CompTIA Exam Prep - ITF+, A+, Network+, Security+, CySA+

CompTIA SecurityX (CAS-005) doesn't stop at servers, laptops, and cloud workloads. Objective 3.5, "Secure specialized and legacy systems," asks candidates to think about the machines that keep the physical world running: the programmable logic controllers on a factory floor, the HVAC controller on a hospital roof, the medical infusion pump, and the decade-old embedded appliance nobody wants to touch because touching it might shut down a production line. These systems rarely get patched, rarely get replaced, and almost never get a security review — which is exactly why CAS-005 treats them as their own exam domain rather than folding them into general endpoint security. This guide walks through operational technology, embedded and IoT devices, the wireless technologies that connect them, and the specific security and privacy considerations CAS-005 expects you to apply when a system can't simply be hardened the way a modern server can. Operational Technology: SCADA, ...

A real-time operating system is not a fast operating system. It is a predictable one. The guarantee an RTOS makes is that a task will complete within a known time bound, every time — and it will sacrifice average throughput to keep that promise. A general-purpose operating system optimizes for overall responsiveness and fairness. If a task is occasionally delayed by 50 milliseconds while the system does something else, nobody notices. In an airbag controller, an infusion pump or a protection relay, that delay is the failure. Hard, Firm and Soft Hard real-time — missing a deadline is a system failure, potentially a catastrophic one. Flight control, engine management, medical devices, industrial safety interlocks. Firm real-time — a missed deadline makes that result useless, but the system continues. A dropped frame in a video pipeline. Soft real-time — a missed deadline degrades quality. Audio playback, most user interfaces. The exam distinction is...