John von Neumann also consulted for the ENIAC project. The electronics of the new ENIAC ran at one-sixth the speed, but this in no way degraded the ENIAC's performance, since it was still entirely I/O bound. Complicated programs could be developed and debugged in days rather than the weeks required for plugboarding the old ENIAC. Some of von Neumann's early computer programs have been preserved. The next computer that von Neumann designed was the IAS machine at the Institute for Advanced Study in Princeton, New Jersey. He arranged its financing, and the components were designed and built at the RCA Research Laboratory nearby. John von Neumann recommended that the IBM 701, nicknamed the defense computer include a magnetic drum. It was a faster version of the IAS machine and formed the basis for the commercially successful IBM 704.
Try to answer this question if possible (otherwise reply "unanswerable"): After the design of IAS, who built the computer?
RCA Research Laboratory