It was slow so operating system devs didn't use it. So it was removed. Probably becouse hardware saved, properly, all registers and software can save only needed few (and sometimes miss something).
In effect: we don't know how secure it was...
But if it was good and Intel removed it then why Intel keeps so many useless crap in ?? Good parts - remove, bad - needed for backward compatibility... Can, finally, someone tell backward compatibility with WHAT ? DOS 4.0 ? Drivers for pre-winonly modems using plain ISA or PCI slots ??
Or maybe just like with EVE Online code (few years ago?) - no one anymore knows how some parts works...
In effect: we don't know how secure it was...
But if it was good and Intel removed it then why Intel keeps so many useless crap in ?? Good parts - remove, bad - needed for backward compatibility... Can, finally, someone tell backward compatibility with WHAT ? DOS 4.0 ? Drivers for pre-winonly modems using plain ISA or PCI slots ??
Or maybe just like with EVE Online code (few years ago?) - no one anymore knows how some parts works...