JNEXT vs SpeccySE

JNEXT is a free, open-source emulator for ZX Spectrum software, with developer-oriented debugging and automation tools. It emulates 48K, 128K, +2A/+3, and ZX Spectrum Next Issue 2 machines. The debugger offers hardware views, registers, breakpoints, and backward execution; headless mode and deterministic screenshots support CI testing. Supported files include NEX, SNA, SZX, Z80, TAP, TZX, WAV, and RZX. Emulated audio includes three AY chips, a DAC, and a beeper, and supported peripherals include DivMMC, DMA, USB gamepads, and an ESP-01 WiFi module; networking is off by default. On first run, JNEXT can download the official NextZXOS SD-card image if none is configured. The original and working images together use about 2 GB of disk space. Packages are offered for Linux, Windows, and macOS under GPLv3. The project remains under development, and extreme cycle-exactness is not a goal. The Windows executable is not code-signed, and the macOS app is not notarized, affecting their first-launch warnings or blocking behavior.

SpeccySE has no write-up on Specifiction yet; its figures are above.