//
// Stargate Emulator (StarGem2) v2.0 SDL
//
-// by James L. Hammons
-// (C) 2006 Underground Software
+// by James Hammons
+// (C) 2006, 2023 Underground Software
//
-// JLH = James L. Hammons <jlhamm@acm.org>
+// JLH = James Hammons <jlhamm@acm.org>
//
// WHO WHEN WHAT
// --- ---------- ------------------------------------------------------------
// JLH 06/15/2006 Added changelog ;-)
// JLH 06/15/2006 Switched over to timeslice execution code
+// JLH 07/15/2009 Solved problem with DEMO mode (IRQ handling) (No, didn't)
+// JLH 01/03/2023 FINALLY solved problem with DEMO mode (v6809 timing)
//
-#include "SDL.h"
+#include <SDL2/SDL.h>
#include <fstream>
#include <string>
#include <iomanip>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
-#include "types.h"
+#include <stdint.h>
+#include "dis6808.h"
+#include "dis6809.h"
#include "log.h"
+#include "settings.h"
+#include "sound.h"
+#include "timing.h"
#include "v6808.h"
#include "v6809.h"
+#include "v6821.h"
#include "video.h"
-#include "sound.h"
-#include "timing.h"
-#include "settings.h"
-#include "dis6809.h"
-#include "dis6808.h"
-
-#define __DEBUG__
using namespace std;
#define CMOS "cmos.ram"
#define SAVESTATE "sg2.state"
-// Global variables
-
-uint8 gram[0x10000], grom[0x10000], sram[0x10000], srom[0x10000]; // RAM & ROM spaces
-V6809REGS mainCPU;
-V6808REGS soundCPU;
-uint8 color[16];
-uint32 palette[256];
+#define FRAME_DURATION_IN_CYCLES (M6809_CLOCK_SPEED_IN_HZ / 60.0)
+#define SCANLINE_DURATION_IN_CYCLES (FRAME_DURATION_IN_CYCLES / 256.0)
+#define SG2_PIA_CALLBACK_DURATION (SCANLINE_DURATION_IN_CYCLES * M6809_CYCLE_IN_USEC * 16.0)
-// Local variables
+// Function prototypes
-static bool running = true; // Machine running state flag...
-static uint32 startTicks;
-static uint8 * keys; // SDL raw keyboard matrix
+uint8_t RdMem6809(uint16_t addr);
+void WrMem6809(uint16_t addr, uint8_t b);
+void Handle6809IRQ(bool);
+uint8_t RdMem6808(uint16_t addr);
+void WrMem6808(uint16_t addr, uint8_t b);
+bool LoadImg(const char * filename, uint8_t * ram, int size);
+void SaveCMOS(void);
+bool LoadMachineState(void);
+void SaveMachineState(void);
// Local timer callback functions
static void FrameCallback(void);
static void ScanlineCallback(void);
+// Global variables
-//
-// 6809 memory functions
-//
-
-uint8 RdMem6809(uint16 addr)
-{
- uint8 b;
-
- if (addr >= 0x9000 && addr <= 0xCFFF) // No ROM between $9000 - $CFFF...
- b = gram[addr];
- else
- {
- if (!gram[0xC900] && addr <= 0x8FFF) // Check RAM $C900 bank switch
- b = gram[addr];
- else
- b = grom[addr];
- }
-
-//Is $C80E COUNT240? Hmm... No.
-
-//temp...
-/*extern uint16 pcr;
-//if (addr >= 0xC000 && addr <= 0xCBFF)
-if (addr == 0x9C59)
- WriteLog("RdMem: Reading address %04X [=%02X, PC=%04X]\n", addr, b, pcr);//*/
-/*if (addr >= 0xC80D && addr <= 0xC80F)
- WriteLog("V6809 RdMem: Reading address %04X [=%02X, PC=%04X]\n", addr, b, mainCPU.pc);//*/
-
- return b;
-}
-
-void WrMem6809(uint16 addr, uint8 b)
-{
-//temp...
-//extern V6809REGS regs;
-//if (addr >= 0xC800 && addr <= 0xCBFE)
-//if (addr == 0xC80F || addr == 0xC80D)
-// WriteLog("WrMem: Writing address %04X with %02X [PC=%04X, $CB00=%02X]\n", addr, b, regs.pc, gram[0xCB00]);//*/
-//if (addr == 0xC80E)
-/*if (addr >= 0xC800 && addr <= 0xC80F)
- WriteLog("V6809 WrMem: Writing address %04X with %02X [PC=%04X, $CB00=%02X]\n", addr, b, mainCPU.pc, gram[0xCB00]);//*/
-
- gram[addr] = b;
-
- if (addr > 0x0006 && addr < 0x97F7) // 304 pixels 152-128=24-16=8
- {
- // NOTE: Screen was 304 x 256, but we truncate the vertical dimension here...
- uint16 sx = (addr >> 7) & 0x01FE, sy = addr & 0x00FF;
-
- if (sy > 5 && sy < 246)
- {
- uint32 saddr = 8 + sx + ((sy - 6) * 320); // Calc screen address
-//Hmm. This approach won't work with palette color cycling...
-#if 0
- scrBuffer[saddr + 0] = b >> 4;
- scrBuffer[saddr + 1] = b & 0x0F;
-#else
- scrBuffer[saddr + 0] = palette[color[b >> 4]];
- scrBuffer[saddr + 1] = palette[color[b & 0x0F]];
-#endif
- }
- }
- else if (addr >= 0xC000 && addr <= 0xC00F)
-//Let's see if we can fix the color cycling here... [DONE]
-#if 0
- color[addr - 0xC000] = b; // color[] from VIDEO.CPP (not any more!)
-#else
- {
-// A better strategy here would probably be to set a flag when the color register changes,
-// then change it before doing the render.
-// ALSO: This approach doesn't take the color to the edges of the screen
- color[addr - 0xC000] = b;
-
- for(uint32 addr=0x0007; addr<0x97F7; addr++)
- {
- uint16 sx = (addr >> 7) & 0x01FE, sy = addr & 0x00FF;
-
- if (sy > 5 && sy < 246)
- {
- uint32 saddr = 8 + sx + ((sy - 6) * 320); // Calc screen address
- uint8 sb = gram[addr];
-
- scrBuffer[saddr + 0] = palette[color[sb >> 4]];
- scrBuffer[saddr + 1] = palette[color[sb & 0x0F]];
- }
- }
- }
-#endif
- else if (addr == 0xC80E)
- {
- sram[0x0402] = b; // Connect PIAs in 6809 & 6808
- soundCPU.cpuFlags |= V6808_ASSERT_LINE_IRQ; // Start sound IRQ
- }
-}
-
-//
-// 6808 memory functions
-//
-
-uint8 RdMem6808(uint16 addr)
-{
- return (addr < 0xF000 ? sram[addr] : srom[addr]);
-}
-
-void WrMem6808(uint16 addr, uint8 b)
-{
- sram[addr] = b;
-
- // A total guess, but let's try it...
