10 print chr$(14) : rem switch to upper+lower case set
20 print "read seq file input.txt and write to seq file output.txt"
30 open 4,8,4,"input.txt,seq,read"
40 open 8,8,8,"@:output.txt,seq,write" : rem '@'== new file
50 for i=0 to 1 : rem while i==0
60 input#4,a$
70 i=64 and st : rem check bit 6=='end of file'
80 print a$
90 print#8,a$
100 next : rem end while
110 close 4
120 close 8
130 end