Zilog Z80
Summary
The Zilog Z80 is closely associated with the Italian physicist Federico Faggin. Faggin initially works in the Italian branch of Fairchild, later moving to Intel, where he developed the 4004 and 8008. With his close colleague Ralph Ungermann, Faggin founded Zilog in October 1974. The target is a binary-compatible processor to the Intel 8080. The Z80 CPU is created and the first processors are launched in 1976. The CP/M operating system and Intel’s PL/M compiler run unmodified on the Z80 CPU.
The team is small at first — just eleven people are planning the Z80. And Zilog doesn’t produce itself, that’s what Synertek and Mostek do. Home computers like ZX80, ZX81 from Sinclair or TRS-80 from Radio Shack are based on the CPU, as are game consoles like the Sega Mega Drive, which brings a lot of money and own production units are added at the end of 1976. The 6502 and Z80 are the most common processors between the late 1970s and mid 1980s.
Long description
The Zilog Z80 is closely associated with the Italian physicist Federico Faggin. Faggin initially works in the Italian branch of Fairchild, later moving to Intel, where he heads the 4004 project. At the 8008 he is a leading engineer in processor development and drives the Intel CPU almost independently. Intel doesn’t thank him and a frustrated Faggin resigned in August 1974, also because there are disputes over an earlier patent, and he has to sign up on a list of latecomers — a delay is not avoidable in an 80-hour week.
With his close colleague Ralph Ungermann, Faggin founded Zilog in October 1974. The target is a binary-compatible processor to the Intel 8080. The Z80 CPU is created and the first processors are launched in 1976. The CP/M operating system and Intel’s PL/M compiler run unmodified on the Z80 CPU. However, with a copy of the machine commands it does not remain, more commands are added. However, Zilog needs to introduce a new assembler syntax because Intel has a copyright on assembler mnemonics; MOV B,C becomes LD B,C.
The team is small at first — just eleven people are planning the Z80. And Zilog doesn’t produce itself, that’s what Synertek and Mostek do. Home computers like ZX80, ZX81 from Sinclair or TRS-80 from Radio Shack are based on the CPU, as are game consoles like the Sega Mega Drive, which brings a lot of money and own production units are added at the end of 1976. The 6502 and Z80 are the most common processors between the late 1970s and mid 1980s.
Formerly Zilog’s sponsor is Exxon, which holds 51% of the company’s shares. That turned out to be a problem. Zilog is much more successful with the Z80 than Intel with the 8080. Nevertheless, IBM chooses the Intel 8088 to build its PC because Exxon is in the “War with IBM”. After the 8-bit computers declined, Zilog cannot come up with reliable 32-bit processors, and Z8000 and Z80000 are not successful. IXYS Corporation buys Zilog for 62 million US dollars, descendants of the Z80 processors are still produced today.
Sources and further links
Connections in the collection
In the exhibition concept
- 2 CPUs for the mass market · Area B, Section 2