IIRC, AI 23b added functions for the Red Top missile (beam and head-on firing) and there were some enhanced ECM facilities. These were in ‘computer red’; those features which were not applicable to Saudi Aircraft resulted in different ‘colour’ computers.
I am not sure if the Saudis bought the air-to-air unguided rocket-pack option (AI 23b function ? ), although they may have used them air-to-ground (not an AI function ? ); there may have been other changes due to the bombs fit etc.
For the era, AI 23 was a remarkably capable system with some very advanced features. The radar and the missiles had good capability in the then ECM environment, and overall, they had a very good ‘kill’ probability, better than comparable systems at the time and initially better than the UK Phantom fit, although the latter had a better radar (and a Nav).