Asymptotically Optimal Low-Cost Solid Codes H. J\"urgensen, S. Konstantinidis, N. H. L\^am A new construction of solid codes is introduced. With this construction one obtains classes of solid codes which are asymptotically optimal in terms of information rate and which have low-cost systematic encoding and decoding agorithms. The construction uses a new result on the asymptotic average length of maximal runs in words.