 


DIRTY.COM (DIRectory utiliTY)


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     This  program  enables  users  to 


perform advanced directory maintenance 


and  will also retrieve hidden "SYSTEM 


FILES"!





RUNNING DIRTY


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     When  the program is run you  are 


asked to select an option from a  list 


of seven.





Option  1.


---------- Global  erase.   This  will 


erase  all  current unerased files  on 


the  selected drive.    ALL the  files 


are  erased.  e.g.  locked and  system 


files  have no protection but  as  you 


will  see  from the next  option  this 


doesn't matter at all.





Option 2. 


--------- Global  unerase.  This  will 


unerase   all  erased  files  on   the 


selected   drive,    all   files   are 


retrieved  even  ones you thought  you 


had lost ages ago!  You may find  that 


certain  file  names appear more  than 


once,  this is correct as the  program 


looks at each extent in the directory. 


Each  extent is worth 16K (a one  byte 


program  will have its own extent)  so 


if  you have a program that is between 


16K  and  32K long you  will  see  the 


program  name  appear twice.  This  is 


handy   as   a  check   against   file 


corruption.  For example,  If you knew 


you had erased a program that was over 


16K (e.g.  22K) long and at some later 


date  you decide to retrieve  it,  you 


will expect to see the file name twice 


in the unerased file list, If there is 


only one then DOS has allocated one of 


your erased extents to something  else 


and the program will be useless.  This 


information  is not available once the 


file  has  been  erased.   So,  it  is 


impossible  to say how long a  program 


was,  unless the last extent is  still 


on  the  disc.  (improbable!) Then  by 


examining   the   allocation    blocks 


assigned  to  the extent some idea  of 


the   original   file  size   may   be 


obtained. Once a file has been erased, 


DOS    re-assigns   the   old    files 


allocation  blocks.  The point  being, 


Although  it may appear that you  have 


been able to retrieve an old file,  it 


doesn't  necessarily follow  that  the 


information contained within that file 


is  the original information.  If your 


knowledge  of the DOS is  limited  and 


you didn't follow the last part, don't 


worry.  If a program is over 16K long, 


DOS  hides the second entry from  you. 


DIRTY will show you the correct number 


of  entries  if the program  has  more 


than  one  extent,  When DOS erases  a 


file  it erases all entries so  as  to 


make  all  the  extents  available  to 


other data, if you then wish to enable 


an  erased  file  with more  than  one 


extent you must unerase all entries as 


they appear or when DOS comes to  load 


the program,  some of the program will 


be missing.  The opposite is of course 


true,   therefore   to  erase  a  file 


properly.  erase all entries (extents) 


from the directory.  You may find  you 


retrieve  files that crash as you  run 


them, this is because you are enabling 


an  incomplete file.  Always  remember 


that  an  erased file is fair game  to 


the disc operating system.  All  files 


are  guaranteed preserved unless  disc 


write  operations  take place or  have 


taken  place and an erased  extent  is 


allocated elsewhere.





Option 3. 


---------  Selective    erase.    This 


allows you to erase files selectively. 


Each file name on the designated drive 


will  appear with the question  "Erase 


Y  or  N" beside  it.  As  you  answer 


either Y or N the next file name found 


on  the disc is displayed for  similar 


treatment.





Option  4. 


---------- Selective unerase.  This is 


the same as option 3,  but in reverse. 


Both  options list and act upon locked 


and system files.  Option 4. shows you 


when  a  locked  or  system  file   is 


brought  back to the directory,  DIRTY 


also unlocks the file.  Again remember 


that  is unimportant whether or not  a 


file is/was locked,  if you erase  one 


by accident simply unerase it!





Option 5.


---------  DIR system files.  This one 


is a bit sneaky as it lists the system 


files  (erased  or not) on the  logged 


drive.   To  retrieve  a  system  file 


simply unerase it with option 4, or if 


the file isn't erased simply erase  it 


first using option 3. For example, you 


suspect a disc contains a system file, 


first  run 'DIRTY',  select option  5, 


this will list all the system files on 


disc,  it will also say if the file is 


erased or not (yes some people do hide 


system  files by erasing them!).  Lets 


presume  that the file  isn't  erased, 


note the file name, return to the main 


menu and select option 3. When you see 


your file name,  erase it.  Now select 


option  4 and unerase it.  It will now 


be unlocked,  in the directory and all 


yours!  Alternatively  you could  have 


done a global erase/unerase, this will 


have  the  same effect on  the  system 


file,  but  of  course,  will  unerase 


everything else it finds. Doing it the 


latter  way will also show  any  newly 


enabled   system  files  as  they  are 


unerased.





Option 6.


---------  DIR erased files. This will 


list  all  the  erased  files  on  the 


selected drive but will take no action 


upon them.  The total number of  files 


found during any operation is shown at 


the  end  of that operation as  a  hex 


figure.   This  is useful for  finding 


out  how  much  room is  taken  up  by 


erased files,  unerased files,  system 


files  etc....  The  program is  fully 


error  trapped,   this means  that  if 


say,  the FDC (floppy disc controller) 


detects  a fault,  nothing is lost and 


the  program and any trapped data  may 


be recovered. As as example try taking 


your disc out and selecting an  option 


from the menu...





Option 7.  


---------  Pressing 'X' will terminate 


the  program and pass control back  to 


the operating system.





NOTE


----  


1:  DIRTY refers to files and  extents 


as files.  2:  ALWAYS exit the program 


by  the  exit option in the  menu,  or 


permanent  damage may be done to  your 


disc data.


