#include "pdp11.h" /* * KW11-L line time clock */ static word lks; static Interrupt cintr; static wordkwlread(u32int addr, int type){	switch(addr&~01){	case 0777546:		return GETVAL(lks, addr, type);	default:		print("can't read from %uo\n", addr);		return 0;	}} static voidkwlwrite(u32int addr, word val, int type){	switch(addr&~01){	case 0777546:		lks = SETVAL(lks, val, addr, type);		break;	default:		print("can't write to %uo\n", addr);	}} static voidclockproc(void *a){	int i;	Channel *c;	c = a;	for(i = 0; ; i++){		/* tick at 60Hz */		if(i == 2){			i = 0;			sleep(17);		}else			sleep(16);		lks |= 0200;		sendul(c, 1);	}} static voidclockthread(void *){	Channel *c;	c = chancreate(sizeof(ulong), 5);	proccreate(clockproc, c, mainstacksize);	for(;;){		recvul(c);		if((lks & 0300) == 0300)			reqintr(&cintr);	}} voidclockreset(void){	lks = 0200;} voidclockinit(void){	cintr = (Interrupt){ 6, 0100, 0, nil };	ioreadtbl[ADDRTOIDX(0777546)] = kwlread;	iowritetbl[ADDRTOIDX(0777546)] = kwlwrite;	threadcreate(clockthread, nil, mainstacksize);	clockreset();}