1. Synthese recently published Pierre Wagner's article Carnapian and Tarskian Semantics, which outlines some important differences between semantics as Tarski conceived it (at least in the 1930s-40s) and as Carnap conceived it. This is important for anyone who cares about the development of semantics in logic; I'd been hoping someone would write this paper, because (a) I thought it should be written, but (b) I didn't really want to do it myself. Wagner's piece is really valuable, in my opinion. And not merely for antiquarian reasons: many today have the feeling that semantics in logic (roughly: model theory) is the natural/ inevitable way to come at semantics in logic. But how exactly to pursue semantics was actually very much up for debate and in flux for about 20 years after Tarski's 1933 "On the Concept of Truth in Formalized Languages." And the semantics in that monograph is NOT what you would find in a logic textbook today.
2. I am currently putting the finishing touches on volume 7 of the Collected Works of Rudolf Carnap, which is composed of Carnap's three books on semantics (Introduction to Semantics, Formalization of Logic, and Meaning and Necessity). There is a remark in Intro to Semantics that is relevant to Wagner's topic, which Wagner cited (p.104), but I think might be worth trying to investigate in more detail. Carnap writes:
our [= Tarski's and my] conceptions of semantics seem to diverge at certain points. First ... I emphasize the distinction between semantics and syntax, i.e. between semantical systems as interpreted language systems and purely formal, uninterpreted calculi, while for Tarski there seems to be no sharp demarcation. (1942, pp. vi-vii)
I have two thoughts about this quotation: