An open-access computer science learning hub, networking architecture reference, and hardware engineering portfolio maintained by Jack Sandoval.
Educational study modules covering fundamental network engineering, Linux system administration, and discrete mathematics.
The Open Systems Interconnection (OSI) model standardizes telecommunication functions into seven logical layers. Data transmitted across a network undergoes encapsulation as it travels down the stack from Layer 7 (Application) through Layer 4 (Transport: TCP/UDP), Layer 3 (Network: IPv4/IPv6 routing), and Layers 2 & 1 (Data Link MAC switching & Physical transmission).
Personal builds, infrastructure deployments, and software engineering projects.
Friends, mentors and people worth recognizing. A portrait, a name, and a line about why they are on the wall.
Curated systems engineering, networking, and classic internet memes.
Copy-ready commands for networking, web servers and Linux administration.
Plain-language definitions of the terms used across the reference library.
Standards documents and documentation worth bookmarking.
Small calculators that run entirely in your browser. Nothing is sent to the server.
Estimates assume an otherwise idle link and ignore protocol overhead.
Check what this browser can do, and test the hardware it exposes: microphone, camera, MIDI, location, motion sensors and download speed.
Everything on this page runs inside your own browser tab. Microphone audio, camera video, sensor readings, MIDI messages and your location are handled locally by your browser and are never uploaded, stored or logged by SandoSys. The server does one thing only: it hands you this page.
Your browser will ask for each permission separately, and only after you press a test button. Decline anything you are unsure about, and you can revoke a permission at any time in your browser's site settings. Nothing is recorded.
You will only see this notice once per browser session.
Requests audio access and shows a live input level so you can confirm the mic works.
Requests video access and shows a local preview. No frames are captured or saved.
Lists connected MIDI inputs and shows the last note message it receives.
Asks once for an approximate position so you can confirm geolocation works.
Live accelerometer and rotation readings, where the device provides them.
Fetches a small file from this site three times and reports the average throughput.
These APIs need a secure page (HTTPS or localhost), which this site is. Leaving this tab stops any running stream.
Connect with Jack Sandoval and SandoSys Labs across official channels.
One animated button, one public counter. Every press from every visitor lands on the same number.
times pressed by visitors
Counted on the server, so clearing your browser or opening a private tab won't reset it.
Authorized personnel only. Protected by SHA-256 cryptographic verification and automated brute-force lockout protection.