This is equivalent to choice 1. How can this LCD show the extended characters?
It shows blank spaces instead.
Another problem is the code page switching using the control characters. If you try the example from the RDS standard:
For example, the name of the second Greek program service could be transmitted in type 0 groups as follows:
Characters: ΔE YT EP O (Text segment address: 0 1 2 3)
Text segment address - Character codes - Characters Effect
0 - 0/14, 0/14 - SO, SO Selection of code-table E.2 (control characters)
0 - 15/14, 4/5 - Δ, E First two letters
1 - 5/9, 5/4 - Y, T Second two letters
2 - 4/5, 5/0 - E, P Third two letters
3 - 4/15, 2/0 - O, Last letter and spacethis will result in blinking the first PS segment on many receivers because they interpret the control characters as any other characters. So they show in sequence two blank spaces and then space and E as the first PS segment.
There's a big mistake in the RDS standard. It should be strictly claimed that receivers with simple LCD or no code page switching implemented must ignore all characters in ASCII range 0 to 31. It's a pity that there is only one PS and one RT possible at one time. Better option would be to transmit primary PS and RT that can be showed on any LCD and secondary PS and RT with extended characters that can be showed on clever receivers. Unfortunately this is only an imagination, today it's probably too late to think about it. As a result, the extended character sets are generally useless for PS and RT (but are not excluded for use with some special services, of course).