Revision 1:f9ed7e40eccf, committed 2015-05-03

Comitter:

brandin

Date:

Sun May 03 17:48:25 2015 +0000

Parent:

0:770395da503c

Commit message:

emulating 6502 RAM/bus with VGA display

Changed in this revision

diff -r 770395da503c -r f9ed7e40eccf main.cpp
--- a/main.cpp	Wed Jul 27 19:44:20 2011 +0000
+++ b/main.cpp	Sun May 03 17:48:25 2015 +0000
@@ -11,35 +11,68 @@
  */
  
 #include "mbed.h"
-#include "vga640x480g.h"
+#include "vga640x480g.h" // vga p5, p8, p25
+
+//Serial display(p9,p10);
+
+DigitalOut resety(p17/*, 1*/);
+DigitalOut clocky(p18/*, 1*/);
+DigitalIn rw(p19);
+DigitalOut addressDisable(p20/*, 1*/);
+BusInOut mixBus(p21, p22, p23, p24, p16, p26, p27, p28); 
+BusIn addrHigh(p29, p30);
+
+BusOut addrLeds(LED1, LED2, LED3, LED4);
+Serial pc(USBTX, USBRX); // tx, rx
+
+LocalFileSystem local("local");               // Create the local filesystem under the name "local"
+
+char memory[4*256];
+
+void halfcycle() {
+    wait_ms(1);
+}
+
+void busDisplay(int addr, int data, int flags) {
+    char tmp[255];
+    sprintf(tmp, "%04X %04X", addr, data);
+    vga_putstring(400,370,tmp,WHITE);
+//    display.putc(0x76);
+//    display.putc((addr & 0x00f0) >> 4);
+//    display.putc(addr & 0x000f);
+//    display.putc((data & 0xf0) >> 4);
+//    display.putc(data & 0x0f);
+//    display.putc(0x77);
+//    display.putc(((addr & 0x0300) >> 8) | (flags << 2));
+//    pc.printf("%X %X %X\r\n", addr, data, flags);
+}
 
 // visual feedback
-DigitalOut myled(LED1);
+//DigitalOut myled(LED1);
 
 // define serial port for debug
-Serial linktopc(USBTX,USBRX);
+//Serial linktopc(USBTX,USBRX);
 
-int main() {
+void draw() {
     // init the VGA subsystem (always do this first!)
-    init_vga();
+    //init_vga();
 
     int s,t;
 
     // serial port on at 115200 baud
-    linktopc.baud(115200);
-    setbuf(stdout, NULL); // no buffering for this filehandle
-    
+    //linktopc.baud(115200);
+    //setbuf(stdout, NULL); // no buffering for this filehandle
     
     // clear the screen
     vga_cls();
     
     // draw some circles
-    for (t=10; t<200; t+=5)
-    vga_circle(20+t,399-t,t,WHITE);
+    //for (t=10; t<200; t+=5)
+    //vga_circle(20+t,399-t,t,WHITE);
 
     // draw some boxes
-    for (t=10; t<100; t+=5)
-    vga_box(400+t,100+t,400+t*2,100+t*2,WHITE);
+    //for (t=10; t<100; t+=5)
+    //vga_box(400+t,100+t,400+t*2,100+t*2,WHITE);
   
     // circumfence the screen
     vga_box(0,0,639,479,WHITE);
@@ -52,23 +85,80 @@
     }
 
     // put a string on screen
-    vga_putstring(400,370,"Hello World!",WHITE);
+    //vga_putstring(400,370,"Hello World!",WHITE);
 
     // draw some lines
-    vga_line(400,390,500,390,WHITE);
-    vga_line(500,475,600,375,WHITE);
+    //vga_line(400,390,500,390,WHITE);
+    //vga_line(500,475,600,375,WHITE);
 
     // draw a filled box
     vga_filledbox(450,330,550,360,1);
 
     // draw some more boxes
-    for (t=10; t<320; t+=5)
-    vga_box(100+t,440-t/16,110+t,440+t/16,WHITE);
-    
-    
-    // all done
-    while (1){
-         wait(1);
-       myled=!myled;
+    //for (t=10; t<320; t+=5)
+    //vga_box(100+t,440-t/16,110+t,440+t/16,WHITE);
+    return;
+}
+
+int main() {
+    resety = 1; clocky = 1; addressDisable = 1;  
+    int addr, haddr, _rw;
+    init_vga();
+    resety = 0;
+    int count = 0;
+    // serial port on at 115200 baud
+    //pc.baud(115200);
+    //setbuf(stdout, NULL); // no buffering for this filehandle
+    draw();
+//    display.baud(9600);
+//    display.putc(0x76);
+//    display.putc('h');display.putc('E');display.putc('L');display.putc('o');
+////    pc.printf("Hello World!\r\n");
+   // wait(1.0);
+    FILE *fp = fopen("/local/6502.OUT", "r");
+    for (int i=0; i<256; i++) {
+        int c = fgetc(fp);
+        addr = 2*256 + i;
+        if (c >= 0) {
+            memory[addr] = c & 0xff;
+        } else {
+            break;
+        }
+        busDisplay(addr, memory[addr], 0);
+        //wait_ms(125);
     }
- }
+    // reset vector   
+    memory[3*256 + 0xfc] = 0;
+    memory[3*256 + 0xfd] = 0x80;
+    fclose(fp);
+//    display.putc(0x76);
+//    display.putc('G');display.putc('o');
+//    wait(1.0);
+//    
+////    pc.printf("run...\r\n");
+    while(1) {
+        if (count++ == 10) {
+            resety = 1;
+        }
+        //XXX use timer
+        clocky = 0;
+        mixBus.input();
+        addressDisable = 0;
+        halfcycle();
+        addr = mixBus.read();
+        haddr = addrHigh.read();  
+        addr = addr + (haddr * 256);
+        clocky = 1;
+        addressDisable = 1;
+        _rw = rw;
+        if (_rw) {
+            mixBus.output();
+            mixBus.write(memory[addr]);
+            halfcycle();
+        } else {
+            halfcycle();
+            memory[addr] = mixBus.read();
+        }
+        busDisplay(addr, memory[addr], _rw); //wait_ms(125);
+    }
+}