Command: fdrc

  FreeDOS Resident Calculator (FDRC) is a resident calculator for
  FDRC lacks following features:
  * Built-in help.
  * Fraction numbers support. (Perhaps fixed point 32:32 or (better)
    48:16 will be implemented in future versions.)
  * Functions like sin, cos, ln, etc.
  * Support for graphics and monochrome video modes.
  * Mouse support.
  FDRC has following features:
  * FDRC works with 32-bit integer numbers.
  * Expressions in reverse polish notation, eg:
    2 + 3 == 2 3 +
    2 - 9 + 8 * 5 == 2 9 - 8 5 * +
    (9 / (1 + 8)) * 5 == 9 1 8 + / 5 *
  * FDRC supports following operations:
    + -- addition              & -- bitwise AND
    - -- subtraction           | -- bitwise OR
    * -- multiplication        ^ -- bitwise XOR
    / -- division              < -- logical shift left
    % -- remainder             > -- logical shift right
    \ -- square root           { -- arithmetical shift left
    ˜ -- bitwise NOT           } -- arithmetical shift right
    ` -- negation
    Operations \, ˜ and ` -- unary: not(sqrt(123)+(-12)) == 123 \ 12 ` + ˜.
  * FDRC show result simultaneously in decimal, hexadecimal, binary
    and string format.
  * FDRC support numerous color video modes, including 40x12, 80x25,
    90x60, 132x25, 132x43.
  * FDRC work in resident and non-resident modes.
  * Color highlighting for different parts of result.
  * History.


  fdrc [options]


  Command line parameters:
  FDRC supports the following command line parameters (you can use '/'
  instead of '-'):
  -h         Short help.
  -?         Same as -h.
  -H         Help on keyboard and operators usage.
  -a         Calculate result after pressing any key, not only after
             pressing 'Enter'. Note: current string will be stored in
             history only after pressing 'Enter', even in this mode.
  -c         Clear input line when pressing any alpha-numeric key
             _immediately_ after popup. Pressing 'Delete', 'Backspace'
             or any such keys doesn't clear the input line.
  -e         Allow loading 2nd, 3rd,... copy of FDRC into memory.
  -n         non-resident mode.
  -w         Prevent loading FDRC into UMB. By default FDRC loads itself
             into UMB if it is available.
  -u         Unload. If INT 09h and/or INT 10h intercepted by other
             program, FDRC will print warning message and exit.
  -D         Temporarily disables FDRC.
  -E         Enables FDRC.
  -q         Quiet mode. If you try to call FDRC within graphics-mode
             program, FDRC will beep twice. If you reached 1st or last
             entry in history, FDRC will beep once. -q switch disables
             all such sounds.
  -l:number  Column of left side of FDRC's window.
  -t:number  Row of top side of FDRC's window.
             number -- decimal number >= 0.
  -k:number  Scancode of activation key (hexadecimal). See 'rbil_i09.txt'
             for details. Default value -- 35h ('/').
  -s:number  Code of shift keys (hexadecimal).
               Right Shift:  01
               Left Shift:   02
               Ctrl (any):   04
               Alt (any):    08
               Scroll Lock:  10
               Num Lock:     20
               Caps Lock:    40
               Insert:       80
               Default value -- 04 (Ctrl). For example: RightShift+Alt ==
               == 1 + 8 == 9.
  -y:number  Size of the history buffer (decimal). Default value -- 0.
             Minimal value is 200, maximal is 16000 (can be changed in


  Using FDRC:
  Type `fdrc' to run calculator. It will terminate and stay resident.
  Use Ctrl-/ to popup. You can change hot-key: see chapter Options -
  Command line parameters for details. Type `fdrc -n' to run calculator
  in non-resident mode.

  When FDRC is active, you can use some keys: see chapter Comments -
  Controls for details.
  Use input line to enter expressions. In expressions you can use hexa-
  decimal numbers (string of hex digits, w/o any prefixes or suffixes),
  decimal numbers (w/ suffix `.'), binary numbers (w/ suffix `@'), and
  strings (in double quotes, as in C).

