This ties in with something called 'fair use' under US IP law, see here: https://en.wikipedia.org/wiki/Fair_use for more. Basically, 'fair use' permits _limited_ use of copyrighted material without acquiring permission from the IP owners; there is a 4-part test which is applied to determine whether a non-licensed use meets 'fair use'. The parts are: "- the purpose and character of the use, including whether such use is of a commercial nature or is for nonprofit educational purposes; - the nature of the copyrighted work; - the amount and substantiality of the portion used in relation to the copyrighted work as a whole; and - the effect of the use upon the potential market for or value of the copyrighted work." ii) doesn't really apply here, and of course one would score poorly on iii), but since a) one's not making any money from it, that would score highly under i), and b) there is zero effect on the market, since the thing isn't even for sale, so scoring highly under iv). So use for vintage computer hobby puposes might well be (in the US at least) 'fair use', and not in fact infringing, even without a license. In other countries, it will depend on their copyright laws; e.g. in Israel and Poland, the same might be true. Noel