******›       DISKSAVR1.BAS DOCS!›       The program  is  on this  disk!›› Ever  copy a  disk only  to have  the› routine choke on ONE bad sector? Well› DiskSaver! is the  remedy!  Works  on› Sparta Sngl.  or Enh. Density.   Uses› direct    disk   access   thru   USR.› Allocates bad sectors in  bit-map  so› no  data  can  be  written  to  them.› Writes  to  the boot sectors so "DIR"› will show the correct amount of  free› sectors. Will  also  fix  disks  that› show freespace greater than the whole› disk. Ever  have  that happen? I hope› you  find  this routine useful. Watch› for a dbl density version on: The REM› lab. The WeB BBs 24hr 7 days 708-884-› 0315› * DiskSaver! v1.0 (c) 1990 by  REMlab› *************************************›     First things first.› I got to looking at the pile of disks› I  had  that  wouldn't format for one› reason   or   another   and   got  to› wondering just how  large  that  pile› was going to get before having to pay› extra rent. Then I started to  wonder› just why those disks wouldn't format.› Using a sector editor,  I  discovered› that  most  of  the  disks  had a bad› sector or two. Realizing that  a  box› of  "cheap"  disks cost as much as $6› retail, I would be throwing them away› to  the  tune  of over $20.00. Yes, I› had a pile of over thirty disks  that› wouldn't  format  correctly!  So,   I› decided to see if I could get ANY use› out of that pile.› I discovered that  I  could  fix  the› disks  using  a  sector  editor. This› required a great deal  of  typing  to› write  the  boot sectors the way they› were intended.› Then I discovered I  could  fool  the› editor  by  starting   off   with   a› properly    formatted   blank   disk,› reading the boot sectors,  one  at  a› time,  and  swapping  disks  to write› those  sectors  to  the  "bad"  disk.› Still   alot   of   typing  and  time› consuming too.  I  wanted  a  routine› that  I  could  just load and run and› let the machine do the work  like  it› was  intended to do. No problem, just› read the boot sectors of a good  disk› and  write  them to the bad one. It's› that easy. ›› WRONG!!!!!!!!› You can't read the boot sectors  like› you  would a read a file! And even if› you   could,   what   about  the  bad› sector/s? How  do  you  prevent  data› from  being written to those sectors?› I thought of creating  a  file  using› the  bad sectors. But, then how would› I get DOS to write the file to  those› particular  sectors  and  if the file› ever   got  accidentally  erased  how› could DOS be prevented  from  writing› data to those sectors? ›› Things  seemed  impossible  and I was› about to give up when I  was  messing› with  the  sector  editor  again  and› realized  I might be able to allocate› sectors without having  to  create  a› file  that  uses  those  sectors.  It› worked!  Now  I  had to find a way of› getting the machine  to  do  all  the› work  so  I  wouldn't have to use the› editor sector by sector. I found a 49› byte  USR  routine in a BASIC utility› package  I  had  laying  around  that› would  allow  direct  access  to  the› disk, one sector at a time,  and  any› sector on the disk.› Using  that  USR routine I could read› each sector except the bad ones and a› simple  error  trap would branch to a› line that would tell me which  sector› was bad.› Now  came the hard part, changing the› sector map so DOS would skip the  bad› sectors.  I  tried  and tried until I› discovered that the sector map allows› for  sector  0.  SECTOR   0   DOESN'T› EXIST!!!  But,  it's  in  the  sector› map!› Figure that one out! Okay, the sector› editor,   then   the   USR   routine,› allocate  the bad sectors, a bad disk› becomes a good disk, right?›› WRONG!!!!!!!!› I had a "fixed" disk and I started to› copy some files to that disk. I did a› "DIR" in the disk and guess  what  it› showed.  123  FREE SECTORS I tried to› copy one  more  file,  a  121  sector› file.›› ERROR  162!?  How  can  that  be? How› could I  be  so  dumb?  I  forgot  to› change  the  bytes  that tell you how› many free sectors are on the disk. Oh› well,  just  remember  that there are› fewer sectors  on  the  disk  than  a› "DIR" shows.›› WRONG!!!!!!!!› Finding   the   free   sector   bytes› required alot of trial and error. ie;› sector editor, change a byte, exit to› DOS,   "DIR",   wrong  bytes,  sector› editor, change a byte, back  to  DOS,› "DIR", wrong bytes, etc. etc....›› It  about  drove me nuts! Back to the› ol' drawing board? No! I only had  to› add  a  few  lines  that would keep a› count of the bad  sector  and  change› the  free sector bytes before writing› the boot sectors and  sector  map  to› the disk.›› So, here's beta-test version 1.› DiskSaver! by REMlab.› It loads from DOS with BASIC enabled.› Sorry, SpartaDos  3.2  only  in  this› version  and  no double density, yet.› (But, I'm still working on  it.  When› perfected,  it  will handle ALL DOSes› known  to the  Atari 8-bit [I hope].)› Before I forget, DiskSaver! has taken› up a large chunk of my time, and, I'm› not yet through with it. But, I still› gotta  eat!  Any  donations  will  be› gladly  accepted  and will be devoted› to writing more useful stuff  and  to› the running of my board.› If you feel the need, send it to:› REMlab  %  R.  Cook,  P.O.  Box  1144› Arlington Hts., IL, 60006-1144› Atari! Power without the price!    ›              **END**›