Interesting, I was not aware of that feature. It appears to be a
hardware feature. works with control+ alt+ enter on my machine.
--Devin
On 12/11/2016 11:58 PM, Sam O'nella wrote:
  I'm not sure specifically on the z-160 but my
z-150 had it (iirc and it's been a while ctrl+alt+ins or ctrl+alt+enter) I think put
you in the diagnostic rom which had a debugger.
 Curiously though i dont know if that is a hardware function or a feature of zdos?
 -------- Original message --------From: Fred Cisin <cisin at xenosoft.com> Date:
12/11/16  6:59 PM  (GMT-06:00)
 Don't those machines have a debugging monitor in ROM?  (something that IBM
 does NOT)  Otherwise 
DEBUG.COM should work.