Instead of showing the upper control codes like this:

   ^À ^Á ^Â ^Ã ^Ä ^Å ^Æ ^Ç ^È ^É ^Ê ^Ë ^Ì ^Í ^Î ^Ï
   ^Ð ^Ñ ^Ò ^Ó ^Ô ^Õ ^Ö ^× ^Ø ^Ù ^Ú ^Û ^Ü ^Ý ^Þ ^ß

show them like this:

   ^` ^a ^b ^c ^d ^e ^f ^g ^h ^i ^j ^k ^l ^m ^n ^o
   ^p ^q ^r ^s ^t ^u ^v ^w ^x ^y ^z ^{ ^| ^} ^~ ^=

The lower control codes continue to be shown like this:

   ^@ ^A ^B ^C ^D ^E ^F ^G ^H ^I ^J ^K ^L ^M ^N ^O
   ^P ^Q ^R ^S ^T ^U ^V ^W ^X ^Y ^Z ^[ ^\ ^] ^^ ^_

The representation of DEL (0x7F) continues as ^?.

Further, use knowledge of UTF-8 to avoid a roundtrip through
wide characters.