Hey, the IBMer who invented the ctrl-alt-del sequence for DOS has just retired, reported best at slashdot.
Dave didn't get the credit he deserves. He did a lot more, actually wrote the first BIOS for the IBM PC, which is the code that's hardwired into a PC to make it operate.
Also… we shared an office in IBM Boca Raton, right after I got outta school. I just wish I was smarter, and found a way to get onto the original PC team. Our department did an early PC we called ICON, but I didn't participate much.