  In the last line of FDRC's window you can see messages about errors:
  * Parse error -- displayed when parser encountered illegal character,
    such as `.' in the string `123ab87.' or `j' in `12j6'. Illegal
    character highlighted.
  * Stack not empty -- some numbers still on the stack after calculating
    result. I.e. there are too few operators.
  * Stack underflow -- there are too many operators in expression. Ope-
    rator, which attempted to pop numbers from the stack, highlighted.
  Last line also contains history indicator: number of current string
  and arrow. Arrow looks like diamond if there are no strings in the
  Up-arrow indicates that you can press Up key to get previous string,
  down-arrow -- you can press Down key to get next string, double-edged
  arrow -- you can press both Up and Down keys.
  After selecting required string by Up/Down keys you can edit it.
  Note that string in history buffer remains unchanged. You edit the
  copy of this string.

  You can use up to 10 registers for temporary results storage.
  Operator :x saves result in the register x, where x is digit in the
  range 0..9. Expression $x substitutes the value of the register x
  into whole expression. For example:
  123. 3 - :0  -- calculates 123 - 3 and saves result in the reg.0;
  29 :8 :9 12. * :1  -- calculates 29h * 12, 29h is saved in the regs 8
  and 9, the result saved in the reg.1; 7 $5 ^  -- calculates
  7 XOR reg.5.

  It is possible to calculate several expressions in the one line.
  In this case expressions are separated by semicolons. Result of the
  whole expression will be equal to the result of the last subex-
  Results of intermediate expressions can be stored in the registers
  and used later. For example:
  123. 3 - :0; 8; 89 9 - $0 * :4; af 67; 7 $0 ^ $4 |  --
  1) FDRC calculates 123 - 3h, result -> reg.0;
  2) calculates the value of the number 8;
  3) calculates (89h - 9h) * reg.0, result -> reg.4;
  4) _tries_ to calculate the value of the expression af 67, but this
  calculation fails due to missing operator, semicolon flushes stack
  of the evaluator, so this expression will be ignored;
  5) calculates (7 XOR reg.0) OR reg.4.

  You can use the following keys:
  Numerals and letters      -- enter numbers.
  " -- if you enter one double quote symbol, the second such symbol
    will be entered automatically.
  <-- and -->               -- move cursor. (right and left arrow key)
  Up and Down arrow keys    -- previous / next string from history.
  Page Up and Page down     -- first and last strings in the history.
  Home and End              -- move cursor.
  Enter     -- calculate result and store it into history buffer.
  Insert    -- toggle insert/overstrike mode.
  Backspace -- delete char before cursor.
  Delete    -- delete char under cursor.
  Ctrl-Y    -- clear string.
  Ctrl-K    -- clear text to the end of string.
  You can move FDRC's window using WordStar-like keys (by default):
    Ctrl-S -- left
    Ctrl-D -- right
    Ctrl-E -- up
    Ctrl-X -- down
  or Vi-like keys (if you defined VI_KEYS constant in
    Alt-H  -- left
    Alt-L  -- right
    Alt-K  -- up
    Alt-J  -- down
  Alt-S    -- switch between signed and unsigned decimal representation
              of result.
  Alt-D    -- stuff decimal representation of result to keyboard buffer
              and exit.
  Alt-H    -- stuff hexadecimal representation of result to keyboard
              buffer and exit.
  Alt-1 .. Alt-4 -- stuff corresponding part of binary representation
                    of result to keyboard buffer and exit.
  Esc      -- exit.
  For more information see: OR:
  FDRC is not part of the actual FreeDOS distribution.


  a) execute fdrc
  b) type CTRL-C to open UI
  c) type CTRL-S or CTRL-D or CTRL-E or CTRL-X to move it to the
     position that you want
  d) calculate 237 + 534 (decimal numbers):
     237. 534. + (ENTER)  You get the result 771d above (d=decimal)
  e) calculate 237 * 534 (decimal numbers):
     237. 534. * (ENTER) You get the result 126558d above (d=decimal)
  f) calculate 237 - 534 (decimal numbers)
     237. 534. - (ENTER) You get the result -297d above (d=decimal)
  g) calculate 237 : 534 (decimal numbers):
     237. 534. / (ENTER) You get the result 0d above (d=decimal) -
     not: 0.4438202 because it works with 32 bit integer.
  h) calculate square root of 25 or 35 or 36 (decimal numbers)
     25. \  OR: 35. \ give result 5.
     36. \ gives result 6.
     That's correct because 32-bit integers don't support fractional
  This is only a basic explanation! For more complex calculation options
  see above: Comments - Using FDRC. 

See also:


  Copyright © 2006-2007 Oleg O. Chukaev, help version 2023 W. Spiegl.
  This file is derived from the FreeDOS Spec Command HOWTO.
  See the file H2Cpying for copying conditions.