2024-06-29 18:39:54 -04:00
|
|
|
# hamming
|
|
|
|
|
|
|
|
|
|
Copyright (C) Jonathan Lamothe <jonathan@jlamothe.net>
|
|
|
|
|
|
|
|
|
|
This program is free software: you can redistribute it and/or modify
|
|
|
|
|
it under the terms of the GNU Affero General Public License as
|
|
|
|
|
published by the Free Software Foundation, either version 3 of the
|
|
|
|
|
License, or (at your option) any later version.
|
|
|
|
|
|
|
|
|
|
This program is distributed in the hope that it will be useful, but
|
|
|
|
|
WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
|
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
|
|
|
Affero General Public License for more details.
|
|
|
|
|
|
|
|
|
|
You should have received a copy of the GNU Affero General Public
|
|
|
|
|
License along with this program. If not, see
|
|
|
|
|
<https://www.gnu.org/licenses/>.
|
|
|
|
|
|
2024-08-13 20:32:55 -04:00
|
|
|
## Executive Summary
|
2024-06-29 18:39:54 -04:00
|
|
|
|
2024-08-13 20:32:55 -04:00
|
|
|
This is an educational tool designed for experimentation with Hamming
|
|
|
|
|
codes. A hamming code consists of a certain number of data bits and a
|
|
|
|
|
smaller number of check bits. The data bits are used to store
|
|
|
|
|
information, and the check bits are used to verify the integrity of
|
|
|
|
|
the message as a whole. In the event of a single bit error, the code
|
|
|
|
|
provides enough information to restore the original message.
|
|
|
|
|
|
|
|
|
|
For more information on hamming codes, see [this
|
|
|
|
|
video](https://youtu.be/X8jsijhllIA) on YouTube.
|
|
|
|
|
|
|
|
|
|
## Installation
|
|
|
|
|
|
|
|
|
|
This program is written in [Haskell](https://haskell.org) using the
|
|
|
|
|
Stack package manager. The easiest way to install it is by first
|
|
|
|
|
installing [GHCup](https://www.haskell.org/ghcup/), and then from
|
|
|
|
|
within the project directory, run the command: `stack install`
|
|
|
|
|
|
|
|
|
|
You should then be able to run it by simply typing `hamming` on the
|
|
|
|
|
command line. There are currently no command-line options.
|
|
|
|
|
|
|
|
|
|
## Usage
|
|
|
|
|
|
|
|
|
|
When run, the program will display a 16-bit extended hamming code in a
|
|
|
|
|
4x4 grid. The rows and columns are numbered 0-3 and a green check
|
|
|
|
|
mark or red X will be displayed in the upper left hand corner of the
|
|
|
|
|
code indicating whether or not it's valid. The check bits will be
|
|
|
|
|
highlighted to make them more easily identifiable.
|
|
|
|
|
|
|
|
|
|
The program begins in display mode, but can be switched into edit mode
|
|
|
|
|
to change the value of the individual bits. While in edit mode, the
|
|
|
|
|
cursor will appear indicating the bit currently being edited.
|
|
|
|
|
|
|
|
|
|
## Keyboard Commands
|
|
|
|
|
|
|
|
|
|
In both modes of operation, these keys will have the following
|
|
|
|
|
effects:
|
|
|
|
|
|
|
|
|
|
- CTRL-C/Q: Quit the program.
|
|
|
|
|
- C: Set the check bits to reflect the values in the data bits.
|
|
|
|
|
- V: Correct to the nearest valid code (if possible).
|
|
|
|
|
- R: Reset the code to all zeroes.
|
|
|
|
|
|
|
|
|
|
### Display Mode
|
|
|
|
|
|
|
|
|
|
- E: Enter edit mode.
|
|
|
|
|
|
|
|
|
|
### Edit Mode
|
|
|
|
|
|
|
|
|
|
- ESC: Return to display mode.
|
|
|
|
|
- Up/K: Move the cursor up.
|
|
|
|
|
- Down/J: Move the cursor down.
|
|
|
|
|
- Left/H: Move the cursor left.
|
|
|
|
|
- Right/L: Move the cursor right.
|
|
|
|
|
- F: Flip the bit under the cursor (1 becomes 0; 0 becomes 1).
|
