What a milestone. Still my favorite processor, and I have about 10 here at home in various yet to be finished projects (of course).
The Zilog Z80 has turned 50
31–40 of 131 posts
Re: The Zilog Z80 has turned 50
#32The Z80 was how I learned assembly programming in high school.[0] Was a bit of an unusual choice, but high school students still carry these funky Z80 (or eZ80 now with the color screens) devices every day, so being able to hack on it and have plausible deniability while in class felt great :)
Re: The Zilog Z80 has turned 50
#33No mention of the TI-84 calculator? Used by millions of American schoolchildren, programmable in BASIC, and runs on Z80 (B/W models)/eZ80 (color display models) to this day
> Used by millions of American schoolchildren Europe too :) When I was in high school, TI-84 Plus was the calculator the school told all of us to buy. And I see that stores in my country are still stocking them so I have to assume they are still being bought and used. Many hours were spent by me and my friends making and showing off little programs in TI-BASIC on those calculators. None of us ever took it all the way…
It depends on the country I guess. In Spain I never saw a person using Texas Instruments calculators. Casio and HP are way more popular.
Re: The Zilog Z80 has turned 50
#34No mention of the TI-84 calculator? Used by millions of American schoolchildren, programmable in BASIC, and runs on Z80 (B/W models)/eZ80 (color display models) to this day
TI-83 for me. We didn't have that advanced technology.
TI-83 was built on Z80 as well. I remember hand-assembling a program for it with pen and paper, something I did earlier with the Sinclairs.
Re: The Zilog Z80 has turned 50
#35I started programming in 1978 (In Assembler) and wanted to know not only how the software worked but how the hardware worked. Found a great kit using the Z80 and built it and spent many nights with a logic probe and oscilloscope learning digital eletronics. Also devoured the Z80 manual learning the instruction set. I'm nearly 70 now but remember those days like they were yesterday. Truly a magnificent CPU
Same! Also built external peripherals for my ZX81.
Re: The Zilog Z80 has turned 50
#36Earlier quoted context omitted.
> Used by millions of American schoolchildren Europe too :) When I was in high school, TI-84 Plus was the calculator the school told all of us to buy. And I see that stores in my country are still stocking them so I have to assume they are still being bought and used. Many hours were spent by me and my friends making and showing off little programs in TI-BASIC on those calculators. None of us ever took it all the way…
It depends on the country I guess. In Spain I never saw a person using Texas Instruments calculators. Casio and HP are way more popular.
We had both depending on the school and sometimes even the teacher. fx-9750G and GII didn't support assembly programming... unless you used an undocumented procedure to flash them with unsupported firmware from a different calculator model...
Re: The Zilog Z80 has turned 50
#37Two of my favorite Z80 anecdotes. First, my Father wanted to try to add some peripherals to the original TRS-80 Model 1. So, what he was interested in doing was asserting the BUSREQ pin to tell the Z80 to get ready so that he could have the bus, ideally waiting for the BUSACK signal to know when it was his. Unfortunately, on the Model 1, when you assert the BUSREQ pin, it is tied directly to the tri-state buffers tha…
That just means you have a more exciting design problem! Now you have to stop the clock and then assert TEST for probably a certain maximum number of cycles (dynamic logic) before enabling the clock...
Re: The Zilog Z80 has turned 50
#38As the proud owner of a ZX-81 I remember staring at the Z80 instruction reference at the end of the user's manual without the faintest clue of what any of that meant. It took me some while before I managed to wrap my head around how CPUs actually run programs (vs. the high level abstractions like BASIC or other languages).
Actually, BASIC’s flat structure helped me a lot in understanding Z80 assembly when I was 12. You see, memory addresses were line numbers, registers were variables, JP was GOTO, CALL was GOSUB. CP was IF, JP, Z was THEN GOTO, and LD was LET, and so forth.
Re: The Zilog Z80 has turned 50
#39Happy birthday! The Z80 was the first CPU I rode, more luxurious than the subsequent 6502 and 6510. I still have a TI calculator with a low-energy Z80. Cheers to Rodnay Zaks for "Programming the Z80"!
https://archive.org/details/Programming_the_Z-80_2nd_Edition... is where I learned about the "W" and "Z" registers -- if you don't know what they do, I won't spoil your fun reading Zaks! See also http://www.z80.info/zip/z80-documented.pdf The MOS 6502 was introduced at the WESCON tradeshow in September 1975 and sold for $25 quantity 1. They had a transparent vase full of them, 'proving' they did volume -- but those w…
Spoiler: the undocumented WZ registers are just microcode temporaries to hold large operands. For instance when reading a jump instruction, the jump destination can't be read directly into PC since that would mess up reading the second half of it, so it's read into WZ and then WZ is transferred to PC. This is invisible to the programmer.
One might say the instruction is really "jump to WZ", or JWZ, which, of course, refers to Jamie Zawinski (not really).
Re: The Zilog Z80 has turned 50
#4035 years ago I had to program a Z80 by "assembling" programs by hand and punching hexcodes into a board. This was made easier by writing an assembler for it. This was my way into tools which took me eventually to working on a major C++ compiler.