-//It probably depends on how the PIA is configured, so this is most likely wrong.
-// if (addr == 0x0401)
-// soundCPU.cpuFlags &= ~V6808_ASSERT_LINE_IRQ;
-}
-
-//
-// Load a file into RAM/ROM image space
-//
-bool LoadImg(char * filename, uint8 * ram, int size)
-{
- FILE * fp = fopen(filename, "rb");
-
- if (fp == NULL)
- return false;
-
- fread(ram, 1, size, fp);
- fclose(fp);
-
- return true;
-}
-
-//
-// Save CMOS ram
-//
-void SaveCMOS(void)
-{
- FILE * fp = fopen(CMOS, "wb");
-
- if (fp != NULL)
- {
- fwrite(gram + 0xCC00, 1, 1024, fp);
- fclose(fp);
- }
- else
- WriteLog("CMOS RAM not saved!\n");
-}
-
-//
-// Load state save file
-//
-bool LoadMachineState(void)
-{
- FILE * fp = fopen(SAVESTATE, "rb");
-
- if (fp == NULL)
- return false;
-
- // This is kinda crappy--we don't do any sanity checking here!!!
- fread(gram, 1, 0x10000, fp);
- fread(sram, 1, 0x10000, fp);
- fread(&mainCPU, 1, sizeof(V6809REGS), fp);
- fread(&soundCPU, 1, sizeof(V6808REGS), fp);
- fclose(fp);
-
- for(int i=0x0006; i<0x97F8; i++) // Set up backbuffer... ;-)
- WrMem6809(i, gram[i]);
-
- mainCPU.RdMem = RdMem6809; // Make sure our function pointers are
- mainCPU.WrMem = WrMem6809; // pointing to the right places!
- soundCPU.RdMem = RdMem6808;
- soundCPU.WrMem = WrMem6808;
-
- return true;
-}
+uint8_t gram[0x10000], grom[0x10000], sram[0x10000], srom[0x10000]; // RAM & ROM spaces
+V6809REGS mainCPU;
+V6808REGS soundCPU;
+V6821PIA pia1;
+V6821PIA pia2(Handle6809IRQ, Handle6809IRQ);
+uint8_t color[16];
+uint32_t palette[256];
+bool paletteDirty = false;
-//
-// Save state save file
-//
-void SaveMachineState(void)
-{
- FILE * fp = fopen(SAVESTATE, "wb");
+// Local variables
- if (fp != NULL)
- {
- fwrite(gram, 1, 0x10000, fp);
- fwrite(sram, 1, 0x10000, fp);
- fwrite(&mainCPU, 1, sizeof(V6809REGS), fp);
- fwrite(&soundCPU, 1, sizeof(V6808REGS), fp);
- fclose(fp);
- }
- else
- WriteLog("Machine state not saved!\n");
-}
+static bool running = true; // Machine running state flag...
+static uint32_t startTicks;
+static const uint8_t * keys; // SDL raw keyboard matrix
+uint64_t clockFrameStart; // V6809 clock at the start of the frame
//
// Main loop
int main(int /*argc*/, char * /*argv*/[])
{
InitLog("stargem2.log");
- WriteLog("StarGem2 - A portable Stargate emulator by James L. Hammons\n");
+ WriteLog("StarGem2 - A portable Stargate emulator by James Hammons\n");
+ WriteLog("(C) 2023 Underground Software\n\n");
LoadSettings();
// Initialize Williams' palette (RGB coded as: 3 bits red, 3 bits green, 2 bits blue)
- for(uint32 i=0; i<256; i++)
+ for(uint32_t i=0; i<256; i++)
palette[i] =
#if SDL_BYTEORDER == SDL_BIG_ENDIAN
(((i & 0x01) * 33 + ((i & 0x02) >> 1) * 71 + ((i & 0x04) >> 2) * 151) << 24)
#endif
// Zero out memory
- for(long i=0; i<0x10000; i++)
- gram[i] = grom[i] = sram[i] = srom[i] = 0;
+ memset(gram, 0, 0x10000);
+ memset(grom, 0, 0x10000);
+ memset(sram, 0, 0x10000);
+ memset(srom, 0, 0x10000);
// Set up V6809 & V6808 execution contexts
-
- memset(&mainCPU, sizeof(V6809REGS), 0);
+
+ memset(&mainCPU, 0, sizeof(V6809REGS));
mainCPU.RdMem = RdMem6809;
mainCPU.WrMem = WrMem6809;
- mainCPU.cpuFlags |= V6809_ASSERT_LINE_RESET;
+ mainCPU.cpuFlags |= V6809_LINE_RESET;
- memset(&soundCPU, sizeof(V6808REGS), 0);
+ memset(&soundCPU, 0, sizeof(V6808REGS));
soundCPU.RdMem = RdMem6808;
soundCPU.WrMem = WrMem6808;
- soundCPU.cpuFlags |= V6808_ASSERT_LINE_RESET;
+ soundCPU.cpuFlags |= V6808_LINE_RESET;
char ROMs[12][8] = {
"ROMs/01", "ROMs/02", "ROMs/03", "ROMs/04", "ROMs/05", "ROMs/06",
"ROMs/07", "ROMs/08", "ROMs/09", "ROMs/10", "ROMs/11", "ROMs/12"
- };
+ };
for(int i=0; i<12; i++)
{
- uint32 baseAddress = i * 0x1000;
+ uint32_t baseAddress = i * 0x1000;
if (i > 8)
baseAddress += 0x4000;
-#if 0
-WriteLog("Loading ROM image '%s' at $%04X...\n", ROMs[i], baseAddress);
-#endif
-// if (!LoadImg(ROMs[i], grom + (i * 0x1000), 0x1000))
if (!LoadImg(ROMs[i], grom + baseAddress, 0x1000))
{
WriteLog("Could not open file '%s'!\n", ROMs[i]);
WriteLog("About to intialize audio...\n");
SoundInit();
-// uint8 * keys = SDL_GetKeyState(NULL);
- keys = SDL_GetKeyState(NULL);
-
-// running = true; // Set running status...
- srom[0xF800] = 0x37; // Fix checksum so ST works...
-
-#if 0
-
-//kludge...
-//This didn't work--it still acted like the old way (interrupt @ VC = 0)
-//gram[0xCB00] = 64*3;
-
- WriteLog("Entering main loop...\n");
- while (running)
- {
- SDL_PumpEvents(); // Force key events into the buffer.
- gram[0xC804] = gram[0xC806] = gram[0xC80C] = 0; // Reset PIA ports...
