Whole replacement of 3.8L PCM

I'm wondering, does such an animal exist? Back in the 90s, when cars were already somewhat computerized with DIS, it was possible to buy replacement PCMs from e.g. JET. The old JK was even more popular throughout its lifetime than some of the models for which JET built computers. Nonetheless, it appears that any chipping solutions we have now are limited to tinkering with idle speed through external means. Or at least I cannot find anything else with Web search. Anyone heard anything?