64 bit Oberon

To exploit the 64 bit address space, we migrated ModulaWare's 32 bit Oberon System [DG 96] to OpenVMS Alpha V7.1 [AXP] using very large memory [VLM]. We describe the required language extensions of the Oberon-2 programming language in order to support 64 bit pointers and 64 bit integers. The goal was to keep the number of languages extensions minimal and to disallow any language changes which would break existing code developed for the 32 bit Oberon System. We also summarize the modifications required to get the Oberon System running in the 64 bit address space.