nybbles.c

/*
 *	A minimal INS8073 machine
 */

#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <signal.h>

#ifndef _MSDOS_
#include <termios.h>
#endif

#include <time.h>
#include <unistd.h>
#include <errno.h>

#ifndef _MSDOS_
#include <sys/select.h>
#define TERMINAL_INIT
#endif

#include "ns807x.h"


#define PATCH_ROM  0		// TXTBGN PATCH ( =X'8000 )
#define ROMSIZE    0x1000   // NIBL BASIC ROM SIZE
//#define BASIC_TEXT 0x1400   // NIBL BASIC PROGRAM START


static uint8_t ramrom[65536]; // 64kB RAM
static uint8_t fast;

volatile unsigned done;
static unsigned trace;
struct ns8070 *cpu;
static uint8_t pendc;			/* Pending char */
struct timespec pastTime;
void print_vcount();



#ifdef TERMINAL_INIT

unsigned int next_char(void);
int64_t get_cputime();

int check_chario(void)
{
	fd_set i, o;
	struct timeval tv;
	unsigned int r = 0;

	FD_ZERO(&i);
	FD_SET(0, &i);
	FD_ZERO(&o);
	FD_SET(1, &o);
	tv.tv_sec = 0;
	tv.tv_usec = 0;

	if (select(2, &i, &o, NULL, &tv) == -1) {
		if (errno == EINTR)
			return 0;
		perror("select");
		exit(1);
	}
	if (FD_ISSET(0, &i))
		r |= 1;
	if (FD_ISSET(1, &o))
		r |= 2;
	return r;
}

void ns8070_emu_chario(void)
{
	if (check_chario() & 1) {
		pendc  = next_char();
		/* The TinyBASIC expects break type conditions
		 that persist for a while - this is a fudge */
		if (pendc == 3)
			ns8070_set_a(cpu, 0);
		else
			ns8070_set_a(cpu, 1);
	}
}

static struct termios saved_term, term;

static void cleanup(int sig)
{
	tcsetattr(0, TCSADRAIN, &saved_term);
	done = 1;
}

static void exit_cleanup(void)
{
	tcsetattr(0, TCSADRAIN, &saved_term);
	int64_t t = get_cputime();
	print_vcount(t);
}

void terminal_init()
{
	if (tcgetattr(0, &term) == 0) {
		saved_term = term;
		atexit(exit_cleanup);
		signal(SIGINT, cleanup);
		signal(SIGQUIT, cleanup);
		signal(SIGPIPE, cleanup);
		term.c_lflag &= ~(ICANON | ECHO);
		term.c_cc[VMIN] = 0;
		term.c_cc[VTIME] = 1;
		term.c_cc[VINTR] = 0;
		term.c_cc[VSUSP] = 0;
		term.c_cc[VSTOP] = 0;
		tcsetattr(0, TCSADRAIN, &term);
	}
}

int  ns8070_emu_getc(void)
{
	int rc;
	uint8_t r = pendc;
		if (r) {
			pendc = 0;
			ns8070_set_a(cpu, 1);
			rc = write(1, &r, 1);
		}
	return r;
	(void)rc;
}

void ns8070_emu_putc(char r)
{
	int rc = write(1, &r, 1);
	(void)rc;
}

unsigned int next_char(void)
{
	char c;
	if (read(0, &c, 1) != 1) {
		printf("(tty read without ready byte)\n");
		return 0xFF;
	}
	if (c == 0x0A)
		c = '\r';

	if (c == 0x1a) { // ^Z
		exit(1);
	}
	if (c == 0x1b) { // ESC
		exit(1);
	}
	if (c == 0x7f) { // ESC
		c = 0x08;
	}
	if( (c>='a')&&(c<='z') ) {c=c-0x20;}
	
	
	return c;
}

#else
// MSDOS:::

void terminal_init() {}
void ns8070_emu_chario(void) {}

int  ns8070_emu_getc(void)
{
	char c;
	c = getchar();
	if (c == 0x0A)
		c = '\r';

	if (c == 0x1a) { // ^Z
		exit(1);
	}
	if (c == 0x1b) { // ESC
		exit(1);
	}
	if (c == 0x7f) { // ESC
		c = 0x08;
	}
	if( (c>='a')&&(c<='z') ) {c=c-0x20;}
	
	
	return c;
}

void ns8070_emu_putc(char r)
{
	putchar(r);
}

#endif





int64_t get_cputime() {
	struct timespec currentTime;
	int64_t diffn;
	int64_t diffs;
	int64_t diffu;
	clock_gettime(CLOCK_REALTIME, &currentTime);
	
//	printf("Current Time: %lu Sec + %lu nanoSec.\n",
//			              (long)currentTime.tv_sec, currentTime.tv_nsec);

	diffn = currentTime.tv_nsec - pastTime.tv_nsec;
	diffs = currentTime.tv_sec  - pastTime.tv_sec;
	
	diffu  = diffn / 1000;
	diffu += diffs * 1000 * 1000;
	
	pastTime = currentTime;
	return diffu;
}

static void usage(void)
{
	fprintf(stderr,
		"flexbox: [-f] -r rompath] [-d debug]\n");
	exit(EXIT_FAILURE);
}

/****************************************************************************
 *	メモリー内容をダンプ.
 ****************************************************************************
 */
void mem_dump(char *msg,int adr,void *ptr,int len)
{
	unsigned char *p = (unsigned char *)ptr;
	int i;//,j,c;
	fprintf(stderr,"%s:\n",msg);

	for(i=0; i<len; i++) {
		if( (i & 15) == 0 ) fprintf(stderr,"%04x",adr);
		if( (i & 15) == 8 ) fprintf(stderr," ");
		fprintf(stderr," %02x",*p);
		p++;adr++;
		if( (i & 15) == 15 ) {
			fprintf(stderr,"\n");
		}
	}
	fprintf(stderr,"\n");
}

void dumpreg(struct ns8070 *cpu)
{
	mem_dump("rom",0xff00,&cpu->rom[0xffc0],64);
}

int main(int argc, char *argv[])
{
/*	static struct timespec tc; */
	int opt;
	int fd;
	int rom = 1;
	char *rompath = "nibl3.bin";
/*	unsigned int cycles = 0; */

	while ((opt = getopt(argc, argv, "d:fi:r:")) != -1) {
		switch (opt) {
		case 'r':
			rompath = optarg;
			break;
		case 'd':
			trace = atoi(optarg);
			break;
		case 'f':
			fast = 1;
			break;
		default:
			usage();
		}
	}
	if (optind < argc)
		usage();

		
	if (rom) {
		//memset(ramrom,0xff,sizeof(ramrom) );

		fd = open(rompath, O_RDONLY);
		if (fd == -1) {
			perror(rompath);
			exit(EXIT_FAILURE);
		}
		if (read(fd, ramrom, ROMSIZE) != ROMSIZE) {
			fprintf(stderr, "nybbles: short rom '%s'.\n",
				rompath);
//			exit(EXIT_FAILURE);
		}
		close(fd);

#if PATCH_ROM 
		// TXTBGN PATCH ( =X'8000 )
		ramrom[0x0c]=(BASIC_TEXT/256) ;   // BASIC PROGRAM TEXT AREA
#endif
	}

	/* Patch in our I/O hooks */
	cpu = ns8070_create(ramrom);
	ns8070_reset(cpu);
	ns8070_trace(cpu, trace & TRACE_CPU);
	ns8070_set_a(cpu, 1);
	ns8070_set_b(cpu, 1);

	terminal_init();
	get_cputime();
	ns8070_executes(cpu);
	exit(0);
}