brandin claar / Mbed 2 deprecated 6502vga

6502 RAM/bus emulation with VGA display

Dependencies:   fastlib mbed vga640x480g

Fork of vga640x480graphic by Gert van der Knokke

main.cpp@1:f9ed7e40eccf, 2015-05-03 (annotated)

Committer:
brandin
Date:
Sun May 03 17:48:25 2015 +0000
Revision:
1:f9ed7e40eccf
Parent:
0:770395da503c 
emulating 6502 RAM/bus with VGA display

Who changed what in which revision?

UserRevisionLine numberNew contents of line
gertk 0:770395da503c 1 /*
gertk 0:770395da503c 2 * 640x480 60Hz fullgraphic monochrome VGA Driver demo program
gertk 0:770395da503c 3 *
gertk 0:770395da503c 4 * Copyright (C) 2011 by Ivo van Poorten <ivop(at)euronet.nl>
gertk 0:770395da503c 5 * and Gert van der Knokke <gertk(at)xs4all.nl>
gertk 0:770395da503c 6 * This file is licensed under the terms of the GNU Lesser
gertk 0:770395da503c 7 * General Public License, version 3.
gertk 0:770395da503c 8 *
gertk 0:770395da503c 9 * Inspired by Simon's (not Ford) Cookbook entry and Cliff Biffle's
gertk 0:770395da503c 10 * assembly code.
gertk 0:770395da503c 11 */
gertk 0:770395da503c 12
gertk 0:770395da503c 13 #include "mbed.h"
brandin 1:f9ed7e40eccf 14 #include "vga640x480g.h" // vga p5, p8, p25
brandin 1:f9ed7e40eccf 15
brandin 1:f9ed7e40eccf 16 //Serial display(p9,p10);
brandin 1:f9ed7e40eccf 17
brandin 1:f9ed7e40eccf 18 DigitalOut resety(p17/*, 1*/);
brandin 1:f9ed7e40eccf 19 DigitalOut clocky(p18/*, 1*/);
brandin 1:f9ed7e40eccf 20 DigitalIn rw(p19);
brandin 1:f9ed7e40eccf 21 DigitalOut addressDisable(p20/*, 1*/);
brandin 1:f9ed7e40eccf 22 BusInOut mixBus(p21, p22, p23, p24, p16, p26, p27, p28);
brandin 1:f9ed7e40eccf 23 BusIn addrHigh(p29, p30);
brandin 1:f9ed7e40eccf 24
brandin 1:f9ed7e40eccf 25 BusOut addrLeds(LED1, LED2, LED3, LED4);
brandin 1:f9ed7e40eccf 26 Serial pc(USBTX, USBRX); // tx, rx
brandin 1:f9ed7e40eccf 27
brandin 1:f9ed7e40eccf 28 LocalFileSystem local("local"); // Create the local filesystem under the name "local"
brandin 1:f9ed7e40eccf 29
brandin 1:f9ed7e40eccf 30 char memory[4*256];
brandin 1:f9ed7e40eccf 31
brandin 1:f9ed7e40eccf 32 void halfcycle() {
brandin 1:f9ed7e40eccf 33 wait_ms(1);
brandin 1:f9ed7e40eccf 34 }
brandin 1:f9ed7e40eccf 35
brandin 1:f9ed7e40eccf 36 void busDisplay(int addr, int data, int flags) {
brandin 1:f9ed7e40eccf 37 char tmp[255];
brandin 1:f9ed7e40eccf 38 sprintf(tmp, "%04X %04X", addr, data);
brandin 1:f9ed7e40eccf 39 vga_putstring(400,370,tmp,WHITE);
brandin 1:f9ed7e40eccf 40 // display.putc(0x76);
brandin 1:f9ed7e40eccf 41 // display.putc((addr & 0x00f0) >> 4);
brandin 1:f9ed7e40eccf 42 // display.putc(addr & 0x000f);
brandin 1:f9ed7e40eccf 43 // display.putc((data & 0xf0) >> 4);
brandin 1:f9ed7e40eccf 44 // display.putc(data & 0x0f);
