beneath-apple-dos/D1S2/CH8.1#064000.txt

          Set the command index to -1 (none).
          Reset the pending command flag (none pending).
     9FD6 Add one to command index.
          If first charcater is a control-D, skip it.
          Flush to a non-blank (call A1A4).
          Compare command to command name in command name table
          at A884 for the current command index.
          If it doesn't match and if there are more entries
          left to check, go back to 9FD6.
          If it does match, go to A01B.
          Otherwise, if command was not found in the table, 
          check to see if the first character was a control-D.
          If so, go to A6C4 to print "SYNTAX ERROR".
          Otherwise, call A75B to reset the state and warmstart
          flag and go to 9F95 to echo the command and exit.
          (the command must be for BASIC, not DOS)
     A01B Compute an index into the operand table for the 
          command which was entered.
          Call A65E to see if a BASIC program is executing.
          If not, and the command is not a direct type command,
          (according to the operand table) go to A6D2 to print
          "NOT DIRECT COMMAND".
          Otherwise, if the command is RUN, make the prompt
          character ($33) non-printing.
          Check the operand table to see if a first filename
          is a legal operand for this command.
          If not, go to A0A0.
          Otherwise, clear the filename buffer (call A095).
          Flush to the next non-blank (call A1A4) and copy 
          the filename operand to the first filename buffer.
          Skip forward to a comma if one was not found yet.
          If a second filename is legal for this command, use
          the code above to copy it into the second filename
          buffer.
          Check both filenames to see if they are blank.
          If one was required by the command but not given,
          give a syntax error or pass it through to BASIC.
          (As in the case of LOAD with no operands)
          If all is well, go to A0D1 to continue.
     A095 A subroutine to blank both filename buffers.
     A0A0 Indicate no filename parsed.
          Check operand table to see if a positional operand
          is expected.
          If not, go to A0D1 to continue.
          Otherwise, call A1B9 to convert the numeric operand.
          If omitted, give syntax error.
          If number converted exceeds 16, give "RANGE ERROR"
          If number is supposed to be a slot number, give
          "RANGE ERROR" if it exceeds 7.
          If number is not a slot number, give "RANGE ERROR" if
          it is zero. (MAXFILES 0 is a no-no)
     A0D1 Set defaults for the keyword operands (V=0,L=0,B=0)
     A0E8 Get the line offset index and flush to the next
          non-blank, skipping any commas found.
          If we are not yet to the end of the line, go to A10C.
          Check to see if any keywords were given which were
          not allowed for this command.
          If not, go to A17A to process the command.
     A10C Lookup the keyword found on the command line in the
          table of valid keywords (A940)
          If not in table, give "SYNTAX ERROR" message.
          Get its bit position in the keywords-given flag.
          If the keyword does not have an operand value, go to
          A164.
          Otherwise, indicate keyword found in flag.
          Convert the numeric value associated with keyword.
          Give "SYNTAX ERROR" message if invalid.
          Check to see if the number is within the acceptable
          range as given in the keyword valid range table at
          A955.
          Save the value of the keyword in the keyword values
          table starting at AA66.
          Go parse the next keyword. go to A0E8.
     A164 Indicate C, I, or O keywords were parsed.
          Update the MON value in the keyword value table
          appropriately.
          Go parse the next keyword. go to A0E8.
.np
A17A-A17F Call A180 to process the command, then exit via echo
          at 9F83.
.np
A180-A192 Do command.
          Reset the video intercept state to zero.
          Clear the file manager parameter list.
          Using the command index, get the address of the 
          command handling routine from the command handler
          routine table at 9D1E and go to it.
          Command handler will exit to caller of this routine.
.np
A193-A1A3 Get next character on command line and check to see
          if it is a carriage return or a comma.
.np
A1A4-A1AD Flush command line characters until a non-blank is
          found.
.np
A1AE-A1B8 Clear the file manager parameter list at B5BA to 
          zeros.
.np
A1B9-A1D5 Convert numeric operand from command line. Call
          either A1D6 (decimal convert) or A203 (hex convert)
          depending upon the presence or lack thereof of a 
          dollar sign ($).
.np
A1D6-A202 Decimal convert subroutine.
.np
A203-A228 Hexadecimal convert subroutine.
.np
A229-A22D PR#n command handler.
          Load the parsed numeric value and exit via FE95 in
          the monitor ROM.
.np
A22E-A232 IN#n command handler.
          Load the parsed numeric value and exit via FE8B in
          the monitor ROM.
.np
A233-A23C MON command handler.
          Add new MON flags to old in AA5E and exit.
.np
A23D-A250 NOMON command handler.
          If C was given, put out a carriage return since this
          line was echoed but its CR was not.
          Turn off the proper bits in AA5E and exit.
.np
A251-A262 MAXFILES command handler.
          Turn off any EXEC file which is active.
          Close all open files (call A316).
          Set the new MAXFILES number at AA57.
          Go to A7D4 to rebuild the DOS file buffers and exit.
.np
A263-A270 DELETE command handler.
          Load the delete file manager opcode (05).
          Call the file manager open driver (A2AA) to perform
          the delete.
          Find the file buffer used to do the delete and free
          it (call A764).
          Exit to caller.
.np
A271-A274 LOCK command handler.
          Load the lock file manager opcode (07) and go to
          A277.
.np
A275-A27C UNLOCK command handler.
          Load the unlock file manager opcode (08).
     A277 Call the file manager open driver (A2AA) to perform
          the desired function.
          Exit to the caller via close (A2EA).
.np
A27D-A280 VERIFY command handler.
          Load the verify file manager opcode (0C) and go to
          A277 to perform function.
.np
A281-A297 RENAME command handler.
          Store address of second file name in file manager
          parameter list.
          Load the rename file manager opcode (09).
          Call the file manager driver at A2C8.
          Exit via close (A2EA).
.np
A298-A2A2 APPEND command handler.
          Call A2A3 to OPEN the file.
          Read the file byte by byte until a zero is found.
          If append flag is on, add one to record number
          and turn flag off.
          Exit via a call to POSITION.
.nx ch8.2