See background information here.
In the Harmonious Republic of Mars, the finest forms may be found of any and all luxuries available in the Solar system. This includes moving pictures. Only in the Harmonious Republic does mankind watch, rather than read, the news. And in color!
With blasphemous computers banned for all time, these television devices were thought to be relegated to the history books. But through decades of dedicated work in the Bureau of Public Entertainment, a new style of moving picture screen was developed, so that in all public spaces a person might be able to follow the pronouncements of the Supreme Council of Harmony or any other part of the Harmonious Bureaucracy.
For those honored to be members of the Harmonious Cohort, a moving picture screen in the home is even possible. Indeed, life is good here on the Red Planet.
The GE Porta-Color is the last all CRT color television made in the US. Given that computers are banned, and given all current and plausible near-future technology, what advances could be made over the Porta-Color? How high of a definition could TV screens in public places (not necessarily affordable for a private home) have?
Computers are banned. Thinking about a computer will get you burned at the stake. Therefore, people don't think about making computers.
For the purposes of the question, anything that has electronic memory is a computer. Anything that has software that can be programmed is a computer. Anything that was ever historically considered to be an electronic computer is a computer.
An electric calculator has electronic memory and is a computer. Slide rules and nomographs are examples of mechanical 'computers' that have no memory other than their current state; they are not computers.
The GE Porta-Color is not programmable and has no memory, therefore it is not a computer. Any ASIC that can be cost effectively designed entirely by hand (and doesn't have any memory, and is not programmable) is not a computer.
Transistors, and thus LEDs, are not banned. Whether you could develop LEDs without betting burned at the stake is another matter.
All materials available at the present day will be available in the Harmonious Republic, unless those materials cannot be created without a computer.
Plausible near-future technology means something where most of the engineering problems have been solved and the only remaining obstacles are refinement or cost or culture.
For example, universal smart glasses are plausible near-future technology, fusion power is not. Self-driving cars would be plausible too, except those would definitely get you burned at the stake.