A comprehensive ZX Spectrum reimplementation for the Tang Nano 20K FPGA board, delivering authentic retro computing experience with modern enhancements.

• ZX Spectrum 48K - Switch with F2
• ZX Spectrum 128K - Switch with F1 (default)
• Pentagon 128 - Switch with F3

• Timex HiRes and HiColor - Toggle with Shift+F4 (enable) / F4 (disable)
• ULAplus - Toggle with Shift+F5 (enable) / F5 (disable)
• Display modes - Cycle through color → B&W → green → amber with F7
• Scanlines - Cycle interlacing options with F8

• SD card support via DivMMC / ESXDOS implementation
• Supported formats: TAP, TRD, SCL, and other ESXDOS-compatible formats

• TurboSound FM with dual YM2203 sound chips

• Video and Audio output via HDMI
• USB support for keyboard, joystick, and gamepad
• Kempston joystick emulation for USB joysticks

• F1 - ZX Spectrum 128K mode
• F2 - ZX Spectrum 48K mode
• F3 - Pentagon 128 mode
• F4 - Disable Timex HiRes/HiColor (default)
• Shift+F4 - Enable Timex HiRes/HiColor
• F5 - Disable ULAplus (default)
• Shift+F5 - Enable ULAplus
• F7 - Cycle display modes (color → B&W → green → amber)
• F8 - Cycle scanline modes
• F11 - Reset
• DEL - NMI (ESXDOS menu)

1. Flash the ROM file

   openFPGALoader --external-flash -o 0x300000 zx-nano.bin
   

   The binary includes ZX Spectrum 48, 128, ESXDOS, and TR-DOS ROMs.

2. Flash the bitstream

   openFPGALoader zx-nano.fs -f
   

3. Prepare SD card

   • Format as FAT32
   • Download and unpack ESXDOS from https://esxdos.org
   • Optional (but recommended) - download and unpack ESXDOS browser with long file name support from http://www.thefossilrecord.co.uk/author/bob_fossil_esq/ (direct link http://www.thefossilrecord.co.uk/wp-content/uploads/zx/BROWSE_latest.zip)

4. Install FPGA Companion

   • Follow instructions at https://github.com/MiSTle-Dev/FPGA-Companion
   • Supports both internal BL616 and external FPGA Companion (tested with M0S Dock)

• Tang Nano 20K FPGA board
• SD card (FAT32 formatted)
• USB keyboard
• Optional: USB joystick/gamepad
• HDMI display

Modern demo utilizing enhanced graphics modes

The ROM files included in this project contain software that is the property of their respective copyright holders.

This project is released under the MIT License. See the LICENSE file for details.

This project builds upon the work of several other projects and contributors:

• MiSTer FPGA - ZX Spectrum core
• Andy Karpov's projects - https://github.com/andykarpov
• Original ZX Spectrum implementation with enhancements for modern FPGA platforms

Special thanks to all contributors to the open-source FPGA and retro computing communities.