ZEsarUX is an open-source multiplatform emulator that has positioned itself as one of the most powerful and versatile preservation tools created in Spain. Developed by César Hernández Bañó, this emulator broke the barriers of the ZX Spectrum to become a "multi-machine" system that, from its most recent versions (10.x to 12.x), offers robust and precise support for the Amstrad PCW series.

Unlike other more rigid emulators, ZEsarUX stands out for its "ZX Desktop" interface, its own desktop environment within the emulator that allows opening multiple tool windows simultaneously. For the PCW user, this translates into an unparalleled diagnostic and system control capability, allowing the monitoring of the Z80 CPU status while running CP/M or LocoScript.

Among its greatest documented contributions to the PCW system are:

• Disk Emulation Precision: It has integrated a deep rewrite of the uPD765 controller, achieving the loading of software with complex protections and non-standard disk formats that previously caused problems in other emulators.


• True Multiplatform Approach: It is the reference emulator for non-Windows system users. Its excellent performance on Raspberry Pi makes it the preferred choice for those who want to set up dedicated PCW workstations on low-cost modern hardware.


• Power for Developers: It includes an extremely advanced debugger, with the ability to view registers, real-time disassembly, and breakpoint management, facilitating the creation of new software for PCW directly from modern systems.

Official PCW support was prominently introduced in version 10.3 (released in May 2023) and has been maintained and perfected in subsequent versions, such as 12.1 (September 2025).

• Supported Models: Faithfully emulates the PCW 8256 and PCW 8512.
• Disk Emulation: Includes a complete rewrite of the 3" floppy disk emulation layer (uPD765), achieving the near-perfect precision necessary to load CP/M and LocoScript.
• Visual Floppy: Incorporates a visual feature that allows seeing disk drive activity in real-time, similar to the physical LEDs of the original drives.
• DSK Management: Allows extracting files directly from .dsk images and obtaining detailed track and sector information.