ? 0x9c00 : 0x9800;
-    int use_unsigned = lcdc & LCDC_BG_TILE_DATA;
-    int tilebase = use_unsigned ? 0x8000 : 0x9000;
-
-    //printf("%04x %04x %04x\n", bg_base, window_base, tilebase);
-
-    int k = 0, off = 0;
-    int tile_y = 0, tile_x = 0;
-    for (tile_y = 0; tile_y < 32; tile_y++) {
-        for (tile_x = 0; tile_x < 32; tile_x++) {
-            off = 256 * 8 * tile_y + 8 * tile_x;
-            int tile = dmg_read(dmg, bg_base + (tile_y * 32 + tile_x));
-            int eff_addr;
-            if (use_unsigned) {
-                eff_addr = tilebase + 16 * tile;
-            } else {
-                eff_addr = tilebase + 16 * (signed char) tile;
-            }
-            int b, i;
-            for (b = 0; b < 16; b += 2) {
-                int data1 = dmg_read(dmg, eff_addr + b);
-                int data2 = dmg_read(dmg, eff_addr + b + 1);
-                for (i = 7; i >= 0; i--) {
-                    dmg->lcd->buf[off] = ((data1 & (1 << i)) ? 1 : 0) << 1;
-                    dmg->lcd->buf[off] |= (data2 & (1 << i)) ? 1 : 0;
-                    off++;
-                }
-                off += 248;
-            }
-        }
-    }
-}
-
-struct oam_entry {
-    u8 pos_y;
-    u8 pos_x;
-    u8 tile;
-    u8 attrs;
-};
-
-// TODO: only ten per scanline, priority
-static void render_objs(struct dmg *dmg)
-{
-    struct oam_entry *oam = (struct oam_entry *) dmg->lcd->oam;
-    int k, lcd_x, lcd_y, off;
-    for (k = 0; k < 40; k++, oam++) {
-        if (oam->pos_y == 0 || oam->pos_y >= 160) {
-            continue;
-        }
-        if (oam->pos_x == 0 || oam->pos_y >= 168) {
-            continue;
-        }
-
-        lcd_x = oam->pos_x - 8;
-        lcd_y = oam->pos_y - 16;
-
-        off = 160 * lcd_y + lcd_x;
-        int eff_addr = 0x8000 + 16 * oam->tile;
-        int b, i;
-        for (b = 0; b < 16; b += 2) {
-            int data1 = dmg_read(dmg, eff_addr + b);
-            int data2 = dmg_read(dmg, eff_addr + b + 1);
-            for (i = 7; i >= 0; i--) {
-                if (off < 0 || off >= 160 * 144) {
-                    // terrible clipping. need to not have an if per-pixel
-                    continue;
-                }
-                dmg->lcd->pixels[off] = ((data1 & (1 << i)) ? 1 : 0) << 1;
-                dmg->lcd->pixels[off] |= (data2 & (1 << i)) ? 1 : 0;
-                off++;
-            }
-            off += 152;
-        }
-    }
-}
-
 void dmg_step(void *_dmg)
 {
     struct dmg *dmg = (struct dmg *) _dmg;
@@ -254,7 +165,6 @@ void dmg_step(void *_dmg)
             lcd_set_mode(dmg->lcd, 1);
         }
 
-        // TODO: do all of this per-scanline instead of everything in vblank
         if (next_scanline == 144) {
             // vblank has started, draw all the stuff from ram into the lcd
             dmg_request_interrupt(dmg, INT_VBLANK);
@@ -263,20 +173,41 @@ void dmg_step(void *_dmg)
             }
 