brandin 1:f9ed7e40eccf 45 // display.putc(0x77);
brandin 1:f9ed7e40eccf 46 // display.putc(((addr & 0x0300) >> 8) | (flags << 2));
brandin 1:f9ed7e40eccf 47 // pc.printf("%X %X %X\r\n", addr, data, flags);
brandin 1:f9ed7e40eccf 48 }
gertk 0:770395da503c 49
gertk 0:770395da503c 50 // visual feedback
brandin 1:f9ed7e40eccf 51 //DigitalOut myled(LED1);
gertk 0:770395da503c 52
gertk 0:770395da503c 53 // define serial port for debug
brandin 1:f9ed7e40eccf 54 //Serial linktopc(USBTX,USBRX);
gertk 0:770395da503c 55
brandin 1:f9ed7e40eccf 56 void draw() {
gertk 0:770395da503c 57 // init the VGA subsystem (always do this first!)
brandin 1:f9ed7e40eccf 58 //init_vga();
gertk 0:770395da503c 59
gertk 0:770395da503c 60 int s,t;
gertk 0:770395da503c 61
gertk 0:770395da503c 62 // serial port on at 115200 baud
brandin 1:f9ed7e40eccf 63 //linktopc.baud(115200);
brandin 1:f9ed7e40eccf 64 //setbuf(stdout, NULL); // no buffering for this filehandle
gertk 0:770395da503c 65
gertk 0:770395da503c 66 // clear the screen
gertk 0:770395da503c 67 vga_cls();
gertk 0:770395da503c 68
gertk 0:770395da503c 69 // draw some circles
brandin 1:f9ed7e40eccf 70 //for (t=10; t<200; t+=5)
brandin 1:f9ed7e40eccf 71 //vga_circle(20+t,399-t,t,WHITE);
gertk 0:770395da503c 72
gertk 0:770395da503c 73 // draw some boxes
brandin 1:f9ed7e40eccf 74 //for (t=10; t<100; t+=5)
brandin 1:f9ed7e40eccf 75 //vga_box(400+t,100+t,400+t*2,100+t*2,WHITE);
gertk 0:770395da503c 76
gertk 0:770395da503c 77 // circumfence the screen
gertk 0:770395da503c 78 vga_box(0,0,639,479,WHITE);
gertk 0:770395da503c 79
gertk 0:770395da503c 80 // show the complete character set
gertk 0:770395da503c 81 for (s=0; s<4; s++) {
gertk 0:770395da503c 82 for (t=0; t<64; t++) {
gertk 0:770395da503c 83 vga_putchar(20+t*8,20+16*s,t+s*64,WHITE);
gertk 0:770395da503c 84 }
gertk 0:770395da503c 85 }
gertk 0:770395da503c 86
gertk 0:770395da503c 87 // put a string on screen
brandin 1:f9ed7e40eccf 88 //vga_putstring(400,370,"Hello World!",WHITE);
gertk 0:770395da503c 89
gertk 0:770395da503c 90 // draw some lines
brandin 1:f9ed7e40eccf 91 //vga_line(400,390,500,390,WHITE);
brandin 1:f9ed7e40eccf 92 //vga_line(500,475,600,375,WHITE);
gertk 0:770395da503c 93
gertk 0:770395da503c 94 // draw a filled box
gertk 0:770395da503c 95 vga_filledbox(450,330,550,360,1);
gertk 0:770395da503c 96
gertk 0:770395da503c 97 // draw some more boxes
brandin 1:f9ed7e40eccf 98 //for (t=10; t<320; t+=5)
brandin 1:f9ed7e40eccf 99 //vga_box(100+t,440-t/16,110+t,440+t/16,WHITE);
brandin 1:f9ed7e40eccf 100 return;
brandin 1:f9ed7e40eccf 101 }
brandin 1:f9ed7e40eccf 102
brandin 1:f9ed7e40eccf 103 int main() {
brandin 1:f9ed7e40eccf 104 resety = 1; clocky = 1; addressDisable = 1;
brandin 1:f9ed7e40eccf 105 int addr, haddr, _rw;
