Getting Started with MSX assembly. Is it necessary to have a MSX specific assembler?

Welcome to MSX.org, tap_ir!

NO. Just use the one that you prefer. Like one that runs on your development platform of choice, does a reliable job, supports all required features, and that you find easy to use.

Gen80 was my favorite back in the day, still good if you want to assemble some Z80 code on an MSX itself. For cross-development on PC or other, for example have a look at pasmo (hmm.. unmaintained?).

I also really recommend cross-development using a PC assembler, in combination with a version control system like Mercurial. You could use my assembler, Glass:

http://www.grauw.nl/projects/glass/

I created it after running into some Pasmo limitations wrt. program & output file addresses, in Pasmo they’re coupled unfortunately. Other assemblers were problematic for me because they were either not cross-platform (didn’t work on Mac) or used too much custom syntax like single-line repeat shorthands or the horrible write-multiple-instructions-on-a-single-line, which in my opinion makes the code harder to read rather than easier. I especially don’t like it when people use an assembler with a lot of custom syntax which is not available cross-platform (like Sjasm, TNIasm), because as a Mac user it essentially locks me out from contributing. So, this was my motivation to create Glass :).

Glass uses standard Z80 assembly syntax, is cross-platform, and has a selection of nice features without adding too much custom syntax. Especially accessing macro members as offsets, useful to build classes and structs, is a pretty novel feature that I use a lot. Also sections, used to direct code to different parts of the generated binary, I end up using frequently.

To see how I set up the build script you can look at the Makefiles 1 2 of my projects (I include the assembler in the repository for a convenient standalone checkout).

For generating COM, ROM or BIN files you can just include the headers in the assembly source, e.g. like so (example for ROM format), this applies to any assembler and this is also the reason you don’t need an MSX-specific assembler.