             int lcdc = lcd_read(dmg->lcd, REG_LCDC);
-            if (lcdc & LCDC_ENABLE_BG) {
+            int bg_base = (lcdc & LCDC_BG_TILE_MAP) ? 0x9c00 : 0x9800;
-                render_background(dmg, lcdc);
+            int window_base = (lcdc & LCDC_WINDOW_TILE_MAP) ? 0x9c00 : 0x9800;
-            }
+            int use_unsigned = lcdc & LCDC_BG_TILE_DATA;
-
+            int tilebase = use_unsigned ? 0x8000 : 0x9000;
-            if (lcdc & LCDC_ENABLE_WINDOW) {
+
-                // printf("window\n");
+            //printf("%04x %04x %04x\n", bg_base, window_base, tilebase);
-            }
+
-
+            int k = 0, off = 0;
-            lcd_apply_scroll(dmg->lcd);
+            int tile_y = 0, tile_x = 0;
-
+            for (tile_y = 0; tile_y < 32; tile_y++) {
-            if (lcdc & LCDC_ENABLE_OBJ) {
+                for (tile_x = 0; tile_x < 32; tile_x++) {
-                render_objs(dmg);
+                    off = 256 * 8 * tile_y + 8 * tile_x;
+                    int tile = dmg_read(dmg, bg_base + (tile_y * 32 + tile_x));
+                    int eff_addr;
+                    if (use_unsigned) {
+                        eff_addr = tilebase + 16 * tile;
+                    } else {
+                        eff_addr = tilebase + 16 * (signed char) tile;
+                    }
+                    int b, i;
+                    for (b = 0; b < 16; b += 2) {
+                        int data1 = dmg_read(dmg, eff_addr + b);
+                        int data2 = dmg_read(dmg, eff_addr + b + 1);
+                        for (i = 7; i >= 0; i--) {
+                            dmg->lcd->buf[off] = ((data1 & (1 << i)) ? 1 : 0) << 1;
+                            dmg->lcd->buf[off] |= (data2 & (1 << i)) ? 1 : 0;
+                            off++;
+                        }
+                        off += 248;
+                    }
+                }
             }
 
+            // now copy 256x256 buf to 160x144 based on window registers
+            lcd_copy(dmg->lcd);
             lcd_draw(dmg->lcd);
         }
     } else {

src/dmg.h

@@ -1,7 +1,9 @@
 #ifndef _DMG_H
 #define _DMG_H
 
-#include "types.h"
+#include "cpu.h"
+#include "rom.h"
+#include "lcd.h"
 
 #define FIELD_JOY 1
 #define FIELD_ACTION 2
@@ -15,10 +17,6 @@
 #define BUTTON_SELECT (1 << 2)
 #define BUTTON_START (1 << 3)
 
-struct cpu;
-struct rom;
-struct lcd;
-
 struct dmg {
     struct cpu *cpu;
     struct rom *rom;

src/lcd.c

@@ -66,20 +66,10 @@ void lcd_put_pixel(struct lcd *lcd, u8 x, u8 y, u8 value)
     lcd->pixels[y * LCD_WIDTH + x] = value;
 }
 
-void lcd_apply_scroll(struct lcd *lcd)
+void lcd_copy(struct lcd *lcd)
 {
-    int scroll_y = lcd_read(lcd, REG_SCY);
+    // use all the registers to compute the pixel data
-    int scroll_x = lcd_read(lcd, REG_SCX);
+    
-
-    int lines;
-    for (lines = 0; lines < 144; lines++) {
-        int src_y = (scroll_y + lines) & 0xff;
-        int cols;
-        for (cols = 0; cols < 160; cols++) {
-            int src_off = (src_y << 8) + ((scroll_x + cols) & 0xff);
-            lcd->pixels[lines * 160 + cols] = lcd->buf[src_off];
-        }
-    }
 }
 
 int lcd_step(struct lcd *lcd)

src/lcd.h

@@ -58,8 +58,9 @@ void lcd_clear_bit(struct lcd *lcd, u16 addr, u8 bit);
 int lcd_isset(struct lcd *lcd, u16 addr, u8 bit);
 void lcd_set_mode(struct lcd *lcd, int mode);
 
+// i feel like i'm going to need to call this every cycle and update regs
 int lcd_step(struct lcd *lcd);
-void lcd_apply_scroll(struct lcd *lcd);
+void lcd_copy(struct lcd *lcd);
 
 // output the pixels to the screen
 void lcd_draw(struct lcd *lcd);

