I recently had a discussion about analog computing with someone who works actively on hybrid analog-digital systems at the integrated circuit level. My proposal was that there seems to be, based on historical accounts and reflection, two differing views on “analog”: 1) analog reflecting the continuous or discrete character of magnitude of a variable, and 2) isomorphism indicated by construing analog to be associated closely with analogy. To take one example which can serve for discussion: Are Minecraft circuits analog, digital, or both? It depends on how we define “analog” and where we focus (on the issue of representation or magnitude). For example, redstone circuits could be viewed as analog computing in the sense that the circuits are analogous to electronic circuits containing gates such as and, or, xor, etc. And yet, at the bottom of the vast hierarchy of translation, we have Minecraft servers and clients working on top of a digital substrate. In the mid 90s, I bought a Nord Lead for my synthesizer collection, and Nord uses “virtual analog” to characterize their lineup (an analog front end and a digital back end): http://www.nordkeyboards.com/products/nord-lead-2x My view is that the issue of magnitude is a side-effect of “analog as analogy and, thus, isomorphism", and thus not primary. Tangible objects when juxtaposed and configured together to form physical analogies happen to be continuous simply because reality and our physiology is continuous, and we employ real objects (at least in the mind) when forming analogies. This view may need tweaking, but it seems as though the knowledge of such things is present in this forum. What are the thoughts on this? Is this an ongoing point of debate among historians? -paul Paul Fishwick, PhD Chair, ACM SIGSIM Distinguished University Chair of Arts & Technology and Professor of Computer Science Director, Creative Automata Laboratory The University of Texas at Dallas Arts & Technology 800 West Campbell Road, AT10 Richardson, TX 75080-3021 Home: utdallas.edu/atec/fishwick Blog: creative-automata.com