Aucbvax.4284
fa.unix-wizards
utzoo!decvax!ucbvax!unix-wizards
Tue Oct  6 16:28:27 1981
Re:  TOPS-10 Interchange Backup Tapes
>From sdcarl!rusty@Berkeley Tue Oct  6 16:17:08 1981
This was written by Julius Smith last summer
to read a DUMP format tape written on Stanford's
Sail system. It is a quick-and-dirty but worked.

# include <stdio.h>

# define NIN 512*5
# define NOUT 512*5

char mt[] = "/dev/nrmt0";

main(argc, argv)
char **argv; 
{
	char t[NOUT],c[NIN];
	register char *pt, *pc;
	register int fid;
	register int i, j;

	if ((fid = open(mt, 0)) == -1) { 
		perror(mt); 
		exit(1); 
	}

	while (read(fid, &c[0], NIN) > 0) {
		for(j = 0; j < 512; j++) {
			pt = &t[5*j]; 
			pc = &c[5*j];
# ifdef DEBUG
			for (i = 0; i < 5; i++)
				printf(" byte %d is %o\n", i, *(pc+i));
# endif DEBUG
			for (i = 0; i < 5; i++) { 
# ifdef DEBUG
				printf("byte %d is %o", i, *pc);
# endif DEBUG
				*pt = (*pc >> (i+1)) & (0177 >> i);
# ifdef DEBUG
				printf(" -> %o\n", *pt);
# endif DEBUG
				*pt++ |= (*(pc++ -1) << (7-i)) & 0177;
			}
			*(pt-1) |= ((*(pc-1) >> 1) & 07); 
		}
		*pt = '\n'; 
		printf("%s", t);
	}

}