yann64andClaude Opus 5.5
cf3a03350c
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01YDRjtmAiNpo5mK5N3d7QwZ
21 lines
3.8 KiB
HTML
21 lines
3.8 KiB
HTML
{
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"title": "ZILOG Z8000",
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"date": "1979-04-01",
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"years": [
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"1979"
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],
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"topics": [
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"Hardware"
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],
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"params": {
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"when": "APRIL 1979",
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"oc_id": 52,
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"source": {
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"url": "https://web.archive.org/web/20221215134357/http://www.old-computers.com/history/detail.asp?n=52",
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"date": "2022-12-15"
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}
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}
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}
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<img src="/media/history/images/timeline_0479_z8000_2.jpg"/> <br/><br/><p> The Z8000 CPU series was introduced in early 1979, between the launch of the Intel <b>8086</b> (April 1978) and the Motorola <b>68000</b> (September 1979). <br/><br/> Two versions were released, the <b>Z8001</b> capable of addressing 8 MB of memory via segment registers, and the <b>Z8002</b> which could only address 64 KB. Like the Zilog Z80, the Z8000 included built-in DRAM refresh circuitry. An optional <b>Z8010</b> MMU (Memory Management Unit) co-processor allowed up 48 MB of memory to be addressed. <br/><br/> Internally the Z8000 chip held 17500 transistors in NMOS design, and it had sixteen 16 bit registers which could be extremely flexibly used. The programmer could see them as 16 8-bit, 16 16-bit, 8 32-Bit, or 4 64-bit registers. All registers were general-purpose registers, although registers 14 and 15 were usually used as stack segment and pointer. Among its 110 instructions and 13 addressing modes, the Z8000 also offered 32-bit multiplication and division instructions. <br/><br/> There was both a user mode, for programs, and a supervisor mode, for the operating system. The user mode prevented access to potentially dangerous things such as interrupt handling. <br/><br/> Despite these attractive features the Z8000 was not very fast and suffered from some internal bugs. It was thus never very popular and was surpassed a few months later by the Motorola 68000 and later, by the Intel 286. <br/><br/> The Z8000 can be found in some rare but well-known computers though, such as the Olivetti M20 and M40, and the Unix-based Commodore 900. Some third parties also manufactured the Z8000 including AMD, Hitachi and Sharp. <br/><br/> The Z8000 was followed in 1986 by the <b>Z80000</b>, an amazing 32 bit processor whose features (pipeline, cache memory) would not appear until six years later in Intel processors. <br/> The Z8000 is still alive nowadays with the Z16C00, a CMOS version mainly used in embedded applications. <br/></p>_______________________<br/><p> <b>Mike Throm's</b> memories:<br/> I worked in Zilog's system division for 6 years. The primary goal was to design systems using Zilog processors. One of the notable leaders of Zilog's system engineering group was <b>Judy Estrin</b> who lead the effort to develop an ethernet like LAN product for Zilog, who then went on to other ventures like Bridge Communications (acquired by 3Com), NCD, and Precept.<br/> Zilog also designed a UNIX "supermicro" system called the S8000 initally based on the Z8000, then the Z80000 with a UNIX based OS called Zeus.<br/> Like most silicon valley firms of the time, we took pride in what we did and spent long hours to develop products. 60 - 80 hours per week during peak development cycles were common. Also, because almost all of us were under 30, weekend parties and "beer busts" were also common between development cycles.<br/> Many S8000 units were sold to the IRS; however, the system side of the business never took off and was eventually closed down around 1985. <br/><br/> <b>Peter Sandilands</b> adds:<br/> The Z8000 was used in a quite successful line of computers from Onyx Inc (California). Originally built for AT&T they ran Unix V7 and Interactive Systems IS/1.<br/> The architecture continued into the mid '80s and ran Sys III. Sold as general purpose business computers they had the option of a number of bundled business packages using software such as Quadratron word processor. New Onyx C8002s were still being sold in 1986!<br/><br/></p><img src="/media/history/images/timeline_0479_z8000_1.jpg"/>
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