Published online by Cambridge University Press: 27 November 2015
Let   $\unicode[STIX]{x1D6FD}_{1},\unicode[STIX]{x1D6FD}_{2}>1$  and
 $\unicode[STIX]{x1D6FD}_{1},\unicode[STIX]{x1D6FD}_{2}>1$  and   $T_{i}(x,y)=((x+i)/\unicode[STIX]{x1D6FD}_{1},(y+i)/\unicode[STIX]{x1D6FD}_{2}),i\in \{\pm 1\}$ . Let
 $T_{i}(x,y)=((x+i)/\unicode[STIX]{x1D6FD}_{1},(y+i)/\unicode[STIX]{x1D6FD}_{2}),i\in \{\pm 1\}$ . Let   $A:=A_{\unicode[STIX]{x1D6FD}_{1},\unicode[STIX]{x1D6FD}_{2}}$  be the unique compact set satisfying
 $A:=A_{\unicode[STIX]{x1D6FD}_{1},\unicode[STIX]{x1D6FD}_{2}}$  be the unique compact set satisfying   $A=T_{1}(A)\cup T_{-1}(A)$ . In this paper, we give a detailed analysis of
 $A=T_{1}(A)\cup T_{-1}(A)$ . In this paper, we give a detailed analysis of   $A$  and the parameters
 $A$  and the parameters   $(\unicode[STIX]{x1D6FD}_{1},\unicode[STIX]{x1D6FD}_{2})$  where
 $(\unicode[STIX]{x1D6FD}_{1},\unicode[STIX]{x1D6FD}_{2})$  where   $A$  satisfies various topological properties. In particular, we show that if
 $A$  satisfies various topological properties. In particular, we show that if   $\unicode[STIX]{x1D6FD}_{1}<\unicode[STIX]{x1D6FD}_{2}<1.202$ , then
 $\unicode[STIX]{x1D6FD}_{1}<\unicode[STIX]{x1D6FD}_{2}<1.202$ , then   $A$  has a non-empty interior, thus significantly improving the bound from Dajani et al [Self-affine sets with positive Lebesgue measure. Indag. Math. (N.S.)25 (2014), 774–784]. In the opposite direction, we prove that the connectedness locus for this family studied in Solomyak [Connectedness locus for pairs of affine maps and zeros of power series. Preprint, 2014, arXiv:1407.2563] is not simply connected. We prove that the set of points of
 $A$  has a non-empty interior, thus significantly improving the bound from Dajani et al [Self-affine sets with positive Lebesgue measure. Indag. Math. (N.S.)25 (2014), 774–784]. In the opposite direction, we prove that the connectedness locus for this family studied in Solomyak [Connectedness locus for pairs of affine maps and zeros of power series. Preprint, 2014, arXiv:1407.2563] is not simply connected. We prove that the set of points of   $A$  which have a unique address has positive Hausdorff dimension for all
 $A$  which have a unique address has positive Hausdorff dimension for all   $(\unicode[STIX]{x1D6FD}_{1},\unicode[STIX]{x1D6FD}_{2})$ . Finally, we investigate simultaneous
 $(\unicode[STIX]{x1D6FD}_{1},\unicode[STIX]{x1D6FD}_{2})$ . Finally, we investigate simultaneous   $(\unicode[STIX]{x1D6FD}_{1},\unicode[STIX]{x1D6FD}_{2})$ -expansions of reals, which were the initial motivation for studying this family in Güntürk [Simultaneous and hybrid beta-encodings. Information Sciences and Systems, 2008. CISS 2008. 42nd Annual Conference 2008, pp. 743–748].
 $(\unicode[STIX]{x1D6FD}_{1},\unicode[STIX]{x1D6FD}_{2})$ -expansions of reals, which were the initial motivation for studying this family in Güntürk [Simultaneous and hybrid beta-encodings. Information Sciences and Systems, 2008. CISS 2008. 42nd Annual Conference 2008, pp. 743–748].