-
- if (keys[SDLK_ESCAPE])
- running = false; // ESC to exit...
-
- if (keys[SDLK_SEMICOLON])
- gram[0xC804] |= 0x01; // Fire (;)
- if (keys[SDLK_l])
- gram[0xC804] |= 0x02; // Thrust (L)
- if (keys[SDLK_SPACE])
- gram[0xC804] |= 0x04; // Smart Bomb (space)
- if (keys[SDLK_BACKSPACE])
- gram[0xC804] |= 0x08; // Hyperspace (BkSp)
- if (keys[SDLK_2])
- gram[0xC804] |= 0x10; // Two Player Start (2)
- if (keys[SDLK_1])
- gram[0xC804] |= 0x20; // One Player Start (1)
- if (keys[SDLK_RETURN])
- gram[0xC804] |= 0x40; // Reverse (Enter)
- if (keys[SDLK_f])
- gram[0xC804] |= 0x80; // Down (F)
-
- if (keys[SDLK_r])
- gram[0xC806] |= 0x01; // Up (R)
- if (keys[SDLK_a])
- gram[0xC806] |= 0x02; // Inviso (A)
-
- if (keys[SDLK_F1])
- gram[0xC80C] |= 0x01; // Auto up (F1)
- if (keys[SDLK_F2])
- gram[0xC80C] |= 0x02; // Advance (F2)
- if (keys[SDLK_5])
- gram[0xC80C] |= 0x04; // Right Coin (5)
- if (keys[SDLK_F3])
- gram[0xC80C] |= 0x08; // High Score Reset (F3)
- if (keys[SDLK_3])
- gram[0xC80C] |= 0x10; // Left Coin (3)
- if (keys[SDLK_4])
- gram[0xC80C] |= 0x20; // Center Coin (4)
- if (keys[SDLK_F4])
- gram[0xC80C] |= 0x40; // Slam Switch (F4)
-
- if (keys[SDLK_F5]) // Sound CPU self-test (F5)
- soundCPU.cpuFlags |= V6808_ASSERT_LINE_NMI;
- if (keys[SDLK_F6]) // Reset the 6808 (F6)
- soundCPU.cpuFlags |= V6808_ASSERT_LINE_RESET;
-
-/*
-$CB00 is scanline counter, bits 2-7 (1 frame/240 =69.44... usec)
-
-Some places of interest to look at:
-
-RdMem: Reading address C80E [=0C, PC=15C3] <- Inside interrupt (read, then discarded)...
-RdMem: Reading address CB00 [=43, PC=15C6] <- interrupt
-RdMem: Reading address C80C [=00, PC=0758] <- input (?)
-RdMem: Reading address C80C [=00, PC=07B9] <- input (?)
-RdMem: Reading address C806 [=00, PC=078C] <- input
-RdMem: Reading address C804 [=00, PC=2679] <- input
-*/
- uint32 startTicks = SDL_GetTicks();
-// long video_clk = 0;
-// gram[0xCB00] = 0;
-
-/*
-//This is where the interrupt mask is restored in CC... Hmm...
-//This enables interrupts *after* the previous interrupt has occurred... Hmm.
-//Could $C80F (rom_pia_ctrlb) be the IRQ inhibit? Yes, it is!
-
- // the IRQ signal comes into CB1, and is set to VA11
- pia_1_cb1_w(0, scanline & 0x20);
-...
- // the COUNT240 signal comes into CA1, and is set to the logical AND of VA10-VA13
- pia_1_ca1_w(0, 0);
-...
- // the COUNT240 signal comes into CA1, and is set to the logical AND of VA10-VA13
- pia_1_ca1_w(0, 1);
-*/
-
-//WriteLog("--> Start of frame...\n");
- for(int i=0; i<3; i++)
- {
-//Not sure, but this *might* fix IRQ problem...
-//Checking the PIA IRQ mask for an IRQ seems to work OK. Now if only the timing elsewhere was right...
- if (gram[0xC80F] & 0x01)
- mainCPU.cpuFlags |= V6809_ASSERT_LINE_IRQ;//*/
-
- Execute6809(&mainCPU, 4000);
- mainCPU.clock -= 4000; // Remove 4K ticks from clock (in case it overflowed)
-//Not sure, but this *might* fix IRQ problem...
-//Checking the PIA IRQ mask for an IRQ seems to work OK. Now if only the timing elsewhere was right...
-/* if (gram[0xC80F] & 0x01)
- mainCPU.cpuFlags |= V6809_ASSERT_LINE_IRQ;//*/
-
- gram[0xCB00] += 64; // Update video counter...
- }
-
-//Hmm.
-/*if (gram[0xC80E] & 0x01)
- mainCPU.cpuFlags |= V6809_ASSERT_LINE_IRQ;//*/
-//48 lines... (+ 16)
-//gram[0xCB00] = 0;
- Execute6809(&mainCPU, 3000);
- mainCPU.clock -= 3000; // Remove 3K ticks from clock (in case it overflowed)
-//Not sure, but this *might* fix IRQ problem...
-//if (gram[0xC80F] & 0x01)
-//This isn't the right port on the PIA, but it does seem to make it through the demo now...
-//Lesse if this works... Seems to!
- if (gram[0xC80D] & 0x01) // Do COUNT240 IRQ (if enabled!)
- mainCPU.cpuFlags |= V6809_ASSERT_LINE_IRQ;
-
-/*if (gram[0xC80F] & 0x01)
- mainCPU.cpuFlags |= V6809_ASSERT_LINE_IRQ;
-gram[0xCB00] = 0; //*/
-
- gram[0xCB00] += 48; // Update video counter...
-
- Execute6809(&mainCPU, 1000);
- mainCPU.clock -= 1000; // Remove 1K ticks from clock (in case it overflowed)
-//Eh?
-//Ok, this is the interrupt it's looking for, but still...
-//if (gram[0xC80F] & 0x01)
-// mainCPU.cpuFlags |= V6809_ASSERT_LINE_IRQ;
-
- gram[0xCB00] += 16; // Update video counter...
-
-// RenderScreenBuffer();
- RenderScreenBuffer2(); // 1 frame = 16667 cycles
-// WriteLog("Main: Rendered back buffer. [6809 PC=%04X]\n", pcr);
-
- Execute6809(&mainCPU, 667); // Do QnD VBLANK
-
- // 1/60 sec = ? ms (16.6 ms)
- while (SDL_GetTicks() - startTicks < 16); // Wait for next frame...
-
-//kludge, temp...
-//Very interesting! It's the palette rotation that's slowing it down!
-//Fixed now, but this allows the color rotation while the wrong timing is in effect...
-/*for(int i=0; i<16; i++)
- WrMem(0xC000 + i, gram[0x9C26 + i]);//*/
- }
-
-/*uint16 pc = 0x15BA;
-for(int i=0; i<200; i++)
-//while (pc < 0x9000)
- pc += Decode6809(pc);//*/
-
-#else
-
- running = true; // Set running status...
