Beginning in 1985, Apple Computer, Inc., and several school districts began a collaboration to examine the impact of computer saturation on instruction and learning in K-12 classrooms. The initial guiding question was simply put: What happens when teachers and students have constant access to technology? To provide "constant access," each teacher and student in the project received two computers, one for the home and one for the classroom. This paper describes the program, Apple Classrooms of Tomorrow (ACOT), and reports on the instructional evolution that occurred in those classrooms. The personal struggles of teachers who came to confront the nature of learning and consequently, the efficacy of their own instructional practices, are examined in detail through individual journal entries. This paper also places the innovative ACOT program in a broader perspective on educational change and draws implications for the support and development of teachers engaged in significant reform projects. (67 references) (DB)