- Remember 8250 UART serial ports? Long dead.
Maybe 8250 chips have been superseded, but 8250 compatible ports continue to be available on many mainboards. And there's always USB adapters. And given how cheap a serial port is to implement, I'm sure we will continue to see it for at least service access to many devices going forward.
- Remember 2400bps modems? Long dead. How about accoustic couplers?
Again, V.22bis only modems are not sold anymore, but practically any modem that support V.92 will also support V.22 (and probably Bell 212 and even Bell 103 modes). And accoustic couplers do the same thing, but were motivated mostly by the insistence of Bell that you couldn't hook up your own equipment to the phone line directly. Until high-speed links get a better coverage, people in the boondocks will continue to rely on modems to get online.
- We had pensioned CGA and EGA - and gone for VGA by 1993. SVGA came soon afterwards.
But the VGA signal standard (plug, levels, etc.) has continued to work, and even fancy new 24" 1920x1200 monitors will display a 640x480@60Hz signal, just because creaky old BIOSes still start up with this or other equally outdated video modes.