Computing: Free Pascal Programming

Electronics: Binary subtractors simulation.

Download LogicGates4 desktop application (Windows 64bit) Download LogicGates4 source code (Lazarus/Free Pascal)

Description: Electronics related application, showing how logic gates can be used to design binary subtractors. The program is a simple interactive simulation of a 1-bit-half-subtractor, a 1-bit-full-subtractor, a 4-bit-full-subtractor and a 4-bit-adder-subtractor (the 2 last circuits being modifications of the 4-bit-full-adder, simulated in my LogicGames3 application), where the user can choose the circuit's input by opening/closing a switch, letting the current flow and observe the output as LEDs going on or off. To action the switches, just click on them. LEDs with solid color indicate high voltage, LEDs with a pattern color, low voltage.
A rather long document, intended for those, who aren't really familiar with binary numbers and binary arithmetic or with logic gates based electronic circuits, is available in the Help menu.

Change log:
Version 1.0 (February-March 2020): Original program.
Version 1.0.1 (September 2021):
    - Circuit drawing optimisation (proper display).
    - Spelling mistakes correction.

Free Pascal features: Combining images and shapes to create layouts. Interactively changing brush style and position of shapes. Using transparent images as "click-on areas". Using digits subscripts. Boolean operations (classic Pascal).


Electronics circuits: Binary adder-subtractor simulation