Teletext displayed graphics characters
Codes in the range 0 to 31 are control codes which correspond to the VDU codes
described in Appendix 7.
Codes in the range 128 to 159 are the Teletext control codes which affect
subsequent characters in the same line (see page (C 61). The characters shown
in the table below are those displayed under the effect of a graphics control
code.
Each character has a code. Thus H is code 72 since it is in column 70, row 2.
App 2.5