Editing DEC PRISM (section)

===Cancellation===
Throughout the PRISM period, DEC was involved in a major debate over the future direction of the company. As newer RISC-based workstations were introduced, the performance benefit of the VAX was constantly eroded, and the [[price/performance ratio]] completely undermined. Different groups within the company debated how to best respond. Some advocated moving the VAX into the high-end, abandoning the low-end to the workstation vendors like Sun. This led to the [[VAX 9000]] program, which was referred to internally as the "IBM killer". Others suggested moving into the workstation market using PRISM or a commodity processor. Still others suggested re-implementing the VAX on a RISC processor.{{sfn|Supnik|2008}}

Frustrated with the growing number of losses to cheaper faster competitive machines, independently, a small [[skunkworks project|skunkworks]] group in [[Palo Alto]], outside of Central Engineering, focused on workstations and UNIX/[[Ultrix]], entertained the idea of using an off-the-shelf RISC processor to build a new family of workstations.  The group carried out due diligence, eventually choosing the [[R2000 (microprocessor)|MIPS R2000]]. This group acquired a development machine and prototyped a port of Ultrix to the system. From the initial meetings with MIPS to a prototype machine took only 90 days. Full production of a DEC version could begin as early as  January 1989, whereas it would be at least another year before a PRISM based machine would be ready.{{sfn|Supnik|2008}}

When the matter was raised at DEC headquarters the company was split on which approach was better. Bob Supnik was asked to consider the issue for an upcoming project review. He concluded that while the PRISM system appeared to be faster, the MIPS approach would be less expensive and much earlier to market. At the acrimonious review meeting by the company's Executive Committee in July 1988, the company decided to cancel Prism, and continue with the MIPS workstations and high-end VAX products. The workstation emerged as the [[DECstation 3100]].{{sfn|Supnik|2008}}

By this time samples of the microPRISM had been returned and were found to be mostly working. They also proved capable of running at speeds of 50 to 80&nbsp;MHz, compared to the R2000's 16 to 20. Performance predictions based on these observations suggested a significant performance improvement over existing and announced RISC products from other vendors. However, without the accompanying floating-point unit, whose design had been halted, or the cache interface chip required for operating at such frequencies, which had been part of a cancelled project, floating-point performance predictions remained hypothetical.<ref name="digital19881021_uprism">{{ cite tech report | url=http://bitsavers.org/pdf/dec/prism/memos/881021_uPRISM_charcterization.pdf | title=uPRISM - The Final Chapter | publisher=Digital Equipment Corporation | date=21 October 1988 | access-date=17 February 2024 }}</ref>