There are many perceived benefits of using technology, such as computer algebra systems, in undergraduate mathematics courses. However, attaining these benefits sometimes proves elusive. Some of the key variables are the teaching approach and the student instrumentation of the technology. This paper considers the instrumentation of computer-based algebra systems (CAS) by first- and second-year university students. The responses to a survey of the classes showed that instrumentation was more advanced for the second year students. The progress of each group is described and a number of student categories are outlined, in terms of their attitude to the computer and their instrumentation level.