-
- InitializeEventList(); // Clear the event list before we use it...
- SetCallbackTime(FrameCallback, 16666.66666667); // Set frame to fire at 1/60 s interval
-// SetCallbackTime(BlinkTimer, 250000); // Set up blinking at 1/4 s intervals
- SetCallbackTime(ScanlineCallback, 520.83333334); // Set scanline callback at 1/32 of frame
-// SetCallbackTime(ScanlineCallback, 520.83333334*32.00); // Set scanline callback at 1/32 of frame
+ keys = SDL_GetKeyboardState(NULL);
+ srom[0xF800] = 0x37; // Fix checksum so Self-Test works...
+ running = true; // Set running status...
+
+ InitializeEventList(); // Clear the event list before we use it...
+ SetCallbackTime(FrameCallback, FRAME_DURATION_IN_CYCLES * M6809_CYCLE_IN_USEC);
+ SetCallbackTime(ScanlineCallback, SG2_PIA_CALLBACK_DURATION);
+ clockFrameStart = mainCPU.clock;
startTicks = SDL_GetTicks();
WriteLog("Entering main loop...\n");
{
double timeToNextEvent = GetTimeToNextEvent();
Execute6809(&mainCPU, USEC_TO_M6809_CYCLES(timeToNextEvent));
-//We MUST remove a frame's worth of time in order for the CPU to function... !!! FIX !!!
-//(Fix so that this is not a requirement!)
- mainCPU.clock -= USEC_TO_M6809_CYCLES(timeToNextEvent);
HandleNextEvent();
}
-#ifdef __DEBUG__
-WriteLog("\n");
-WriteLog("$C900 = $%02X (0=RAM)\n", gram[0xC900]);
-WriteLog("PC: %04X, X: %04X, Y: %04X, S: %04X, U: %04X, A: %02X, B: %02X, DP: %02X, CC: %02X\n", mainCPU.pc, mainCPU.x, mainCPU.y, mainCPU.s, mainCPU.u, mainCPU.a, mainCPU.b, mainCPU.dp, mainCPU.cc);
-WriteLog("\n");
-
-/*uint16 pc = mainCPU.pc;//0x15BA;
-for(int i=0; i<200; i++)
-//while (pc < 0x9000)
-{
- pc += Decode6809(pc);
- WriteLog("\n");
-}//*/
-
-/*uint32 pc = 0;
-while (pc < 0xFFFF)
-{
- pc += Decode6809(pc);
- WriteLog("\n");
-}//*/
-#endif
-
-#endif
-
SoundDone();
VideoDone();
SaveCMOS();
return 0;
}
-static void FrameCallback(void)
+//
+// Load a file into RAM/ROM image space
+//
+bool LoadImg(const char * filename, uint8_t * ram, int size)
{
- SDL_PumpEvents(); // Force key events into the buffer.
- gram[0xC804] = gram[0xC806] = gram[0xC80C] = 0; // Reset PIA ports...
-
- if (keys[SDLK_ESCAPE])
- running = false; // ESC to exit...
-
-//Convert this stuff to use the settings module... !!! FIX !!!
- if (keys[SDLK_SEMICOLON])
- gram[0xC804] |= 0x01; // Fire (;)
- if (keys[SDLK_l])
- gram[0xC804] |= 0x02; // Thrust (L)
- if (keys[SDLK_SPACE])
- gram[0xC804] |= 0x04; // Smart Bomb (space)
- if (keys[SDLK_BACKSPACE])
- gram[0xC804] |= 0x08; // Hyperspace (BkSp)
- if (keys[SDLK_2])
- gram[0xC804] |= 0x10; // Two Player Start (2)
- if (keys[SDLK_1])
- gram[0xC804] |= 0x20; // One Player Start (1)
- if (keys[SDLK_RETURN])
- gram[0xC804] |= 0x40; // Reverse (Enter)
- if (keys[SDLK_f])
- gram[0xC804] |= 0x80; // Down (F)
-
- if (keys[SDLK_r])
- gram[0xC806] |= 0x01; // Up (R)
- if (keys[SDLK_a])
- gram[0xC806] |= 0x02; // Inviso (A)
-
- if (keys[SDLK_F1])
- gram[0xC80C] |= 0x01; // Auto up (F1)
- if (keys[SDLK_F2])
- gram[0xC80C] |= 0x02; // Advance (F2)
- if (keys[SDLK_5])
- gram[0xC80C] |= 0x04; // Right Coin (5)
- if (keys[SDLK_F3])
- gram[0xC80C] |= 0x08; // High Score Reset (F3)
- if (keys[SDLK_3])
- gram[0xC80C] |= 0x10; // Left Coin (3)
- if (keys[SDLK_4])
- gram[0xC80C] |= 0x20; // Center Coin (4)
- if (keys[SDLK_F4])
- gram[0xC80C] |= 0x40; // Slam Switch (F4)
-
- if (keys[SDLK_F5]) // Sound CPU self-test (F5)
- soundCPU.cpuFlags |= V6808_ASSERT_LINE_NMI;
- if (keys[SDLK_F6]) // Reset the 6808 (F6)
- soundCPU.cpuFlags |= V6808_ASSERT_LINE_RESET;
-
- RenderScreenBuffer2(); // 1 frame = 1/60 sec ~ 16667 cycles
- SetCallbackTime(FrameCallback, 16666.66666667);
-
- while (SDL_GetTicks() - startTicks < 16); // Wait for next frame...
- startTicks = SDL_GetTicks();
-}
+ FILE * fp = fopen(filename, "rb");
-static void ScanlineCallback(void)
-{
-// CA1 of PIA 1 maps to $C80C-F... <-- Count240 is in PIA1...
-// What about COUNT240???
-
-//wil wok? Yes, but still screws up on the demo...
-/* if (gram[0xCB00] & 0x20)
- if (gram[0xC80F] & 0x01)
- mainCPU.cpuFlags |= V6809_ASSERT_LINE_IRQ;//*/
- if ((gram[0xCB00] & 0x20) && (gram[0xC80F] & 0x01))
- mainCPU.cpuFlags |= V6809_ASSERT_LINE_IRQ;//*/
-
-//Is $C80E COUNT240? Hmm... Doesn't seem to be. Bleh.
-/* if (gram[0xCB00] >= 240)
- gram[0xC80E] = 0xFF;
- else
- gram[0xC80E] = 0x00;//*/
-// gram[0xC80E] = (gram[0xCB00] >= 240 ? 0xFF : 0x00);
+ if (fp == NULL)
+ return false;
- gram[0xCB00] += 8; // Update video counter...
