that's for ground based testing equipment.
the shuttle itself uses multiple redundant radiation hardened AP-101 systems made by IBM.
Even the latest greatest computer systems used in space are a customized version of the processor found in the original imac, as radiation hardening is non-trivial.
usually the customization is simply just extra ceramic radiation protecting packaging around the chips, and fabricated the chips at a much lower and more stabale process. And the redundacy isusually just standard triple-modular redundacy with voting.
