Here's a puzzle in the from of a program. Regards to all! Tom program inout (input,output); (* version = 1.01 of inout.p 2010 Aug 12 2010 Aug 12, 1.01: testing on Sun 2010 Aug 12, 1.00: origin on mac Thomas D. Schneider, Ph.D. National Institutes of Health Gene Regulation and Chromosome Biology Laboratory schneidt@mail.nih.gov http://alum.mit.edu/www/toms (permanent) Test input string in GPC. The program reads one character from the user at a time. If the user types the wrong character and wishes to correct it, then they should be able to type control-H (^H) or delete and correct the input. This works with GPC on a Sun computer, but on a Mac OSX (10.6.2) one instead sees '^H' and no backspace occurs. What can be done at compile time to make backspace work on the Mac? ******************************************************************************** On a Sun computer: % inout h the character was h u the character was u b the character was b z the character was z a the character was a b the character was b q the character was q Backspace (control-H) and delete work as expected. On a Mac: % inout a the character was a abcd the character was a abcd^H^H^H^H^H^H^H^H control H or delete gives same^H^H^H the character was a q the character was q Backspace (control-H) and delete do not work. *) var n: char; (* a character from the user *) begin n := ' '; while (n <> 'q') do begin readln(input, n); writeln(output, 'the character was ',n); end; end.