+ size_t ignoredResult = fread(ram, 1, size, fp);
+ fclose(fp);
- SetCallbackTime(ScanlineCallback, 520.83333334); // Set scanline callback at 1/32 of frame
+ return true;
}
-
-/*
-; With correct timing, but no color cycling
-
---> Start of frame...
-WrMem: Writing address C80F with 34 [PC=15C3, $CB00=40]
-At $07AD. $6E: 00
-At $0B66. $6E: 00
-At $0CF4. $6E: 00
-At $0CCB. $6E: 00
-WrMem: Writing address C80F with 35 [PC=1644, $CB00=40]
-WrMem: Writing address C80F with 34 [PC=15C3, $CB00=80]
-At $0718. $6E: 01
-At $07AD. $6E: 01
-At $0BB8. $6E: 01
-At $0927. $6E: 01
-At $0CF4. $6E: 01
-At $0B66. $6E: 01
-At $16C8. $6E: 01
-WrMem: Writing address C80F with 35 [PC=1644, $CB00=80]
-WrMem: Writing address C80F with 34 [PC=15C3, $CB00=C0]
-WrMem: Writing address C80F with 35 [PC=1644, $CB00=C0]
-
-
-; With incorrect timing, but has color cycling
-
---> Start of frame...
-WrMem: Writing address C80F with 34 [PC=15C3, $CB00=00]
-At $1609. $6E: 00 ; Color cycling...
-At $07AD. $6E: 00
-At $0B66. $6E: 00
-At $0CF4. $6E: 00
-At $0CCB. $6E: 00
-WrMem: Writing address C80F with 35 [PC=1644, $CB00=00]
-WrMem: Writing address C80F with 34 [PC=15C3, $CB00=40]
-WrMem: Writing address C80F with 35 [PC=1644, $CB00=40]
-WrMem: Writing address C80F with 34 [PC=15C3, $CB00=80]
-At $0718. $6E: 01
-At $07AD. $6E: 01
-At $0BB8. $6E: 01
-At $0927. $6E: 01
-At $0CF4. $6E: 01
-At $0B66. $6E: 01
-At $16C8. $6E: 01
-WrMem: Writing address C80F with 35 [PC=1644, $CB00=80]
-WrMem: Writing address C80F with 34 [PC=15C3, $CB00=C0]
-WrMem: Writing address C80F with 35 [PC=1644, $CB00=C0]
-
-
-
- Stargate
- --------
-
- 0000-8FFF ROM (for Blaster, 0000-3FFF is a bank of 12 ROMs)
- 0000-97FF Video RAM Bank switched with ROM (96FF for Blaster)
- 9800-BFFF RAM
- 0xBB00 Blaster only, Color 0 for each line (256 entry)
- 0xBC00 Blaster only, Color 0 flags, latch color only if bit 0 = 1 (256 entry)
- Do something else with the bit 1, I do not know what
- C000-CFFF I/O
- D000-FFFF ROM
-
- C000-C00F color_registers (16 bytes of BBGGGRRR)
-
- C804 widget_pia_dataa (widget = I/O board)
- C805 widget_pia_ctrla
- C806 widget_pia_datab
- C807 widget_pia_ctrlb (CB2 select between player 1 and player 2
- controls if Table or Joust)
- bits 5-3 = 110 = player 2
- bits 5-3 = 111 = player 1
-
- C80C rom_pia_dataa
- C80D rom_pia_ctrla
- C80E rom_pia_datab
- bit 0 \
- bit 1 |
- bit 2 |-6 bits to sound board
- bit 3 |
- bit 4 |
- bit 5 /
- bit 6 \
- bit 7 /Plus CA2 and CB2 = 4 bits to drive the LED 7 segment
- C80F rom_pia_ctrlb
-
- C900 rom_enable_scr_ctrl Switch between video ram and rom at 0000-97FF
-
- Stargate
- --------
- C804 widget_pia_dataa (widget = I/O board)
- bit 0 Fire
- bit 1 Thrust
- bit 2 Smart Bomb
- bit 3 HyperSpace
- bit 4 2 Players
- bit 5 1 Player
- bit 6 Reverse
- bit 7 Down
-
- C806 widget_pia_datab
- bit 0 Up
- bit 1 Inviso
- bit 2
- bit 3
- bit 4
- bit 5
- bit 6
- bit 7 0 = Upright 1 = Table
-
- C80C rom_pia_dataa
- bit 0 Auto Up
- bit 1 Advance
- bit 2 Right Coin (High Score Reset in schematics)
- bit 3 High Score Reset (Left Coin in schematics)
- bit 4 Left Coin (Center Coin in schematics)
- bit 5 Center Coin (Right Coin in schematics)
- bit 6 Slam Door Tilt
- bit 7 Hand Shake from sound board
-*/
-
-
-/*
-
-static MEMORY_READ_START( williams_readmem )
- { 0x0000, 0x97ff, MRA_BANK1 },
- { 0x9800, 0xbfff, MRA_RAM },
- { 0xc804, 0xc807, pia_0_r },
- { 0xc80c, 0xc80f, pia_1_r },
- { 0xcb00, 0xcb00, williams_video_counter_r },
- { 0xcc00, 0xcfff, MRA_RAM },
- { 0xd000, 0xffff, MRA_ROM },
-MEMORY_END
-
-
-static MEMORY_WRITE_START( williams_writemem )
- { 0x0000, 0x97ff, williams_videoram_w, &williams_bank_base, &videoram_size },
- { 0x9800, 0xbfff, MWA_RAM },
- { 0xc000, 0xc00f, paletteram_BBGGGRRR_w, &paletteram },
- { 0xc804, 0xc807, pia_0_w },
- { 0xc80c, 0xc80f, pia_1_w },
- { 0xc900, 0xc900, williams_vram_select_w },
- { 0xca00, 0xca07, williams_blitter_w, &williams_blitterram },
- { 0xcbff, 0xcbff, watchdog_reset_w },
- { 0xcc00, 0xcfff, MWA_RAM },
- { 0xd000, 0xffff, MWA_ROM },
-MEMORY_END
-
-static MEMORY_READ_START( sound_readmem )
- { 0x0000, 0x007f, MRA_RAM },
- { 0x0400, 0x0403, pia_2_r },
- { 0x8400, 0x8403, pia_2_r }, // used by Colony 7, perhaps others?
- { 0xb000, 0xffff, MRA_ROM }, // most games start at $F000, Sinistar starts at $B000
-MEMORY_END
-
-
-static MEMORY_WRITE_START( sound_writemem )
- { 0x0000, 0x007f, MWA_RAM },
- { 0x0400, 0x0403, pia_2_w },
- { 0x8400, 0x8403, pia_2_w }, // used by Colony 7, perhaps others?
