ESPectrum vs JNEXT

ESPectrum is free, GPL-3.0 emulator firmware for Sinclair ZX Spectrum computers on Espressif ESP32 boards. It emulates Spectrum 48K, 128K, +2A, and Pentagon 128K systems, plus Microdigital TK90X and TK95 models. Supported boards include Lilygo TTGo VGA32 and Olimex ESP32-SBC-FabGL. Video output offers standard VGA, machine-rate VGA, and 15 kHz CRT modes in 16:9 or 4:3. Emulation includes the Z80, AY-3-8912 sound, beeper and microphone behavior, contended memory, and floating-bus effects. Users can connect PS/2 keyboards, joysticks, DB9 joysticks through a converter, and a PS/2 mouse acting as a Kempston mouse. It reads TAP, TZX, SNA, Z80, SP, TRD, and SCL files. Installation uses an online web flasher or release binaries. A FAT16- or FAT32-formatted micro SD card stores programs, disks, snapshots, and captures. PlatformIO builds are described for Windows, GNU/Linux, and MacOS/X.

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.