Entry System
ALG
and
RPN
entry modes are supported. If the prompt is "
>
" you are in ALG mode, if you have
0
at the
bottom of the screen, you are in RPN mode.
In RPN mode, the bottom line is the top of the stack. One per line and the top line is level 8. RPN mode has
an 8 level stack. Press
OPTN
to toggle between RPN and ALG mode. [
Todo: entry mode annunciator
]
Where it makes sense, the physical keys as labelled are used for their designated operation. So, for
example,
sin
enters
sin(
in ALG mode and performs
sine
on stack X in RPN.
The Reckon expression parser is relaxed about final closing parentheses. For example
sin(1
will be
accepted. Also
sin(sin(1
and for matrices
[[1,2][3,4
. This is a convenience feature. However, note that,
sin1
is not
sin(1)
but the variable
sin1
.
sin(1+
is not legal.
You can elide multiply in certain cases, immediately after a number and before a variable or function and
before parentheses. Examples:
2sin(1
,
2X
and
2(sin(1)+1).
This can be useful in RPN. e.g.
2X
can be
entered as part of usual number entry, also terms like
2π
.
Pi is bound to the π symbol (
SHIFT EXP
) and
also to the
Pi()
function.
The
SHIFT
key works in the usual way; press shift then another key for the shifted function. Do not hold
down shift. [
Todo: shift annunciator
]
The
ALPHA
key works in the usual way; press alpha then another key for its alpha character. Press
SHIFT
ALPHA
for
alpha lock
, disengage lock by pressing
ALPHA
,
EXE
or
AC
.
SHIFT ALPHA
whilst in alpha lock does
not unlock (same as Casio). [
Todo: alpha annunciator. shift + alpha for lower case
]. Pressing
SHIFT
whilst in
alpha, either immediately after the
ALPHA
key or in alpha lock allows the entry of lower case letters.
As well as on
SHIFT +
,
X
is mapped onto the
X
θ
T
key. This works as a convenient way to enter the variable
X
without a shift key press.
Hexadecimal and binary integers can be entered by prefixing with
0X
(use the
X
key) and
0b
respectively.
This is a bit experimental because only number input is supported, and there is no way to display an answer
in hex or binary.
Pre-minus, i.e.
(-)
, is the same as operational minus,
–
, in ALG mode. There is no need for two keys. Note
that unary minus binds tighter so
–x^2
is
(−𝑥𝑥)
2
and not
−(𝑥𝑥
2
).
In RPN mode, pre-minus is like
+/–
during number entry. You begin entering a negative number with
(-)
and also for negative exponents. Pressing
–
in RPN always performs subtract, but
(-)
won't change the sign
of a number after entry, because it will begin a new number entry.
The change sign function (negate) is bound to the fraction key
Ab/c
. This will
+/–
in RPN or
Neg()
in ALG. Do
not use this during RPN number entry, use
(-)
to change sign.
Abs
is bound to
SHIFT Ab/c
. Abs performs
|𝑥𝑥|
when
x
is real. For complex
z
,
Abs(z)
is the modulus and for
matrix m,
Abs(m)
the determinant.
DEL
performs a single character backspace for entry correction.
ALPHA DEL
is also
DEL
(currently).
SHIFT DEL
(labelled
INS
) performs
X<>Y SWAP
in RPN.
The
arrow
key,
, which means assign-to in Casio, maps to
=
for convenience. In ALG you assign with
expression like
A=2
(with arrow or with
=
they are the same). In RPN you can use arrow a bit like
STO
, e.g.
23
EXE A
, to store 23 in
A
.
F
D
is mapped to
Flt()
the
to-float
converter. In ALG you can convert a rational to floating point with
F
D
e.g.
Flt(ans).
In RPN this is especially convenient for converting results (like large integers) to floats;
just press
F
D
. Pressing
F
D
again or with a float attempts to convert the float back to a fraction.
Factorial, the
!
operator, is not marked on the keyboard. Reckon maps it to
SHIFT 3
.
For convenience
[[
is mapped to
SHIFT 2
(i.e.
MAT
).
