The hp67u emulator shows a “0.00” before you get a chance to select debugging so how can you explore the HP-67’s startup code?
Fortunately there’s a way to start the hp67u in debug mode. You’ll see the power switch at ON but the display is off. It looks like this:
If you tap the display (for the menu) and then select Advanced you’ll see:
It’s pretty rare to see all zeros in the internal registers and microcode step 0.
From here you can turn logging on and see what happens at startup. I found it necessary to select [Step] first or the emulator starts the “Running…” process the instant you select [Log is ON] and you don’t get time to choose one of the more useful logging modes ([Log is DETAILED] or [Log is SMART]).
Here’s what happens:
67-startup.txt
