> and I discovered in the (DR-DOS based) BIOS at one point that the serial port's electrical behavior can be customized between being edge triggered or level triggered.
Things like that make John Titor's IBM 5100 story slightly more believable. Old computers often have strange features which are omitted from their successors due to being rarely used (for instance, the original IBM PC could use current loop on its serial port connector). One could imagine someone with access to a time machine taking a short trip to the past just to grab one of these old computers as a replacement for a failed one.
Things like that make John Titor's IBM 5100 story slightly more believable. Old computers often have strange features which are omitted from their successors due to being rarely used (for instance, the original IBM PC could use current loop on its serial port connector). One could imagine someone with access to a time machine taking a short trip to the past just to grab one of these old computers as a replacement for a failed one.