Input Cards

All tenninal input is in the form of space delimited words. All normal floating point and fixed point formats are recognized (termed “field-free” format). Floating point numbers must be distinguished from integers by a decimal point or exponent. All actual communication with the computer should be made in lower case and character parameters are never enclosed in quotes.

Interactive Keyboard Commands

At the beginning of each cycle, the code checks for and executes commands that the user may have typed during the cycle. If it is in “stepping” mode (see the s command below), it acknowledges completion of the command with a “>” which serves as a prompt for the next command.

If the code is in normal running mode, command completion is acknowledged by an ‘ok’ and code execution continues. ‘Oops!’ is returned if the cominandcan’t be understood or if an argument has an inappropriate value, and code execution (or suspension) is continued. Interactive keyboard commands may be entered more than one to a line by using commas as delimiters. The resulting construct is termed a “keyboard message.” The keyboard message may be up to 80 characters long and may contain any possible number of comma-delimited command lines, which are executed sequentially. Except as noted below, words representing input character variables are truncated to 8 characters, whereas numerical input is “field-free,” except that floating point numbers must be distinguished from integers by a decimal point or exponent. The number of blank-delimited symbol(s)/word(s) in the current command line is limited to a maximum of 60. Allowed interactive keyboard commands are listed below.

Each command keyword is given in bold letters, followed by its arguments, if any, in italic capital letters. For the more complex commands, an example is given, which also serves to indicate the type of the arguments.


As indicated by the examples, actual communication with the computer should be made in lower case and that character parameters are never enclosed in quotes.

Resolution of Commands

The commands desribed in this section are processed by the ttycom subroutine and its entry point execute for KEPLER Generator Input Cards, BURN Generator Cards, and Command Files. If input processing is done by any of these latter, KEPLER first matches against commands local to these functions before passing execution to ttycom as described below.

Changed In Version >16.0.0.


Some of the commands originally were desined for special functions, e.g., “link” files that have now been generalized, and make no sense to use in isolation, i.e., some of them require several commands to yield a menaingful result, e.g., the pst card.

KEPLER first tries to match the input string against the listed commands. In case the commands starts with an integer or float variable, this implies the <j> command.

If no command is found that matches, KEPLER will also try to locate, in this sequence,

  1. Changable (‘P’) Parameters by name

  2. Edit (‘Q’) Parameters by name

  3. Used-Defind Optional (‘O’) Parameters by name

and in case these are found, then a command is executed as if p, q, or o had been specified (implcitly).

New In Version 17.0.2: automatic matching of names against p, q, and o parameters

Variable Replacement

You may specify an expression in curly braces to be replaced by the result of evaluating it, using the same procedure as outlined for command files.

p 38 {p 2}
p 38 {p 2*2.}

New In Version 17.0.12.

List of Input Commands


  • j, n, and m stand for integers corresponding to allowed zone number where n > m

  • IONSYM is the ASCII symbol for one of the ‘ions’ in the APPROX, ISE, or NSE networks

  • ISOSYM is the ASCII symbol for one of the isotopes in the current BURN coprocessor network

  • REACSYM is the ASCII symbol for the editable nuclear reaction rates.

See also

A detailed explanation of the edits that result from some of the commands is given in Zonal Edit Varlables.