This research focuses on some of the affordances provided by SimCalc software, suggesting that its use can have important consequences for students' mathematical affect and motivation. We describe an episode in an inner-city SimCalc environment illustrating our approach to the study of affect in the mathematics classroom. We infer students' development of new, effective affective pathways and structures as they participate in conceptually challenging mathematical activities. Our work highlights the roles of dignity and respect in creating an emotionally safe environment for mathematical engagement, and makes explicit some of the complexity of studying affect.