This is subproject of my ECM-16/TTL homebrew computer main project, where its assembly language is described.
Main part of the language is mnemonics, which directly translate to machine code instructions.
There are also aliases that are convenient substitutes for some instructions, or frequently used instruction sequences.
The directives are for assembler to be able to understand program origin and ending, data types and assignment.
The labels are useful for indicating addresses of specific instructions and variables, without the need to manually calculate them.
The assembler program is published on GitHub, there are releases for Ubuntu and Windows.