               !SciCalc Version 0.48 (08-Jul-93)
               =================================

SciCalc is a scientific calculator which runs under 
the RISC OS desktop. It offers 4 numeric bases, 
3 trigonometric modes, a memory and a single level 
of brackets.  Its accuracy is limited to that of 
BASIC 64, which it requires to run. Input can be 
performed using the mouse and the keyboard.

Numeric range:
-------------

  Decimal     - Real values,  -9.9E99 to 9.9E99 entry,
                  -9.9E307 to 9.9E307 displayable
  Binary      - 32bit signed, 10000000000000000000000000000000 to
                  11111111111111111111111111111111
  Octal       - 32bit signed  20000000000 to 17777777777 
  Hexadecimal - 32bit signed, 80000000 to 7FFFFFFF

Accuracy:
-------- 
                                 
  Mode           Accuracy          Number of digits displayed
  ====           ========          ==========================

  Binary         Absolute                      32
  Octal          Absolute                   10 - 11
  Hexadecimal    Absolute                      8
  Decimal        64 bit FP         10 or 10 + 2 digit exponent

  Note:  real number underflow is not trapped.

Keys in decimal base:
-------------------- 

  Calculator        Keyboard           Function
  ==========        ========           ========

  0..9              0..9               numbers
  +, -, x, , =,    +, -, *, /, =      standard operators
                    Return, Enter      same as =
                   #                  change sign on number or exponent
  Exp               E                  allows entry of exponent
  .                 .                  decimal point
  10x, LOG, LN, eX                     exponential and logarithmic functions
  nCr                                  combination
  nPr                                  permutation
  ()                (, )               brackets (one level only)
  TT                                   the number Pi
  RND                                  random number between 0.0 and 1.0
  NOT, AND, OR, EOR                    logical functions
  %                 %                  percentage
  HYP (followed by trig fn)            hyperbolic functions
  SIN, COS, TAN                        trigonometric functions
  ASN, ACS, ATN                        inverse trigonometric functions
  x!                !                  factorial
  x                                   square root
  yx                                  Yth root of X
  x                                   square
  xY                ^                  X raised to the power Y
  1/x                                  reciprocal
  C                 Delete             clear calculation
  CE                                   clear current number only
  MC                                   clear memory
  Min                                  memory in
  MR                                   memory recall
  Mode                                 select radians/degrees/gradians
  Base                                 select decimal/binary/octal/
                                       hexadecimal base

Alternative keys in non-decimal bases:
-------------------------------------

  NAND                                 NOT AND
  NOR                                  NOT OR
  EQV                                  NOT EOR (equivalence)
  <O , O>                              rotate left or right
  <<< , >>>                            logical shift left or right
  << , >>                              arithmetic shift left or right
  DIV                                  integer division
  MOD                                  modulus (integer remainder)
  A - F             A - F              hexadecimal base digits

Using the percentage key:
------------------------

  47.3 + 15 % =                      to 47.3 add 15% of itself

  15 % * 47.3 =                      find 15% of 47.3

Operator precedence:
-------------------

Operators are evaluated in the following order of precedence
(highest shown first).

  unary operators
  yx
  xY
  nCr, nPr
  *, /, DIV, MOD
  +, -
  <O, O>, <<, >>, <<<, >>>
  AND, NAND
  OR, EOR, NOR, EQV

The SciCalc window
==================

The title bar indicates the current base and, for decimal, the current
trigonometric mode.  The SELECT and ADJUST buttons applied to the "Base"
and "Mode" keys cycle through the bases and modes in opposite directions.

The numeric display contains the most recently entered number or result.
Any errors, for example "Division by zero", are displayed here too.
To clear an error, use the "C" button.

Clicking in the numeric display turns the title bar a cream colour,
indicating that numbers and selected operators may be entered from
the keyboard.  When the title bar is grey, the keyboard does not affect
the state of SciCalc.

Note that changing from decimal to a non-decimal base will round the 
currently displayed value to the nearest integer, but has no effect on 
previous parts of the current calculation.  Rounding also occurs on numbers 
being recalled from memory in non-decimal bases.

Start-up options
================

Double-clicking on the !SciCalc icon in a directory viewer installs SciCalc
on the icon bar.  Clicking on this icon with SELECT or ADJUST opens the
calculator window.

You can optionally cause the window to be opened at a chosen place on the
screen when SciCalc is run, by setting the system variable SciCalc$Window,
for example:

*Set SciCalc$Window 700,900

The numbers are the x and y graphics coordinates for the bottom-left corner
of the displayed window.

You can also choose a particular base and trigonometric mode in which SciCalc
is to start, by setting SciCalc$Options, for example:

*Set SciCalc$Options 2,1

The first number specifies the base, the second the mode. Allowed values are:

  Base - 1  Decimal
         2  Binary
         3  Octal
         4  Hexadecimal

  Mode - 1  Radians
         2  Degrees
         3  Gradians

The above example sets the base to binary and the trigonometric mode (used 
when you next change to decimal base) to radians.  The default values are 
1,2 i.e. decimal and degrees.

Quitting from SciCalc
---------------------

You can quit completely from Scicalc by clicking MENU on the icon and
selecting Quit.  Alternatively, to remove the calculator window temporarily,
click on the window's close box.  Subsequently clicking on the icon will
re-open the window in the same position, with the calculation state 
preserved.

Requirements
------------

SciCalc will only run if the following modules have been loaded or can be 
found in the directory !System.Modules.

FPEmulator version 3.40 or later.
BASIC64 (BBC BASIC VI) 1.05 dated 19 Jan 1990 or later.
