no$psx vs PCSX-Redux

no$psx is freeware for Windows that emulates and debugs PlayStation 1 and PSone software. It is intended to run without special video drivers, plug-ins, virtual CD-ROM drives, a system BIOS, or per-game configuration. Supported disc images include CCD+IMG, CDI, CUE+BIN, MDS+MDF, CHD, NRG, and ISO, alongside raw EXE files and ECM/CDZ decompression. Real CD-ROM drives require wnaspi32.dll, with the maker noting problems on Windows NT/2000 and later. Development tools include a disassembler, debugger, profiler, code and memory breakpoints, assembler, I/O map viewer, VRAM viewer, polygon viewer, TTY console, and PSX hardware specifications. The free BIOS clone may have compatibility issues; an original PSX-BIOS.ROM can be placed in the program folder. The maker says many games have not been tested and compatibility problems may occur. The listed v2.3 Windows 32-bit release adds pixel-accurate GPU rendering, texture/CLUT cache emulation, and timing reproduction. The plan price is free.

PCSX-Redux is a free collection of tools, research, hardware design, and libraries for PlayStation 1 development and reverse engineering, centered on a fork of the PCSX emulator. The project aims to replace the plugin system with a monolithic codebase using OpenGL3+ and ImGui. Debugging features include VRAM, MIPS, and SPU debuggers, save states, and a GDB server for controlling program execution from a compatible IDE. Users can also work with a Lua console and editor or connect to Ghidra 10.3 or newer for MIPS debugging and reverse engineering. Graphics options include software and OpenGL GPUs, filtering, true-colour rendering, MSAA, and wireframe or vertex polygon views. It supports Xbox controllers, digital and analog controller emulation, and PlayStation Mouse emulation. OpenBIOS provides a MIPS R3000A BIOS implementation that can boot games without a retail BIOS, although the listed system requirement says a BIOS is required. Downloads are listed for Windows Intel 64-bit, Linux Intel 64-bit AppImage, and macOS Arm. The project describes the codebase as usable but still needing cleanup before a first stable release, with experimental components.