
                                                                             DISCED

               Form:           DISCED "TYPE"

               Purpose:        To examine and patch disc blocks.

               Author:         BJK MFR

               Specification:
                  Commands available:
               B n         Set logical block number base to n
               C n         Print n characters from current offset
               D n         Select disc drive n
               G [n]       Get block n from disc (default: current
                           block number)
               F [t]       Set disc type
                           [t] = F -> floppy disc
                                 K -> Cartridge disc ( cf. dk0: )
                                 P -> Big Disc Pack  ( cf. dp0: )
                           If [t] is not given then unit, drive,
                           etc. are reset to standard values.
               H name      Calculate hash value of name
               I           Print block information
               K           Check block checksum (& correct if wrong)
               L [lwb upb] Locate words which match Value under Mask
                           (lwb & upb restrict the search)
               M n         Set Mask (for L & N commands) to n
               N [lwb upb] Locate words which do not match Value
                           under Mask
               P n         Put block in store to block n on disc
                           (default: current block number)
               R           Print block number of Root Block
               Q           Quit (do not write to disc)
               S char      Set printing Style:
                           char = C -> characters
                                  S -> string
                                  O -> octal
                                  X -> hex
                                  D -> decimal
               T lwb upb   Type range of offsets in block
               U n         Set Unit (i.e. device) number to n
                           This is the absolute value of the
                           TRIPOS device number.


               V n         Set Value for L & N commands
               W           Windup (=PQ)
               X           Invert write protect state
               Y n         Set cYlinder base to n
               Z           Zero all words of buffer


















               number      Set current word offset in block
               =           Print values set in program
               / [n]       Print word at current offset
                           [or update value to n]
               'chars'     Put chars at current offset
               "chars"     Put string at current offset
                   Numbers can start with # or #X to indicate octal or hex.
               Strings can include BCPL string escapes (*N etc.).
                   The current block is that from the last G or P command.  It is
               the offset from the logical block number base.
               By default the disc type chosen by the command is for a floppy disc.
               However this may be specified explicitely in the command line by the
               letters f, k, or p as for the 'F' command.

               Example:        DISCED












                                                                          11.6.1981



