Drawing inspiration from Sol LeWitt’s privileging of drawing concept over the material space of actual drawing, computational art typically focuses on the conceptual logic of the software program rather than the electronic space of program execution. The latter is positioned as secondary – a mere technical means. I wish to suggest a more equal and complex relationship. This is not, however, to lend the computer some awkward creative agency (or even to envisage a dimension of generative semi-autonomy); it is to consider the labour of the computer – to think through the implications of its iterative event-space. Programming itself demands thinking in terms of this labour. Creative concepts do not simply precede computation but are developed in relation to a language of data-structures and algorithms which has its basis in the possibility of non-reflective mechanical operation. Of course, the actual texture of computer labour is largely invisible – happening so quickly and at such an alien scale that there is no adequate human way of observing the process. This does less, however, to obliterate the importance of computer operation within computational art than to highlight its poignancy and power. The terrain of execution takes shape as the spatially and temporally obscure space in which the conceptual logic of the program gains concrete realisation. The two are tied together, neither subordinate to the other. If anything, in its silence and disappearance the plane of execution provides the well of darkness from which the potential for creative conceptualisation emerges.