DTR timing

[stevech]

Don
Sorry to touch this area again, but...
This new computer of mine refuses to ID the ZX24a via the ethernet to serial bridge. The older computer was intermittent - some days OK, some not, for no good reason I could find.

So with this new one (the native serial port works fine), and the ethernet bridge, I did some testing by adding status displays to the ZLoad DLL source that you provided. In reading that source, I'm confused a bit and maybe you can explain...
The code in atn() multiplies period * duty, but duty is an integer rather than fraction less than one (e.g., 1 to 100%). The default period is 10mSec and the default duty is 1.

In another post here on this topic, I understood that DTR must toggle 3 or more times, where 20mSec <= period <= 50mSec (vs. the 10mSec I noted above). I also see that the IDE allows one to set the period < 20mSec. The duty cycle seems largely irrelevant because of the capacitor coupling to create a pulse, but duty cycle may be important to certain devices like ethernet bridges, so the default in the IDE might best be 50% or so.

Maybe a scope photo or two?

In addition to fiddling with wrote a visual basic 6 program that toggles DTR using the Windows functions