RPN-34 CE — Extending the HP-34C

What's been added in RPN-34 CE

For its price ($150 in 1979), the HP-34C was a remarkable calculator. It was the first pocket calculator to offer integration and root finding. Also, for the first time on an HP calculator, the factorial function could be applied to non-integer numbers.

RPN-34 CE enhances the HP-34C in many ways:



Register Arithmetic

For STO operations only
RCL ∑+ only

For both STO and RCL operations. Includes double-register ∑+ (R1 and R3) working with stack registers X and Y.
Addressing of registers R.0…R.9 Indirectly via I register only Directly, incl. arithmetic
Registers R20…R99 Not available Enabled in Settings.
Addressed indirectly via register I.
If enabled, register I is separate, not R20.
P≷S Not available Swap primary and secondary registers
Availability Shared with program memory; no registers at max. program memory size All registers available at all times.
Hyperbolics Not available SINH, COSH, TANH and inverse
ATAN2 Not available Quadrant-preserving atan(x)
LOGy Not available Base y log of x
LN x! Not available Logarithm of factorial of x
RND Not available Round x to displayed value
MOD Not available Remainder of y/x
ODD Not available Return 1 if x is odd
DIV Not available Return integer part of y/x in x, remainder in y.
CSGN Not available Generalised sign of x
NOP Not available No operation
ERRU Not available Programmed error stop
TIME Not available Current time in H.MS format
RAND Not available Create random number
MIN Not available Return lesser of x and y in x
INCR, DECR Not available Increment/Decrement x
BEEP Not available Produce sound (0…9)
EXMNT Not available Return mantissa and exp of x
SEPx Not available Returns fractional and integer part of x
CMAG Not available Change magnitude of y by x
F?, SF, CF Flags 0…3 only Flags 0…9
x≷ Not available Exchange x with any main register
x≥y, x<y, x≥0, x≤0 Not available Yes
(see also "Top Functions" at right)
Program steps 70 with 20 registers available
210 with no registers available
999 with 100 registers available
Labels LBL 0…LBL 9, A, B LBL 0…LBL 9, A, B
Save, load, annotate, view, print, share programs Not available Yes
Prefix keys Active if pressed Active if pressed. Deactivated if pressed again. Indicators show state.
Register view Not available All basic registers shown on single screen including formatted display.
Run/Stop and single-step program without leaving register view.
Decimal Point,
Thousands separator

Fixed to "."
Thousands separator shown as comma

User-selectable representations
Trig Mode display


Trig modes RAD and GRD show up in display
Command display

Not available

In program mode or while single-stepping, current command is shown as text below display
Current step display

Not available

Current program step is shown below display
Program memory fill status

Not available

Red progress bar shows amount of program memory filled

Optional programming and Top Bar keys:

With f prefix key active:

With g prefix key active:

With h prefix key active:

      Getting data into RPN-34 CE
      You can preset RPN-34's registers with data created externally without having to type them in.
      Simply prepare the data in text format in any app that can handle text, like Notes, Mail and many others.
      The data format looks like this:
      Rn or R.n value (where n = 0…9)
To set R1 = 4.5, R6 = 6.28E-7, R.3 = 439, prepare your data like this:
      R1 4.5
R6 6.28e-7
R.3 439
      Select all of the text and paste.
Upper-/lower-case is ignored.
One or more blanks or tabs may follow the register number.
M may be used in place of R.
R.n may also be written as R1n, e.g. R.3 is the same as R13.
The order of the registers is irrelevant.
Unlisted registers are left untouched.

      Top Bar
      Descriptions of the extra functions added to RPN-34 are built into the app:
– Open Settings, either by double-tapping the display, or by tapping the wrench symbol (top left).
– Select Dim or On, then tap on Operations.
      Other Functions
      Some g-shifted functions are shown directly on the appropriate keys:

      Flags are numbered from 0 to 10.
Their state may be viewed in register view:
The register numbers display the state of same-numbered flags. If the flag is set, the number is highlighted.

Two flags, out of the 10 flags available, have special properties:
F7 and F8 are auto-cleared on test.
F8 is auto-set by numeric user input.
All flags are cleared by turning the calculator OFF.
      RPN-34, along with RPN-32 and RPN-38, are the only HP-simulators before the HP-15C to offer all 12 possible comparisons.
      Addressing Program Steps
      To quickly address any program step
in both RUN and PRGM modes:
Enter GTO + nnn
where nnn is the desired step (3 digits)

To address the first program step 000:
In both RUN and PRGM modes:
Enter g TOP or GTO + 000

In RUN mode only:
Enter h RTN or f PRGM

To address the last program step:
in both RUN and PRGM modes:
Enter g END
Enter GTO . .
      Branching via I-Register
      To branch to any label using the value stored in register I:

If I=0, branch to LBL 0
If I=1, branch to LBL 1
If I=10, branch to LBL A
If I=11, branch to LBL B

If I=12, branch to LBL .2
If I=13, branch to LBL .3
If I=19, branch to LBL .9

Note that branching to labels .0 and .1 via the I-register is not possible.

If I<0, branch to (positive) step number I.


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