71. Acorn DFS 0.90 and 1.20 (DNFS) workspace
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

** GENERAL ALLOCATION **

 Memory Locations  Function
 ~~~~~~~~~~~~~~~~  ~~~~~~~~
 &D00- DFF         General Workspace
 E00- EFF          Copy of Track-0 Sector-0 (with variations)
 F00- FFF          Copy of Track-0 Sector-1
 1000-10FF         General Workspace
 1100-11FF         Parameter Blocks for Files
 1200-12FF         1st File Buffer + SPOOL/EXEC
 1300-13FF         2nd File Buffer
 1400-14FF         3rd File Buffer
 1500-15FF         4th File Buffer
 1600-16FF         5th File Buffer
 1700-18FF         Further Workspace

 ** USEFUL LOCATIONS **

 {A} means ascii code   {N} means literal number

 &E00-E07 {A} First 8 bytes of disc Title, (see &F00-&F03).

 E08-E0E  {A} First Filename, (7 bytes, padded with spaces).

 E0F      {A} First Directory, (00 if same as current directory).
              NB: MSB of directory will be set if file is locked. You should
              AND this byte with 127 to get directory, and AND it with 128 to
              detect if it is locked.

 E10-E16  {A} Second Filename
 E17      {A} Second Directory

 E18-E1E  {A} Third Filename
 E1F      {A} Third Directory

 E20-E26  {A} Fourth Filename
 E27      {A} Fourth Directory

 etc..

 EF8-EFE  {A} Thirty-First Filename
 EFF      {A} Thirty-First Directory

 F00-F03  {A} Last  4 bytes of disc Title
              (If less than 12 characterss, title is terminated with 00 on
               0.90, but padded with spaces on 1.20.)

 F04      {N} Number of writes  to  the Catalogue.  (Hex number which appears
              after disc Title)

 F05      {N} Number of files on disc, multiplied by 8.

 F06      {N} !BOOT file *OPT4 Option number. (eg 3 for EXEC).

 0.90    1.20

 &10CA   &10C9  {A} Current Directory
  10CB    10CA  {N} Current Drive number

  10CC    10CB  {A} Library Directory
  10CD    10CC  {N} Library Drive number