Back in the late 70's I was loading HEX values into 2708 EPROMS directly with a home made programmer to make programs for the 8039.
I still write code with a 100 MHz computer using an old DOS program called Vedit. And assemble it with AVMAC, another old DOS program.
I use an old EMP20 programmer to load the code into ATMEL chips these days.

I have done over 100 designs using just those tools and Ohms law.

To this day I am still self taught. Building on what I know and am comfortable with. When I went to school it was all tube theory and the calculator had not been invented yet. I still own a K&E Post Versalog slide rule.

I would like to move up to more modern programming tools but there are so many choices and I am not financially able to make a mistake and choose the wrong system tools for my 3 GHz computer. Which I put together myself.

If someone can suggest a universal programmer - including EPROMS - and a assembler and editor that will be around for a while I sure would appreciate it.