src/mbc.c

@@ -1,94 +0,0 @@
-#include <stdlib.h>
-#include <stdio.h>
-
-#include "types.h"
-#include "mbc.h"
-#include "dmg.h"
-#include "rom.h"
-
-static int mbc_noop_read(struct mbc *mbc, struct dmg *dmg, u16 addr, u8 *out_data)
-{
-  return 0;
-}
-
-static int mbc_noop_write(struct mbc *mbc, struct dmg *dmg, u16 addr, u8 data)
-{
-  return 0;
-}
-
-static int mbc1_read(struct mbc *mbc, struct dmg *dmg, u16 addr, u8 *out_data)
-{
-  if (addr >= 0x4000 && addr <= 0x7fff) {
-    int use_bank = mbc->rom_bank;
-    if (!use_bank) {
-      use_bank = 1;
-    }
-    *out_data = dmg->rom->data[0x4000 * use_bank + (addr & 0x3fff)];
-    return 1;
-  } else if (addr >= 0xa000 && addr <= 0xbfff) {
-    if (mbc->ram_enabled) {
-      *out_data = mbc->ram[0x2000 * mbc->ram_bank + (addr & 0x1fff)];
-    } else {
-      *out_data = 0xff;
-    }
-    return 1;
-  }
-
-  return 0;
-}
-
-static int mbc1_write(struct mbc *mbc, struct dmg *dmg, u16 addr, u8 data)
-{
-  if (addr >= 0 && addr <= 0x1fff) {
-    mbc->ram_enabled = (data & 0xf) == 0xa;
-    return 1;
-  } else if (addr >= 0x2000 && addr <= 0x3fff) {
-    mbc->rom_bank = data & 0x1f;
-    return 1;
-  } else if (addr >= 0x4000 && addr <= 0x5fff) {
-    mbc->ram_bank = data & 0x03;
-    return 1;
-  } else if (addr >= 0x6000 && addr <= 0x7fff) {
-    //printf("sel %d\n", data);
-    return 1;
-  } else if (addr >= 0xa000 && addr <= 0xbfff) {
-    if (mbc->ram_enabled) {
-      mbc->ram[0x2000 * mbc->ram_bank + (addr & 0x1fff)] = data;
-      return 1;
-    }
-  }
-  return 0;
-}
-
-struct mbc mbc_noop = {
-  mbc_noop_read,
-  mbc_noop_write,
-};
-
-struct mbc mbc1 = {
-  mbc1_read,
-  mbc1_write,
-};
-
-struct mbc *mbc_new(int type)
-{
-  switch (type) {
-    case 0:
-      return &mbc_noop;
-    case 1:
-    case 2:
-    case 3:
-      return &mbc1;
-  }
-  return NULL;
-}
-
-int mbc_read(struct mbc *mbc, struct dmg *dmg, u16 addr, u8 *out_data)
-{
-  return mbc->read_fn(mbc, dmg, addr, out_data);
-}
-
-int mbc_write(struct mbc *mbc, struct dmg *dmg, u16 addr, u8 data)
-{
-  return mbc->write_fn(mbc, dmg, addr, data);
-}

src/mbc.h

@@ -1,22 +0,0 @@
-#ifndef _MBC_H
-#define _MBC_H
-
-#include "types.h"
-
-struct dmg;
-
-struct mbc {
-  int (*read_fn)(struct mbc *, struct dmg *, u16, u8 *);
-  int (*write_fn)(struct mbc *, struct dmg *, u16, u8);
-  int type;
-  int rom_bank;
-  int ram_bank;
-  int ram_enabled;
-  u8 ram[0x8000];
-};
-
-struct mbc *mbc_new(int type);
-int mbc_read(struct mbc *mbc, struct dmg *dmg, u16 addr, u8 *out_data);
-int mbc_write(struct mbc *mbc, struct dmg *dmg, u16 addr, u8 data);
-
-#endif

src/rom.c

@@ -17,15 +17,12 @@ int rom_load(struct rom *rom, const char *filename)
     len = ftell(fp);
     rewind(fp);
 
+    rom->type = 0; // TODO read type from cart
     rom->data = malloc(len);
     rom->length = len;
     if (fread(rom->data, 1, len, fp) < len) {
         return 0;
     }
-    rom->mbc = mbc_new(rom->data[0x147]);
-    if (!rom->mbc) {
-        return 0;
-    }
 
     return 1;
 }

src/rom.h

@@ -2,12 +2,11 @@
 #define _ROM_H
 
 #include "types.h"
-#include "mbc.h"
 
 struct rom {
     u32 length;
+    int type;
     u8 *data;
-    struct mbc *mbc;
 };
 
 int rom_load(struct rom *rom, const char *filename);

system6/CMakeLists.txt

@@ -12,7 +12,6 @@ add_application(Emulator
     ../src/instructions.c
     ../src/lcd.c
     ../src/rom.c
-    ../src/mbc.c
     emulator.c
     lcd_mac.c
     resources.r

system6/emulator.c

@@ -18,7 +18,6 @@
 #include "cpu.h"
 #include "rom.h"
 #include "lcd.h"
-#include "mbc.h"
 
 WindowPtr g_wp;
 DialogPtr stateDialog;
@@ -53,9 +52,8 @@ void InitEverything(void)
   g_running = 1;
 }
 
-// 160 pixels / 8 bits per pixel = 20 bytes per line
+char offscreen[32 * 256];
-char offscreen[20 * 144];
+Rect offscreenRect = { 0, 0, 256, 256 };
-Rect offscreenRect = { 0, 0, 144, 160 };
 
 BitMap offscreenBmp;
 