- { 0xb000, 0xffff, MWA_ROM }, // most games start at $F000, Sinistar starts at $B000
-MEMORY_END
-
-MACHINE_INIT( williams )
+//
+// Save CMOS ram
+//
+void SaveCMOS(void)
{
- // reset the PIAs
- pia_reset();
-
- // reset the ticket dispenser (Lotto Fun)
- ticket_dispenser_init(70, TICKET_MOTOR_ACTIVE_LOW, TICKET_STATUS_ACTIVE_HIGH);
+ FILE * fp = fopen(CMOS, "wb");
- // set a timer to go off every 16 scanlines, to toggle the VA11 line and update the screen
- timer_set(cpu_getscanlinetime(0), 0, williams_va11_callback);
+ if (fp == NULL)
+ {
+ WriteLog("CMOS RAM not saved!\n");
+ return;
+ }
- // also set a timer to go off on scanline 240
- timer_set(cpu_getscanlinetime(240), 0, williams_count240_callback);
+ size_t ignoredResult = fwrite(gram + 0xCC00, 1, 1024, fp);
+ fclose(fp);
}
-
-static void williams_va11_callback(int scanline)
+//
+// Load state save file
+//
+bool LoadMachineState(void)
{
- // the IRQ signal comes into CB1, and is set to VA11
- pia_1_cb1_w(0, scanline & 0x20);
-
- // update the screen while we're here
- force_partial_update(scanline - 1);
+ FILE * fp = fopen(SAVESTATE, "rb");
- // set a timer for the next update
- scanline += 8;
- if (scanline >= 256) scanline = 0;
- timer_set(cpu_getscanlinetime(scanline), scanline, williams_va11_callback);
-}
+ if (fp == NULL)
+ return false;
+ // This is kinda crappy--we don't do any sanity checking here!!!
+ size_t ignored = fread(gram, 1, 0x10000, fp);
+ ignored = fread(sram, 1, 0x10000, fp);
+ ignored = fread(&mainCPU, 1, sizeof(V6809REGS), fp);
+ ignored = fread(&soundCPU, 1, sizeof(V6808REGS), fp);
+ ignored = fread(&pia1, 1, sizeof(V6821PIA), fp);
+ ignored = fread(&pia2, 1, sizeof(V6821PIA), fp);
+ fclose(fp);
-static void williams_count240_off_callback(int param)
-{
- // the COUNT240 signal comes into CA1, and is set to the logical AND of VA10-VA13
- pia_1_ca1_w(0, 0);
-}
+ // Set up backbuffer... ;-)
+ for(uint16_t i=0x0006; i<0x97F8; i++) // Screen memory
+ WrMem6809(i, gram[i]);
+ for(uint16_t i=0xC000; i<=0xC00F; i++) // Palette memory
+ WrMem6809(i, gram[i]);
-static void williams_count240_callback(int param)
-{
- // the COUNT240 signal comes into CA1, and is set to the logical AND of VA10-VA13
- pia_1_ca1_w(0, 1);
+ paletteDirty = true;
- // set a timer to turn it off once the scanline counter resets
- timer_set(cpu_getscanlinetime(0), 0, williams_count240_off_callback);
+ mainCPU.RdMem = RdMem6809; // Make sure our function pointers are
+ mainCPU.WrMem = WrMem6809; // pointing to the right places!
+ soundCPU.RdMem = RdMem6808;
+ soundCPU.WrMem = WrMem6808;
+ mainCPU.clock = 0; // Zero out our clocks...
+ soundCPU.clock = 0;
+ mainCPU.clockOverrun = 0; // And overrun values...
+//notyet soundCPU.clockOverrun = 0;
+ pia1.IRQA = NULL;
+ pia1.IRQB = NULL;
+ pia2.IRQA = Handle6809IRQ;
+ pia2.IRQB = Handle6809IRQ;
- // set a timer for next frame
- timer_set(cpu_getscanlinetime(240), 0, williams_count240_callback);
+ return true;
}
-
-static void williams_main_irq(int state)
+//
+// Save state save file
+//
+void SaveMachineState(void)
{
- // IRQ to the main CPU
- cpu_set_irq_line(0, M6809_IRQ_LINE, state ? ASSERT_LINE : CLEAR_LINE);
-}
+ FILE * fp = fopen(SAVESTATE, "wb");
+ if (fp == NULL)
+ {
+ WriteLog("Machine state not saved!\n");
+ return;
+ }
-static void williams_main_firq(int state)
-{
- // FIRQ to the main CPU
- cpu_set_irq_line(0, M6809_FIRQ_LINE, state ? ASSERT_LINE : CLEAR_LINE);
+ size_t ignored = fwrite(gram, 1, 0x10000, fp);
+ ignored = fwrite(sram, 1, 0x10000, fp);
+ ignored = fwrite(&mainCPU, 1, sizeof(V6809REGS), fp);
+ ignored = fwrite(&soundCPU, 1, sizeof(V6808REGS), fp);
+ ignored = fwrite(&pia1, 1, sizeof(V6821PIA), fp);
+ ignored = fwrite(&pia2, 1, sizeof(V6821PIA), fp);
+ fclose(fp);
}
-
-static void williams_snd_irq(int state)
+//
+// 6809 memory functions
+//
+uint8_t RdMem6809(uint16_t addr)
{
- // IRQ to the sound CPU
- cpu_set_irq_line(1, M6800_IRQ_LINE, state ? ASSERT_LINE : CLEAR_LINE);
-}
+ uint8_t b;
+ if (addr >= 0x9000 && addr <= 0xCFFF) // No ROM between $9000 - $CFFF...
+ b = gram[addr];
+ else
+ {
+ if (!gram[0xC900] && addr <= 0x8FFF) // Check RAM $C900 bank switch
+ b = gram[addr];
+ else
+ b = grom[addr];
+ }
-READ_HANDLER( williams_video_counter_r )
-{
- return cpu_getscanline() & 0xFC;
-}
+ if ((addr >= 0xC804) && (addr <= 0xC807))
+ b = pia1.Read(addr);
+ else if ((addr >= 0xC80C) && (addr <= 0xC80F))
+ b = pia2.Read(addr);
+ // A wee kludge (though I doubt it reads from anywhere other than $CB00)...
+ else if ((addr & 0xFF00) == 0xCB00)
+ {
+ double elapsedCycles = (double)(GetCurrentV6809Clock() - clockFrameStart);
+ uint32_t scanline = (uint32_t)(elapsedCycles / SCANLINE_DURATION_IN_CYCLES);
+ b = (uint8_t)scanline & 0xFC; // Only bits 2-7 are connected...
