It’s important to consider the power usage on the 5V line supplied by the ZX Spectrum, as the voltage regulator inside the ZX Spectrum has a limited maximum current. Some measurements: Current ZX Spectrum 48K without peripherals 0.40 A (max 1 A) ZX Spectrum 128K toastrack / +2 without peripherals 0.75 A (max 2A) ZX-HD with … Continue reading ZX Spectrum and interfaces power consumption