Example assembly code for the 8088/8080 to demo user/gpio LED's
This site contains a few examples for the v20-mbc SBC computer as detailed here: https://hackaday.io/project/170924-v20-mbc-a-v20-8088-8080-cpu-homebrew-computer
And here is an outline article showing how to use the programs. https://www.instructables.com/V20-MBC-Assembly-Language-Programs/
The .a86 versions are for 8088/86 cp/m-86 OS and the .cmd are executable versions.
The .asm versions are for 8080 cp/m-2.2 OS and the .com are executable versions.