E.C.S.D. BASIC Interpreter Version 1D.


     To run the program type BASIC. The highest level in the interpreter
is the edit phase (The prompt is ':'). Any BASIC line can be typed (in
any order) at this point. Also valid are the commands RUN,LIST,SAVE,DUMP
,NODUMP,RESEQUENCE, & STOP
    Should the running BASIC program require data via an INPUT statement
the prompt is '?'.

     It is possible to interrupt the running program by hitting 'ESC'
and typing 'EXIT'.

     By typing 'BASIC(<file>)', BASIC statements will be read from
<file> and control returned to the console when <file> has been
exhausted. Commands, as above, are not accepted.

  Differences from 'standard' BASIC are as follows.

     A) Redimensioning in MAT instructions is not yet implemented

     B) Names of the form <letter><digit> can be used as list
        or table identifiers.

     C) RESEQUENCE <n> (default 10) resequences all line numbers
         and resets all jump destinations accordingly

     D) 'string' variables are not yet implemented

     E) It is possible to put more than one DIM statement per line
        E.G. 10 DIM A(3,5),B5(18)

     F) The 'LET' in a LET statement is optional

     G) To obtain  a variable dump (non zero values) on
        a runtime fault, type DUMP. To turn this off type NODUMP.

     H) Matrix inversion and transposition CAN be done in place.
        i.e. it is permissible to type    
               100 MAT A = INV(A)

     I) All 'unassigned' variables have the value zero.

     J) A restricted form of SAVE is available. The full format
         of the BASIC command is
               BASIC(<ifile>/<ofile1>,<ofile2>)
        <ifile>  is as described above. The file is presented as
                 initial input to the system.
        <ofile1> is an alternate output file. All messages and
                 output which normally goes to the console is written
                to this file. This should only be used when running
                a tested program.
        <ofile2> is the file which will receive the updated source
                when executing the command SAVE. The default is 
                <ifile>. SAVE with ofile2='.TT' has no effect.
                 E.G. to input BASIC statements to a file type
                       BASIC(/,<file>)
                 and, after typing in the program, type SAVE.

      Please report any abnormalities, suspected errors or general
complaints to me. Either directly or via Dr D. J. Rees or Mr
C. Whitfield.

             GOOD LUCK!
ALAN PATERSON
ROOM 1418,J.C.M.B.
7/5/75