I recently started working on some assembly code that I had not touched in a long time. The assembled code (.p file) was working. I relooked at the code, re-assembled it and it failed to work. A cursory look at the code does not show the problem.
As fast and small as assembly is, it can be difficult to troubleshoot. There is no easy way to add a print statement to output values. The disassembler in sz81 is helpful, but it goes too fast to see what is going on in the program. What I wanted was a tool that would let me step through the code, one line at a time, and see what is happening.
Luckily, Hot Z-II has been preserved. Written by Ray Kingsley in 1982, version 2 in available at the Internet Archive alone with the manual. I was able to download both and started reviewing the manual.