I only recently came across a mention of the Z8070 FPU for the Z8000 family. According to some benches, it was very fast given its HMOS implementation and clock.

Of the very little information I can find on it, one web page suggests it never made it into production. Does anyone know if this is true?

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    AFAIK the design was rather buggy, got never fully finished and stomped together with the Z80000. Although I once been told the Mil-version (Z16C70) was delivered.
    – Raffzahn
    Sep 30, 2022 at 22:16
  • @Raffzahn - C for CMOS? Oct 1, 2022 at 15:27
  • Just found some Z8000 info at kranenborg.org/z8000. As of 2003, the Z16C01 was in production as a CMOS Z8001, and the Z16C02 as a CMOS Z8002. Those had been in production since 1995 for "non-commercial embedded applications." The Z8070 FPU was apparently dropped early in the design phase. Oct 1, 2022 at 16:52
  • There's a preliminary device specification for the Z8070 in the 1985 Zilog Data Book at. bitsavers.org/components/zilog/_dataBooks That says it can do a single-precision multiply in 28 clocks at 10MHz, which isn't all that impressive. It looks intended to compete with the 8087, naturally enough. It has one significant improvement in that the floating-point registers are individually addressable, rather than forming a small stack, but apart from that, it looks rather complicated to use. Oct 1, 2022 at 17:07
  • @MauryMarkowitz yes, the 16Cxx series was CMOS. Mut more important was the MIL-Spec temperature range and durability.
    – Raffzahn
    Oct 1, 2022 at 17:09


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