Over the past few years, I have been recommending that Cemetechians looking to learn z80 ASM use the Doors CS 7 SDK to build their programs, even if they're not making Doors CS programs. The SDK includes a complete toolchain for assembling and linking assembly programs, and best of all, it works on Windows, Mac OS, and Linux with minimal effort. It was partially the result of a stream of confused potential ASM programmers who couldn't figure out why DevPac8x wouldn't work on their 64-bit computers, what was wrong with TASM, and similar complaints. Today, the command-line-driven process of using the Doors CS SDK gets even easier with Souvik1997's Doors CS SDK GUI.
This Windows program provides a GUI interface to the command-line based Doors CS SDK, making it very easy and fast to assemble and debug both simple and complex assembly programs. It lets you assemble programs with the touch of a button, load them into the WabbitEmu emulator, and test and debug them. Since it still requires the Doors CS SDK to work, it can even download the SDK for you and set it up on your computer, as well as grabbing the latest version of WabbitEmu. If discomfort with the command line has been stopping you from using the Doors CS SDK, or you just want a faster way to build your ASM programs on Windows, be sure to grab this.