maxwell@orphan.DEC (04/19/85)
[Sorry, about the incomplete version. ^C is too easy to type, sometimes....] For the last couple of years, I've been drooling over what little information I've been able to accumulate about Zilog's Z80 descendant, the Z800. The thought of a Z80 with real addressing modes, 16-bit operations including multiply and divide, system and user modes, and built in memory management, really makes this old Z80 programmer believe in a Santa Claus. All this and Z80 object compatability, too. Wow! So, with a large archive of Z80 code, and several Z80 based machines gathering dust in my home, I have decided to build a Z800 machine to replace them. This will allow me to continue using much of my older Z80 code, but eventually allow for a more robust operating system and tools, once I complete modification of a C compiler to take advantange of the Z800 enhancements. The problem is, Santa Claus is late, and isn't talking. Zilog has been promising the Z800 (and Z80000) for some time now. Last year, "The Z800 and Z80000 will be available in February, 1985". This year, "The Z800 won't be available until 1986". Additionally, pitifully little useful documentation is available. For example, though I know what the new instructions and addressing modes are by name, it's rather hard to write a Z800 assembler if the opcode/operand formats and values aren't published. It's also hard to begin designing hardware when chip timing diagrams are just pretty pictures without specific timing data. Does anyone out there know what's going on? Does anyone have opcode/operand listings? Does anyone have timing diagrams with numbers on them? Is Zilog really going to ship this processor, or will it always be coming out "next year"? Please respond to me directly. Useful information will be summarized and published in this august journal, if there is interest, and if there is anything concrete to report. -+- Sid Maxwell [The standard disclaimer should go here, but I'm not sure that any of my opinions are interesting or important enough for *anyone* to worry about....]