+ }
-// Special PIA 0 for Stargate, to handle the controls
-struct pia6821_interface stargate_pia_0_intf =
-{
- //inputs : A/B,CA/B1,CA/B2 / stargate_input_port_0_r, input_port_1_r, 0, 0, 0, 0,
- //outputs: A/B,CA/B2 / 0, 0, 0, 0,
- //irqs : A/B / 0, 0
-};
+ return b;
+}
-// Generic PIA 1, maps to input port 2, sound command out, and IRQs
-struct pia6821_interface williams_pia_1_intf =
+void WrMem6809(uint16_t addr, uint8_t b)
{
- //inputs : A/B,CA/B1,CA/B2 / input_port_2_r, 0, 0, 0, 0, 0,
- //outputs: A/B,CA/B2 / 0, williams_snd_cmd_w, 0, 0,
- //irqs : A/B / williams_main_irq, williams_main_irq
-};
+ gram[addr] = b;
-// Generic PIA 2, maps to DAC data in and sound IRQs
-struct pia6821_interface williams_snd_pia_intf =
-{
- //inputs : A/B,CA/B1,CA/B2 / 0, 0, 0, 0, 0, 0,
- //outputs: A/B,CA/B2 / DAC_0_data_w, 0, 0, 0,
- //irqs : A/B / williams_snd_irq, williams_snd_irq
-};
+ if (addr >= 0x0006 && addr <= 0x97F6) // 304 pixels 152-128=24-16=8
+ {
+ // NOTE: Screen was 304 x 256, but we truncate the vertical dimension here...
+ uint16_t sx = (addr >> 7) & 0x01FE, sy = addr & 0x00FF;
-static DRIVER_INIT( stargate )
-{
- // CMOS configuration
- CONFIGURE_CMOS(0xCC00, 0x400);
+ if (sy >= 6 && sy <= 245)
+ {
+ uint32_t saddr = 8 + sx + ((sy - 6) * 320); // Calc screen address
+ scrBuffer[saddr + 0] = palette[color[b >> 4]];
+ scrBuffer[saddr + 1] = palette[color[b & 0x0F]];
+ }
+ }
+ else if (addr >= 0xC000 && addr <= 0xC00F)
+ {
+ // This approach doesn't take the BG color to the edges of the screen
+ color[addr & 0x0F] = b;
+ paletteDirty = true;
+ }
+ else if (addr == 0xC80E)
+ {
+ // Only write if not writing the DDR...
+ if ((pia2.crb & 0x04) != 0)
+ {
+ sram[0x0402] = b; // Connect PIAs in 6809 & 6808
+ soundCPU.cpuFlags |= V6808_LINE_IRQ; // Start sound IRQ
+ }
+ }
- // PIA configuration
- CONFIGURE_PIAS(stargate_pia_0_intf, williams_pia_1_intf, williams_snd_pia_intf);
+ if ((addr >= 0xC804) && (addr <= 0xC807))
+ pia1.Write(addr, b);
+ else if ((addr >= 0xC80C) && (addr <= 0xC80F))
+ pia2.Write(addr, b);
}
-
-int cpu_getscanline(void)
+void Handle6809IRQ(bool state)
{
- return (int)(timer_timeelapsed(refresh_timer) * scanline_period_inv);
+ // N.B.: The IRQ line is active LOW
+ if (state)
+ {
+ // We do both, because we don't know if we're in an execution context or not... :-P
+ SetLineOfCurrentV6809(V6809_LINE_IRQ);
+ mainCPU.cpuFlags |= V6809_LINE_IRQ;
+ }
+ else
+ {
+ // We do both, because we don't know if we're in an execution context or not... :-P
+ ClearLineOfCurrentV6809(V6809_LINE_IRQ);
+ mainCPU.cpuFlags &= ~V6809_LINE_IRQ;
+ }
}
- *************************************
- *
- * Returns time until given scanline
- *
- *************************************
-
-double cpu_getscanlinetime(int scanline)
+//
+// 6808 memory functions
+//
+uint8_t RdMem6808(uint16_t addr)
{
- double scantime = timer_starttime(refresh_timer) + (double)scanline * scanline_period;
- double abstime = timer_get_time();
- double result;
-
- // if we're already past the computed time, count it for the next frame
- if (abstime >= scantime)
- scantime += TIME_IN_HZ(Machine->drv->frames_per_second);
-
- // compute how long from now until that time
- result = scantime - abstime;
-
- // if it's small, just count a whole frame
- if (result < TIME_IN_NSEC(1))
- result = TIME_IN_HZ(Machine->drv->frames_per_second);
- return result;
+ return (addr < 0xF000 ? sram[addr] : srom[addr]);
}
- *************************************
- *
- * Returns time for one scanline
- *
- *************************************
-
-double cpu_getscanlineperiod(void)
+void WrMem6808(uint16_t addr, uint8_t b)
{
- return scanline_period;
+ sram[addr] = b;
}
+//
+// Stargate frame callback
+//
+static void FrameCallback(void)
+{
+ SDL_PumpEvents(); // Force key events into the buffer.
+ pia1.pa = pia1.pb = pia2.pa = 0; // Clear inputs...
+//don't do nuthin'
+// gram[0xC80C] = 0x80;//temp, for testing (Hand Shake from sound board)
-V6809 WrMem: Writing address C80D with 00 [PC=0000, $CB00=00]
-V6809 WrMem: Writing address C80C with 00 [PC=0000, $CB00=00]
-V6809 WrMem: Writing address C80D with 3C [PC=0000, $CB00=00]
-
-V6809 WrMem: Writing address C80F with 00 [PC=0000, $CB00=00]
-V6809 WrMem: Writing address C80E with C0 [PC=0000, $CB00=00]
-V6809 WrMem: Writing address C80F with 3C [PC=0000, $CB00=00]
-
-V6809 WrMem: Writing address C80E with C0 [PC=0000, $CB00=00]
-V6809 WrMem: Writing address C80D with 34 [PC=FE61, $CB00=48]
-V6809 WrMem: Writing address C80F with 34 [PC=FE61, $CB00=48]
-V6809 WrMem: Writing address C80E with 00 [PC=FE61, $CB00=48]
-
-V6809 WrMem: Writing address C80C with 00 [PC=FD92, $CB00=C8]
-V6809 WrMem: Writing address C80D with 00 [PC=FD92, $CB00=C8]
-V6809 WrMem: Writing address C80C with 00 [PC=FD92, $CB00=C8]
-V6809 WrMem: Writing address C80D with 34 [PC=FD92, $CB00=C8]
-
-V6809 WrMem: Writing address C80E with 00 [PC=FD92, $CB00=C8]
-V6809 WrMem: Writing address C80F with 00 [PC=FD92, $CB00=C8]
-V6809 WrMem: Writing address C80E with FF [PC=FD92, $CB00=C8]
-V6809 WrMem: Writing address C80F with 35 [PC=FD92, $CB00=C8]
-
-V6809 WrMem: Writing address C804 with 00 [PC=607B, $CB00=D0]
-V6809 WrMem: Writing address C805 with 00 [PC=607B, $CB00=D0]
-V6809 WrMem: Writing address C804 with 00 [PC=607B, $CB00=D0]
-V6809 WrMem: Writing address C805 with 34 [PC=607B, $CB00=D0]
+ if (keys[SDL_SCANCODE_ESCAPE])
+ running = false; // ESC to exit...
