Guess the language

[sassa_nf]

2.2.0 :001 > abc = 129.times.map { |i| i }.pack('C*').force_encoding('iso-8859-1')
 => "\x00\x01\x02\x03\x04\x05\x06\a\b\t\n\v\f\r\x0E\x0F\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1A\e\x1C\x1D\x1E\x1F !\"\#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~\x7F\x80" 
2.2.0 :002 > duh = abc.reverse.force_encoding('ASCII-8BIT')
 => "\x80\x7F~}|{zyxwvutsrqponmlkjihgfedcba`_^]\\[ZYXWVUTSRQPONMLKJIHGFEDCBA@?>=<;:9876543210/.-,+*)('&%$#\"! \x1F\x1E\x1D\x1C\e\x1A\x19\x18\x17\x16\x15\x14\x13\x12\x11\x10\x0F\x0E\r\f\v\n\t\b\a\x06\x05\x04\x03\x02\x01\x00" 
2.2.0 :003 > abc[0..-1] = duh
 => "\x80\x7F~}|{zyxwvutsrqponmlkjihgfedcba`_^]\\[ZYXWVUTSRQPONMLKJIHGFEDCBA@?>=<;:9876543210/.-,+*)('&%$#\"! \x1F\x1E\x1D\x1C\e\x1A\x19\x18\x17\x16\x15\x14\x13\x12\x11\x10\x0F\x0E\r\f\v\n\t\b\a\x06\x05\x04\x03\x02\x01\x00" 

All is well? Repeat:

2.2.0 :004 > abc = 129.times.map { |i| i }.pack('C*').force_encoding('iso-8859-1')
 => "\x00\x01\x02\x03\x04\x05\x06\a\b\t\n\v\f\r\x0E\x0F\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1A\e\x1C\x1D\x1E\x1F !\"\#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~\x7F\x80" 
2.2.0 :005 > abc[0..-1] = duh
Encoding::CompatibilityError: incompatible character encodings: ISO-8859-1 and ASCII-8BIT