brandin 1:f9ed7e40eccf 106 init_vga();
brandin 1:f9ed7e40eccf 107 resety = 0;
brandin 1:f9ed7e40eccf 108 int count = 0;
brandin 1:f9ed7e40eccf 109 // serial port on at 115200 baud
brandin 1:f9ed7e40eccf 110 //pc.baud(115200);
brandin 1:f9ed7e40eccf 111 //setbuf(stdout, NULL); // no buffering for this filehandle
brandin 1:f9ed7e40eccf 112 draw();
brandin 1:f9ed7e40eccf 113 // display.baud(9600);
brandin 1:f9ed7e40eccf 114 // display.putc(0x76);
brandin 1:f9ed7e40eccf 115 // display.putc('h');display.putc('E');display.putc('L');display.putc('o');
brandin 1:f9ed7e40eccf 116 //// pc.printf("Hello World!\r\n");
brandin 1:f9ed7e40eccf 117 // wait(1.0);
brandin 1:f9ed7e40eccf 118 FILE *fp = fopen("/local/6502.OUT", "r");
brandin 1:f9ed7e40eccf 119 for (int i=0; i<256; i++) {
brandin 1:f9ed7e40eccf 120 int c = fgetc(fp);
brandin 1:f9ed7e40eccf 121 addr = 2*256 + i;
brandin 1:f9ed7e40eccf 122 if (c >= 0) {
brandin 1:f9ed7e40eccf 123 memory[addr] = c & 0xff;
brandin 1:f9ed7e40eccf 124 } else {
brandin 1:f9ed7e40eccf 125 break;
brandin 1:f9ed7e40eccf 126 }
brandin 1:f9ed7e40eccf 127 busDisplay(addr, memory[addr], 0);
brandin 1:f9ed7e40eccf 128 //wait_ms(125);
gertk 0:770395da503c 129 }
brandin 1:f9ed7e40eccf 130 // reset vector
brandin 1:f9ed7e40eccf 131 memory[3*256 + 0xfc] = 0;
brandin 1:f9ed7e40eccf 132 memory[3*256 + 0xfd] = 0x80;
brandin 1:f9ed7e40eccf 133 fclose(fp);
brandin 1:f9ed7e40eccf 134 // display.putc(0x76);
brandin 1:f9ed7e40eccf 135 // display.putc('G');display.putc('o');
brandin 1:f9ed7e40eccf 136 // wait(1.0);
brandin 1:f9ed7e40eccf 137 //
brandin 1:f9ed7e40eccf 138 //// pc.printf("run...\r\n");
brandin 1:f9ed7e40eccf 139 while(1) {
brandin 1:f9ed7e40eccf 140 if (count++ == 10) {
brandin 1:f9ed7e40eccf 141 resety = 1;
brandin 1:f9ed7e40eccf 142 }
brandin 1:f9ed7e40eccf 143 //XXX use timer
brandin 1:f9ed7e40eccf 144 clocky = 0;
brandin 1:f9ed7e40eccf 145 mixBus.input();
brandin 1:f9ed7e40eccf 146 addressDisable = 0;
brandin 1:f9ed7e40eccf 147 halfcycle();
brandin 1:f9ed7e40eccf 148 addr = mixBus.read();
brandin 1:f9ed7e40eccf 149 haddr = addrHigh.read();
brandin 1:f9ed7e40eccf 150 addr = addr + (haddr * 256);
brandin 1:f9ed7e40eccf 151 clocky = 1;
brandin 1:f9ed7e40eccf 152 addressDisable = 1;
brandin 1:f9ed7e40eccf 153 _rw = rw;
brandin 1:f9ed7e40eccf 154 if (_rw) {
brandin 1:f9ed7e40eccf 155 mixBus.output();
brandin 1:f9ed7e40eccf 156 mixBus.write(memory[addr]);
brandin 1:f9ed7e40eccf 157 halfcycle();
brandin 1:f9ed7e40eccf 158 } else {
brandin 1:f9ed7e40eccf 159 halfcycle();
brandin 1:f9ed7e40eccf 160 memory[addr] = mixBus.read();
brandin 1:f9ed7e40eccf 161 }
brandin 1:f9ed7e40eccf 162 busDisplay(addr, memory[addr], _rw); //wait_ms(125);
brandin 1:f9ed7e40eccf 163 }
brandin 1:f9ed7e40eccf 164 }