@@ -63,34 +61,26 @@ int lastTicks;
 
 void Render(void)
 {
-  long k = 0, dst, bit;
+  long k = 0, dst;
-  for (dst = 0; dst < 20 * 144; dst++) {
+  for (dst = 0; dst < 32 * 256; dst++) {
-    for (bit = 7; bit >= 0; bit--) {
+    offscreen[dst] = lcd.buf[k++] << 7
-      offscreen[dst] |= lcd.pixels[k++];
+            | lcd.buf[k++] << 6
-      offscreen[dst] <<= 1;
+            | lcd.buf[k++] << 5
-    }
+            | lcd.buf[k++] << 4
-    dst++;
+            | lcd.buf[k++] << 3
+            | lcd.buf[k++] << 2
+            | lcd.buf[k++] << 1
+            | lcd.buf[k++];
   }
-
-  /*
-    offscreen[dst] = lcd.pixels[k++] << 7;
-    offscreen[dst] |= lcd.pixels[k++] << 6;
-    offscreen[dst] |= lcd.pixels[k++] << 5;
-    offscreen[dst] |= lcd.pixels[k++] << 4;
-    offscreen[dst] |= lcd.pixels[k++] << 3;
-    offscreen[dst] |= lcd.pixels[k++] << 2;
-    offscreen[dst] |= lcd.pixels[k++] << 1;
-    offscreen[dst] |= lcd.pixels[k++];
-  */
   SetPort(g_wp);
-  CopyBits(&offscreenBmp, &g_wp->portBits, &offscreenRect, &offscreenRect, srcCopy, NULL);
+  CopyBits(&offscreenBmp, &g_wp->portBits, &offscreenRect, &g_wp->portRect, srcCopy, NULL);
 
   //EraseRect(&g_wp->portRect);
-  // MoveTo(10, 160);
+  MoveTo(10, 160);
-  // char debug[128];
+  char debug[128];
-  // sprintf(debug, "PC: %04x", cpu.pc);
+  sprintf(debug, "PC: %04x", cpu.pc);
-  // C2PStr(debug);
+  C2PStr(debug);
-  // DrawString(debug);
+  DrawString(debug);
 }
 
 void StartEmulation(void)
@@ -101,7 +91,7 @@ void StartEmulation(void)
 
   offscreenBmp.baseAddr = offscreen;
   offscreenBmp.bounds = offscreenRect;
-  offscreenBmp.rowBytes = 20;
+  offscreenBmp.rowBytes = 32;
   emulationOn = 1;
 }
 
@@ -131,15 +121,8 @@ bool LoadRom(StrFileName fileName, short vRefNum)
   }
   
   amtRead = rom.length;
+  
   FSRead(fileNo, &amtRead, rom.data);
-
-  rom.mbc = mbc_new(rom.data[0x147]);
-  if (!rom.mbc) {
-    ParamText("\pThis cartridge type is unsupported.", "\p", "\p", "\p");
-    Alert(ALRT_4_LINE, NULL);
-    return false;
-  }
-
   return true;
 }
 
@@ -282,25 +265,24 @@ int main(int argc, char *argv[])
           lastTicks = now;
           Render();
         }
-      if (Button()) g_running = false;
+    }
-    } else {
+
-      if(WaitNextEvent(everyEvent, &evt, 0, 0) != nullEvent) {
+    if(WaitNextEvent(everyEvent, &evt, 0, 0) != nullEvent) {
-        if (IsDialogEvent(&evt)) {
+      if (IsDialogEvent(&evt)) {
-          DialogRef hitBox;
+        DialogRef hitBox;
-          DialogItemIndex hitItem;
+        DialogItemIndex hitItem;
-          if (DialogSelect(&evt, &hitBox, &hitItem)) {
+        if (DialogSelect(&evt, &hitBox, &hitItem)) {
-            stateDialog = NULL;
+          stateDialog = NULL;
-          }
-        } else switch(evt.what) {
-          case mouseDown:
-            OnMouseDown(&evt);
-            break;
-          case updateEvt:
-            BeginUpdate((WindowPtr) evt.message);
-            Render();
-            EndUpdate((WindowPtr) evt.message);
-            break;
         }
+      } else switch(evt.what) {
+        case mouseDown:
+          OnMouseDown(&evt);
+          break;
+        case updateEvt:
+          BeginUpdate((WindowPtr) evt.message);
+          Render();
+          EndUpdate((WindowPtr) evt.message);
+          break;
       }
     }
   }

system6/emulator.h

@@ -7,7 +7,7 @@
 #include "types.h"
 #include "dmg.h"
 
-#define WINDOW_TITLE "\pOutput"
+#define WINDOW_TITLE "\pEmulator"
 
 #define WINDOW_X 100
 #define WINDOW_Y 100