anchor.diff:  
   : read-inode ( inode# -- )
     1- inodes/group @ u/mod
  -  20 * group-descriptors @ +
  +  desc-size @ * group-descriptors @ +
     8 + l@-le               \ reads bg_inode_table_lo
     block-size @ *          \ # in group, inode table
     swap inode-size @ * + xlsplit seek drop  inode @ inode-size @ read drop
  
positive.code:      data @ 58 + w@-le inode-size !
    THEN
    data @ 20 + l@-le blocks-per-group !
  
    \ Read the group descriptor table:
    first-block @ 1+ block-size @ *
  
negative.code: 
  INSTANCE VARIABLE blocks-per-group
  INSTANCE VARIABLE group-descriptors
  INSTANCE VARIABLE desc-size
  
  : seek  s" seek" $call-parent ;
  : read  s" read" $call-parent ;
  