Example
Basic RPN arithmetic
12 ENTER 3 x
Push 12, duplicate it into the stack, then multiply by 3 for an immediate 36.
RP12C
A modern RPN finance calculator for the web.
Inspired by classic desk-finance tools
Precision math with a little ceremony.
RP12C brings the calm, tactile rhythm of RPN to a premium browser experience. It is fast, local-first, keyboard-friendly, and built to feel like an instrument rather than a widget.
4-level stack
Calendar + simple interest
TVM + NPV/IRR + stats
Reverse Polish
Ready
ready
mdy
end
X Register
0
t
0
z
0
y
0
x
0
Calculator Face
The main deck now behaves like a shifted instrument: tap `f` or `g`, then your next key. Amber legends skew setup and finance. Blue legends lean toward analysis and alternate workflows.
keyboard: f / g / enter / opsshift: none
Full-guide controls
Mapped from the HP 12c user guide sections on stack, percent, math, and finance registers.
Stack
Core HP12C stack movement and recovery.
Percent
Direct percent, percent difference, and percent of total.
Math
Book I single-number and power functions.
Finance
Register utilities from the full user guide.
Programming
Stored-keystroke mode with line memory, `R/S`, single-step, back-step, clear, and `GTO` navigation.
runline 00
00
R/S halt
No instructions stored yet. Enter PRGM and tap keys to record.
Modes
Date format
Payment mode
Calendar
Run from the face with `f + 4` for DATE or `f + 5` for date difference after placing the inputs in Y and X.
Example: `4.072004` in M.DY or `7.042004` in D.MY.
Start
--
End
--
Actual Days
--
30/360 Days
--
Weekday
--
Mode
--
Simple Interest
Use `n = days`, `i = annual rate`, and `PV = principal`, then run from the face with `f + ENTER`.
Interest 360
--
Interest 365
--
Total 360
--
Total 365
--
Amortization
Set `i`, `PV`, `PMT`, place the payment count in X, then run from the face with `f + 1` or `f + n`.
Payments
--
Interest
--
Principal
--
Balance
--
Total Amortized
--
Mode
end
Discounted Cash Flow
Put amount in X, store `CF0` once, then add each next `CFj`. Set `Nj` from X when a cash flow repeats.
Run `NPV` with `f + 2` and `IRR` with `f + 3`. Use the buttons above here mainly for cash-flow maintenance.
Stored CFj
0
NPV
--
IRR
--
Rate i
--
No cash flows stored yet.
Bonds
Put settlement in Y and maturity in X, then run `PRICE` from `f + PV` or `YIELD` from `f + PMT`.
Price
--
Yield
--
Accrued
--
Total
--
Settlement
--
Maturity
--
Depreciation
Use `PV = cost`, `FV = salvage`, `n = life`, `i = factor` for DB, then run `SL`, `SOYD`, or `DB` from the shifted face.
Method
--
Year
--
Depreciation
--
Remaining Depreciable
--
Remaining Book
--
Statistics
Accumulate from the face with `g + 4` and `g + 5`, then run the shifted stats functions from the main keypad. This panel is now primarily a live register/result view.
n
0
Mean X
--
Mean Y
--
Std Dev X
--
Std Dev Y
--
Predicted X
--
Predicted Y
--
Weighted Mean
--
Correlation
--
Example
Fast percentage work
200 ENTER 15 %
Treat the second value as a percent of the first and keep your workflow in stack form.
Example
Guide-backed function set
DATE, AMORT, NPV, IRR, PRICE, DB, Sigma+
The emulator now tracks more of the user guide core, including calendar workflows, amortization, discounted cash flow analysis, bond math, depreciation, statistics, stack controls, and the main TVM register workflow.