46. Extra-large printing
    ~~~~~~~~~~~~~~~~~~~~
This is a demonstration program which creates attractive enlarged characters
very simply. It makes use of a look-up table in the 1.20 Operating System
ROM, which the machine normally uses in Modes 0 to 6. This particular example
uses the table to create attractive block characters in teletext Mode 7. You
could modify this for inclusion into your own programs, to create special
headings. This is based on ideas from "Acorn User" and "Micro Programmer".

 10 MODE7:E%=144:REPEAT:PRINT"Press a Key...":A%=&C000+8*(GET-32)
 20 E%=145+(E%-144)MOD7:FORB%=A%TOA%+7:C%=?B%
 30 PRINTCHR$(E%)CHR$(154);:FORD%=7TO0STEP-1
 40 IF(2^D%ANDC%)THENPRINTCHR$(255);ELSEPRINT" ";
 50 NEXT:PRINT:NEXT:UNTILFALSE