-V6809 WrMem: Writing address C806 with 00 [PC=607B, $CB00=D0]
-V6809 WrMem: Writing address C807 with 00 [PC=607B, $CB00=D0]
-V6809 WrMem: Writing address C806 with 00 [PC=607B, $CB00=D0]
-V6809 WrMem: Writing address C807 with 3E [PC=607B, $CB00=D0]
+ if (keys[settings.keyBindings[S_KEY_FIRE]]) pia1.pa |= 0x01;
+ if (keys[settings.keyBindings[S_KEY_THRUST]]) pia1.pa |= 0x02;
+ if (keys[settings.keyBindings[S_KEY_SMARTBOMB]]) pia1.pa |= 0x04;
+ if (keys[settings.keyBindings[S_KEY_HYPERSPACE]]) pia1.pa |= 0x08;
+ if (keys[settings.keyBindings[S_KEY_2P_START]]) pia1.pa |= 0x10;
+ if (keys[settings.keyBindings[S_KEY_1P_START]]) pia1.pa |= 0x20;
+ if (keys[settings.keyBindings[S_KEY_REVERSE]]) pia1.pa |= 0x40;
+ if (keys[settings.keyBindings[S_KEY_DOWN]]) pia1.pa |= 0x80;
+
+ if (keys[settings.keyBindings[S_KEY_UP]]) pia1.pb |= 0x01;
+ if (keys[settings.keyBindings[S_KEY_INVISO]]) pia1.pb |= 0x02;
+
+ if (keys[settings.keyBindings[S_KEY_AUTO_UP]]) pia2.pa |= 0x01;
+ if (keys[settings.keyBindings[S_KEY_ADVANCE]]) pia2.pa |= 0x02;
+ if (keys[settings.keyBindings[S_KEY_RIGHT_COIN]]) pia2.pa |= 0x04;
+ if (keys[settings.keyBindings[S_KEY_HS_RESET]]) pia2.pa |= 0x08;
+ if (keys[settings.keyBindings[S_KEY_LEFT_COIN]]) pia2.pa |= 0x10;
+ if (keys[settings.keyBindings[S_KEY_CENTER_COIN]]) pia2.pa |= 0x20;
+ if (keys[settings.keyBindings[S_KEY_SLAM_SWITCH]]) pia2.pa |= 0x40;
+
+ if (keys[SDL_SCANCODE_F5]) // Sound CPU self-test (F5)
+ soundCPU.cpuFlags |= V6808_LINE_NMI;
+ if (keys[SDL_SCANCODE_F6]) // Reset the 6808 (F6)
+ soundCPU.cpuFlags |= V6808_LINE_RESET;
+
+ if (paletteDirty)
+ {
+ for(uint32_t addr=0x0006; addr<0x97F7; addr++)
+ {
+ uint16_t sx = (addr >> 7) & 0x01FE, sy = addr & 0x00FF;
-V6809 WrMem: Writing address C80E with 3F [PC=13CB, $CB00=A8]
-V6809 WrMem: Writing address C807 with 3C [PC=60B4, $CB00=90]
-V6809 WrMem: Writing address C80E with 0C [PC=014D, $CB00=80]
+ if (sy > 5 && sy < 246)
+ {
+ uint32_t saddr = 8 + sx + ((sy - 6) * 320); // Calc screen address
+ uint8_t sb = gram[addr];
-V6809 WrMem: Writing address C80F with 34 [PC=014D, $CB00=80]
-V6809 WrMem: Writing address C80F with 35 [PC=014D, $CB00=80]
-V6809 WrMem: Writing address C80F with 34 [PC=0013, $CB00=A8]
-V6809 WrMem: Writing address C80F with 35 [PC=0013, $CB00=A8]
+ scrBuffer[saddr + 0] = palette[color[sb >> 4]];
+ scrBuffer[saddr + 1] = palette[color[sb & 0x0F]];
+ }
+ }
- C80C rom_pia_dataa
- C80D rom_pia_ctrla
- C80E rom_pia_datab
- bit 0 \
- bit 1 |
- bit 2 |-6 bits to sound board
- bit 3 |
- bit 4 |
- bit 5 /
- bit 6 \
- bit 7 /Plus CA2 and CB2 = 4 bits to drive the LED 7 segment
- C80F rom_pia_ctrlb
+ paletteDirty = false;
+ }
-CTRLA = IRQA1 (1 bit) IRQA2 (1 bit) CA2 (3 bits) DDR (1 bit) CA1 (2 bits)
+ static bool fullscreenDebounce = false;
+ if (keys[SDL_SCANCODE_F12])
+ {
+ if (!fullscreenDebounce)
+ {
+ ToggleFullScreen();
+ fullscreenDebounce = true;
+ }
+ }
+ else
+ fullscreenDebounce = false;
-PIA initialization:
+ RenderScreenBuffer(); // 1 frame = 1/60 sec ~ 16667 cycles
+ clockFrameStart = mainCPU.clock;
-00 -> $C80D = PIA2 -> DDR active
-00 -> $C80C = PIA2 DDR -> All input?
+ // Wait for next frame...
+ while (SDL_GetTicks() - startTicks < 16)
+ SDL_Delay(1);
+ startTicks = SDL_GetTicks();
+ SetCallbackTime(FrameCallback, FRAME_DURATION_IN_CYCLES * M6809_CYCLE_IN_USEC);
+}
+static void ScanlineCallback(void)
+{
+/*
+What we've proven so far:
+ - The COUNT240 IRQ *NEVER* fires on MAME driver (it can't, PACTL is never set to allow it and an IRQ never fires anywhere around scanline 240)
+ - In the demo, the IRQs fire on 0, 82 (sometimes, 87, 90-112), 128, & 192
+ - In the HS screen the IRQs fire 0, 64, 128, & 192 exactly
*/
+ double elapsedCycles = (double)(GetCurrentV6809Clock() - clockFrameStart);
+ uint32_t scanline = (uint32_t)((elapsedCycles / SCANLINE_DURATION_IN_CYCLES) + 0.5);
+ // N.B.: The 4 MS line toggles every 2.083 ms
+ // Also: CA1 *never* asserts because PACTL is set to never allow IRQs
+ pia2.CB1(scanline & 0x20 ? true : false);
+ pia2.CA1(scanline >= 240 ? true : false);
+
+ SetCallbackTime(ScanlineCallback, SG2_PIA_CALLBACK_DURATION);
+}
projects / stargem2 / blobdiff