In the middle of all this, what Apple chooses to focus on is to implement a redesign that no one asked for, that butchers both the most conceivably fundamental usability and the visual pleasantness its user base has self-selected its platforms for; which only saving grace is that it is half-assed enough to not actually really change some things too badly, compared to what it could have been like. Although, had I upgraded to macOS Tahoe, chances are on top of the visual change, I would have been treated to basic Apple Event infrastructure falling apart and stopping working causing hangs, instability and unpredictability.
Real-mode programs freely execute CLI and STI to control interrupts, PUSHF and POPF to manipulate flags, INT n for DOS and BIOS calls, and IN/OUT for hardware I/O. In normal protected mode, these instructions are privilege-checked -- they execute normally if the caller has sufficient privilege, and fault otherwise. The 386 can't simply let V86 tasks execute them freely -- a DOS program disabling interrupts would bring down the whole system -- but trapping on every INT 21h call would make V86 impractically slow.
。WPS官方版本下载对此有专业解读
if char == 3: # CTRL-C
--verbose # invalid!