I was just trying out the example program 1 for SETERRORMODEQQ in the compiler documentation and it appears that no system prompt appears regardless of the setting of pmode.
This is with a console application (debug/x86) built with XE2015U1 run on Windows 10 Enterprise 1511 x64.
If it doesn't have an effect in modern versions of Windows, I would like to remove it to improve portability.
The sample in the User's guide will not produce the required failure to trigger the OS message about Abort, Retry, Ignore unless device B: in your system is one that's capable of generating that system prompt. Unless the system prompt is triggered the example programs can't demonstrate the functionality of SETERRORMODEQQ.
I was unable to synthesize the required prompt on my Windows 8 system with other devices I have/tried. I inquired w/Developers about an example that can demonstrate the routines functionality.
I believe this message still has relevance under newer OSes. I believe it may appear in a scenario where a hard-drive is unreadable, or perhaps a CD-ROM where the media is damaged and not readable.