teletext decoder part s

11-38 — elektor november 1981 teletext teletext decoder . . . that does not require modifications to the TV set After the detailed introduction to Teletext given last month, this article deals with the practical side of the project. To keep the whole thing within manageable limits, the circuit description wilt be as brief as possible. This leaves room to pay closer attention to three important aserts: modifying a TV set if the decoder is to be built in; calibration article dia Teletext de- coder and the circuitt--diiaaggrraam for it is shown in figure 1. This is a repeat of_ figure 13 in part 1, so many readers may already be familiar with it. The function of the various LSI chips have already been discussed in part one, therefore the operation of this part of circuit should be fairly clear, at least in the main outlines. The ICs 5 through 9 form the external address counter and page memory (see SAA 5020 of part 1). The remaining part is the control which is clearly separated fr...