Only if you don't spend hours looking for the transistors that flew off the end of your tweezers :-). My point is that while SOT23s didn't exist 40 years ago, there is no real reason to prohibit them in a project like this. Limit the number of transistors, sure. Insist on an architecture that could be built 40 years ago, sure. But should the use of a storage 'scope to debug the thing be prohibited too, on the grounds that hobbyists 40 yrars ago were lucky to have _any_ 'scope? Do you prohibit writing simulators for the transistorised machine, on the grounds that 40 years ago hobbyists wouldn't have had anything to run them on? -tony