Sigma16 is a computer architecture designed for research and teaching in computer systems. This application provides a complete environment for experimenting with the architecture, including an editor, assembler, linker, emulator, and an integrated development environment (IDE) with a graphical user interface.
Sigma16 is suitable for use in a first course on computer systems. No prior knowledge of computer architecture is required; the only prerequisite is some general experience with programming. But Sigma16 is not limited to beginners: by following through the documentation and examples, you will gain understanding of machine and assembly language, as well as intermediate and advanced programming techniques.
This is free software, available at https://github.com/jtod/Sigma16 under the GPL-3 license.
Sigma16 runs in a web browser: you don’t need to download or install anything. To launch the app, just visit the Sigma16 Home Page, https://jtod.github.io/home/Sigma16/, and Click to run Sigma16.
Sigma16 Version 3.8.x runs on current (2024) versions of the following browsers: Chrome, Edge, and Opera. It is not currently supported on Safari or Firefox.
It is also possible to download the software and run it locally, without Internet access. There are command line tools for running the assembler and linker in a shell, and the GUI can also be executed on a local machine. See the Installation section in the User Guide.
The running app displays the User Guide, which shows how to get started step by step. Just launch the app and follow the tutorials. You can also access the User Guide directly, without launching the app:
The app contains a collection of example programs. The User Guide begins with tutorials that introduce the system step by step, showing how the examples work, followed by a reference specification of the architecture, instruction set, and assembly language.
The examples include basic programming, compilation patterns, conditionals, loops, arrays, logic, bit manipulation, records, arithmetic on large natural numbers (“bignum”), modules, import and export, linking, relocation, pointers, lists, trees, graphs, concurrency, mutual exclusion, memory management, and threads and processes.
The architecture is designed to be simple enough for beginners to learn easily, yet flexible enough to support advanced programming techniques, including systems programming. This is a 16-bit architecture; all registers and memory locations are 16 bit words, and addresses are 16 bits.
A subset of the architecture called Core is suitable for elementary courses in computer systems. Core has 17 instructions, with some additional pseudoinstructions for convenience.
The full architecture, called Standard, has additional instructions for logic, bit fields, arithmetic on large natural numbers, and systems programming.
There is also a digital circuit, available separately, that implements the Core architecture. The circuit is specified at the level of logic gates and flip flops, and is expressed in Hydra, a functional computer hardware description language: https://github.com/jtod/Hydra. Hydra can simulate the circuit, so the example programs in the Core architecture can run on the circuit as well as the emulator.
The latest version is available on the Source Repository https://github.com/jtod/Sigma16.
The version number is given in the VERSION.txt file in the source
directory. It’s also given in the running app on the Welcome page,
the User Guide, and the Options page.
The architecture, implementation, circuits, documentation, and examples are designed and written by John O’Donnell, https://jtod.github.io/index.html.
- Copyright (C) 2024 John T. O’Donnell
- License: GNU GPL Version 3. The full text of the license is given in the source repository in Sigma16/LICENSE, as well as at https://www.gnu.org/licenses.
Sigma16 is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License version 3.
Sigma16 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 General Public License for more details.
You should have received a copy of the GNU General Public License along with Sigma16. If not, see https://www.gnu.org/licenses.