AmiCalc 1.3 is a Workbench/Intuition native scientific calculator built to bring the “big calculator” experience to any stock Kickstart 1.3 machine. The program recreates the tactile workflow of hardware calculators: button matrices render with Intuition primitives, menus expose constants and modes, and every keystroke updates a running expression so that results are transparent. The codebase serves two purposes—providing Amiga users with a lightweight yet capable calculator, and acting as an example of how to mix classic Intuition UI code with double-precision math on constrained hardware. This repository mirrors that intent by including both the full C sources and the Workbench icon/binary that can be dropped directly into a real or emulated setup.

• Compact Intuition UI (300x200 px) with dedicated clusters for scientific and numeric keys.
• Inv toggle that swaps between direct and inverse functions (sin/asin, cos/acos, tan/atan, ln/exp, log/10^x, sqrt/x^2, x^y/yth root, e^x/ln).
• Full arithmetic toolkit: +, -, *, /, x^y, e^x, Exp, sign change, %, n!, parentheses, and backspace.
• Constantes menu to inject pi or e at double precision.
• Modo menu that switches trigonometric functions between radians and degrees.
• Vista menu that toggles a live expression readout so you can confirm precedence and parentheses.
• Error readouts (ERR) whenever invalid inputs are detected (negative roots, non-integer factorials, overflow, division by zero, etc.).

• VBCC compiler accessible via vc or through the VBCC_ROOT environment variable.
• Amiga NDK 1.3 headers; set the NDK variable (defaults to $(HOME)/Amiga/NDK_1.3) or override NDK_INC to point at your installation.
• Standard Intuition and Graphics libraries present on the Amiga system where the binary will run.

1. Export VBCC_ROOT if vc is not already in your PATH:

   export VBCC_ROOT=/path/to/vbcc

2. (Optional) Target a different Kickstart flavor by passing TARGET (defaults to kick13):

   make TARGET=kick20

3. Build the project from the repo root:

   make

   The rule runs vc with the flags in Makefile and produces amicalc plus the accompanying amicalc.info.
4. Remove build artifacts with:

   make clean

1. Copy amicalc and amicalc.info to a directory on your Workbench volume (physical machine or emulator).
2. Launch from Workbench via double-click or from CLI (execute amicalc). A window titled AmiCalc 1.3 opens on the Workbench screen.
3. The layout is tuned for Kickstart/Workbench 1.3, but it also works on later versions as long as Intuition and Graphics libraries are available.

• Enter numbers with the keypad and press Exp to append an exponent for scientific notation (mantissa e exponent).
• C clears every register and expression, while <- deletes the last character.
• Pressing Inv flashes the INV prefix in expression view to remind you that the scientific keys now use their alternate behaviors. x^y combined with Inv calculates the y-th root of the left operand.
• % divides the current value by 100; n! computes factorials for integers 0 through 170.
• Trigonometric functions honor the RAD/DEG option selected in the Modo menu.
• Enable Vista → Expresion to see the algebraic string that is being evaluated in real time, which helps debug parentheses-heavy formulas.

• amicalc.c – complete calculator implementation including math core, Intuition drawing code, and menu handling.
• amicalc – prebuilt AmiCalc 1.3 binary ready to copy to Workbench.
• amicalc.info – Workbench icon for the executable.
• Makefile – VBCC/NDK build rules and overridable variables (TARGET, VBCC_ROOT, NDK, NDK_INC).

This project is distributed under the MIT License, enabling reuse, modification, and redistribution as long as attribution and copyright notices remain intact.