This project was implemented in Delphi 4 using Windows 98 around 2000 to 2004. It translates assembly source code into binary COM executables. You can learn more about COM executables at https://en.wikipedia.org/wiki/COM_file
If you want to create your own x86 assembler, you may find the 8086 instruction set.txt and FPU instruction set.txt files particularly interesting since they express how various opcodes, registers, and other operands can be assembled to corresponding binary. I created this data manually by reviewing official Intel instruction set architecture documents but you might save time by processing these files.
These files were shared with a website called planet-source-code.com which shut down in the decades since.
The following screenshot was taken while running the .com file assembled from Programs/Examples/Interrupts_and_more/I love Delphi.asm.
