The Morley adapter utilises the next generation of teletext reception chips, which integrates all of the decoding and page acquisition into hardware. It uses the SAA5243 decoder which supports simultaneous grabbing of four pages, which the micro then reads out of its RAM.
This means that the Beeb has a lot less work to do, and the hardware is much simpler. The downside is that there is no longer low-level access to the raw datastream, so software is limited to the capabilities of the SAA5243 chip (basically teletext page grabbing only).
This means that the Beeb has a lot less work to do, and the hardware is much simpler. The downside is that there is no longer low-level access to the raw datastream, so software is limited to the capabilities of the SAA5243 chip (basically teletext page grabbing only).
Statistics: Posted by guesser — Tue May 06, 2025 1:32 pm