/* ----------------------------------------------- */
/* A Simulator for the PC-231 Computer             */
/* -- batch version: no print, echo, flush, etc.   */
/* Fritz Ruehr * Willamette University * Fall 1998 */
/* for CS 231: Introduction to Programming         */
/* ----------------------------------------------- */

#include <stdio.h>
#include "bcmds.c"

/* ----------------------------------------------- */
/* Main program: loads program and runs until HALT */

void main(int argc, char* argv[]){

	int runFlag = 1 ;
	int reloadFlag = 1 ;
	int rerunFlag = 0 ;
	int DUMP = 0 ;

	int instr ;		/* current instruction */
	int opcode ;		/* opcode of current instruction */
	int args ;		/* arguments of current instruction */
	
	int i, j, k ;
	char c ;
		
	printf("\n--------------------------------------------------");
	printf("\nWelcome to the PC-231 simulator! [vers. 0.2 BATCH]\n\n");

	/* main run loop */
	
	while (runFlag) {

	/* initialize registers & load program */
	
		haltFlag = 0 ;
		Reg[PCINDEX] = 0 ;
	
		for (i=0; i<REGSIZE; i++)  Reg[i] = 0 ;	

		if(reloadFlag){
			for (i=0; i<RAMSIZE; i++)  RAM[i] = 0 ;
	
			printf("Please enter a program in hexadecimal ");
			printf("(EOF or control-D to stop):\n\n") ;
		
			i=0 ;
			while((scanf("%X", &k) != EOF) && (i<RAMSIZE)) RAM[i++] = NORM(k) ;

		}

		if(!rerunFlag) printf("\n") ;
		
		/* main instruction fetch & execute loop */
	
		printf("\nStarting program execution ...\n") ;
		printf("Note: this \"batch\" version requires \"blind typing\"") ;
		printf("\n--------------------------------------------------\n\n");
	
		while(!haltFlag){
			instr = NORM(RAM[Reg[PCINDEX]++]) ;
			opcode = OPCODE(instr) ;
			args = ARGS(instr) ;
			(*(INSTRS[opcode]))(args) ;
		}
		
		printf("\n\n-----------------------------------------------\n\n");

		if(DUMP){
		printf("Dump of RAM at time of halt:\n\n") ;
		printf("\tAddr\tHex\tBinary\n") ;
		printf("\t----\t---\t--------------\n\n") ;

		for (k=0 ; k<=j+1; k++){
			printf("\t%.4d\t", k) ;
			hbDump(RAM[k]) ;
			printf("\n") ;
		}

		printf("\n\t\t. . . . and all the rest are zeros.\n") ;
		printf("\n-----------------------------------------------\n\n");
		}
		
		while(c!='\n') scanf("%c",&c) ;
		if(rerunFlag) scanf("%c",&c) ;
		printf("Another run? (Y/N): ") ;
		scanf("%c",&c) ;
		printf("\n") ;
		runFlag = (c=='y' || c=='Y') ;
		while(c!='\n') scanf("%c",&c) ;
		if(runFlag){
			rerunFlag = 1 ;
			printf("Reload program? (Y/or use same): ") ;
			scanf("%c",&c) ;
			printf("\n") ;
			reloadFlag = (c=='y' || c=='Y') ;
			while(c!='\n') scanf("%c",&c) ;
			printf("--------------------------------\n\n");
		}
	}
}

/* ----------------------------- */
/* Hex and binary dump of an int */

int hbDump(int n){

		int k = WORDSIZE ;
		int i = 1 << k ;

		printf("%.3X\t", n) ;   /* Ooops: the "3" here depends on WORDSIZE */

		for( ; i>>=1, k--; i==0){

			printf("%d", (n&i)>>k) ;
			if(k%4==0) printf(" ") ;
		}

	}

/* ----------------------------------- */
/* END of PC231 simulator program file */
/* ----------------------------------- */