ZXSpectr

https://github.com/chernandezba/zxspectr

It's a ZX Spectrum emulator written entirely in Assembler. It runs under MS-DOS, and pretty well also in Windows and MS-DOS emulators, like Dosemu and Dosbox. It's the first emulating the Inves Spectrum + (a Spanish clone)

You can try a newer and better emulator, made also by me, for Unix systems (Linux, Mac, Raspberry Pi and others) and Windows here:

https://github.com/chernandezba/zesarux

Features:

Emulates 16k, 48k, Inves Spectrum +, Spectrum 128k (English and Spanish), Spectrum +2 (English, Spanish and French) and Spectrum +2A (English and Spanish)

MS-DOS, Windows console, or MS-DOS emulators (dosemu & dosbox)

Kempston joystick emulation

Real tape loading through soundblaster

Some screenshots:

Start Screen

Main Menu

Machine Selection

Load from Real Tape

Debug menu