[comp.sys.dec] LBN's versus head numbers,formula wanted

elsen@esat.kuleuven.ac.be (12/11/89)

   I would like to know how LBN's relate to head numbers on RA81's and
RA90's.

This would give me the opportunity of tracking down possible defective heads
(or head pre-amplifiers) when I get BAD BLOCK Replacements in the errorlog
(of course , BBR's can have other causes too).

Could someone please post  this formula ?

-- 


  Marc Elsen (System Manager/Software Engineer)
  Katholieke Universiteit Leuven
  Dep. E.S.A.T.
  Kard. Mercierlaan 94
  3030 HEVERLEE
  Belgium
              tel. 32(0)16220931(ext. 1080)

               EMAIL : elsen@esat.kuleuven.ac.be

                       ...!kulcs!kulesat!elsen (UUCP)
                       elsen%kulesat.uucp@blekul60 (BITNET)
                       psi%02062166012::elsen  (PSI MAIL)

jtkohl@quicksilver.mit.edu (John T Kohl) (12/13/89)

Here's a program which reads LBN's from a Unix/Ultrix message file, and
translates to cylinder, etc.  This one knows about ra80's and ra81's; if
you get an RA90 user's manual, it should have the appropriate geometry
info you need to wire into this program.

I got this from someone else at MIT, who got it from someone else...
insert standard disclaimer.

#include <stdio.h>

#define LINESIZE 132	/* Maximum number of characters on a line */

main(argc,argv)
int argc;
char *argv[];
{
    char line[LINESIZE], *fgets(), *lineptr, *findstring();
    long blocknumber;
    FILE *infile;
    int nscyl, nstrk, nblk = -1;

    if (argc != 4) {
	fprintf(stderr, "Usage: %s drive_type drive_name log_file\n", argv[0]);
	exit(-1);
    }

    if (!strcmp(argv[1], "ra81")) {
	nscyl = 714;
	nstrk = 51;
	nblk = 891072;
    } else if (!strcmp(argv[1], "ra80")) {
	nscyl = 434;
	nstrk = 31;
	nblk = 242606;
    } else if (!strcmp(argv[1], "ra60")) {
	nscyl = 168;
	nstrk = 42;
	nblk = 400176;
    }

    if (nblk == -1) {
	fprintf(stderr, "%s: unknown drive type %s\n", argv[0], argv[1]);
	exit(-1);
    }

    if ((infile = fopen(argv[3], "r")) == NULL) {
	fprintf(stderr, "%s: Can't open %s\n", argv[0], argv[3]);
	exit(-1);
    }
    
    while (fgets(line, LINESIZE, infile) != NULL){
	/* Look for a line with the drive name and "hdr" on it */
	if ((findstring(argv[2], line) == NULL) ||
	    (lineptr = findstring("hdr 0x", line)) == NULL)
	    continue;

	/* Get the block number */
    	sscanf(lineptr, "%X", &blocknumber);
    	hdr(blocknumber, nscyl, nstrk, nblk);
    }
}

char *findstring(substring, string)
register char *substring, *string;
{
    register char *ptr;
    int match;

    for ( ; *string != '\0'; string++) {
	match = 1;
	for (ptr = substring; *ptr != '\0'; ptr++, string++) {
	    if (*ptr != *string){
		match = 0;
		break;
	    }
	}
	if (match)
	    return (string);
    }
    return (NULL);
}

hdr(blocknumber, nscyl, nstrk,nb)
long blocknumber;
int nscyl;
int nstrk;
int nb;
{
    long cyl;
    long trk;
    long sec;

    printf("hdr: %6D", blocknumber);
    if (blocknumber >=0 && blocknumber <=nb) {
	cyl = blocknumber / nscyl;
	trk = (blocknumber - (cyl * nscyl)) / nstrk;
	sec = blocknumber - (cyl * nscyl) - (trk * nstrk);
	
	printf(" cyl: %4D trk: %2D sec: %2D\n", cyl, trk, sec);
    }
    else printf(" Illegal blocknumber\n");
}

--
John Kohl <jtkohl@ATHENA.MIT.EDU> or <jtkohl@Kolvir.Brookline.MA.US>
Digital Equipment Corporation/Project Athena
(The above opinions are MINE.  Don't put my words in somebody else's mouth!)