First, computer's(programmable subjects) are not necessarily non-organic(i.e purely electronic or mechanical). For instance, leech neurons can currently be used to create a computer that can find it's own ways to find solutions to problems.
http://news.bbc.co.uk/1/hi/sci/tech/358822.stmThat said, Belthasar has been noted for programming poyozo dolls and his personal Nu, with which he still referred to it as a "creature". Perhaps meaning that Belthasar's Nu was a biological computer... Add to that, the notion that Enhasa was beginning to scientifically analyze magic and synthesize magical artifacts such as the 'tabs', magical equipment(as V pointed out earlier), produce Masa, Mune and Doreen and create the Mammon Machine. As well as Belthasar eventually created the Wings of Time, which leads to the conclusion that holography and magical imbuing are not beyond his reach, but rather well within his grasp.
Perhaps Spekkio was intended to be Belthasar's Magnum Opus, combining his programming expertise, the technology from magic research and the concepts of how the dream creatures function(able to behave like sentient entities or as usable conduits of energy).