I 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.
As 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).
That machine was my intro to computers too, and I was fascinated by “fast mode” blanking the screen and the interesting tradeoffs between hardware and software.
This is the CPU that I first learned to code on, first in TI Basic (TI-8[1356] ftw) and then Z80 assembler. Crazy to think that the CPU was "old" when I started, and it's still doing good work in those calculators even 20+ years later.
No 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
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 to learning Z80 assembly however. I printed a whole manual about Z80 assembly programming for the TI-84 Plus and started reading it but never wrote a single line of assembly for it. Yet.
Same here (actually had a voyage 200, but same same I guess). It's actually quite insulting that TI kept (and keeps?) selling waaay outdated hardware at horrendous prices. It's the SAP/Oracle business model applied to school hardware.
There are plenty of open core alternatives that replicate the architecture and ISA. Many of these are cycle accurate. Some have been tape-out proven. Hobbyist retro-computing enthusiasts who wish to build a Z80 system still have options even once new old stock and recovered CPUs become scarce.
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 that handle the address and data bus. So, as soon as you make the request, the Z80 loses all access to its memory and data -- mid cycle. Which, you know, can be Bad. Radio Shack labels this pin TEST and uses it for internal testing. But it was definitely a bit of a disappointment to my Fathers efforts.
The second one is when I learned that the Game Boy Advance has a Z80 built into its chip. The designers drag and dropped a Z80 core (tweaked for GB) just so they could run legacy GB games on it. It just kind of bends your view of the computing world when something as significant as a Z80 can just be shoved into the corner of a die for "just in case" functionality.
I still remember clearly sitting down to play with the TRS-80 at the local Radio Shack in the 1970s
Unlike anything I had ever experienced, it was life changing, I would bike to the store every day after school
Family couldn't afford the computer but I bought all the books and would read them at home over and over and gawk at all the accessories in the catalogs
Then family surprised me with it as a birthday present with all the relatives paying for it, pretty sure I was the only person in town with one, even the school didn't get one for years
Didn't have any way to save programs, not even the cassette recorder which was too expensive, had to memorize them and retype every time I turned it on
Happy 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.
I 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
As 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).
That machine was my intro to computers too, and I was fascinated by “fast mode” blanking the screen and the interesting tradeoffs between hardware and software.
There is a drop in compatible FOSS clone of Z80 https://github.com/rejunity/z80-open-silicon
Off topic: nice, retro website look!
Back in the day, I studied Z80 assembly to write something about Pokémon red. I didn't realize it was this old
This is the CPU that I first learned to code on, first in TI Basic (TI-8[1356] ftw) and then Z80 assembler. Crazy to think that the CPU was "old" when I started, and it's still doing good work in those calculators even 20+ years later.
No 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 to learning Z80 assembly however. I printed a whole manual about Z80 assembly programming for the TI-84 Plus and started reading it but never wrote a single line of assembly for it. Yet.
Same here (actually had a voyage 200, but same same I guess). It's actually quite insulting that TI kept (and keeps?) selling waaay outdated hardware at horrendous prices. It's the SAP/Oracle business model applied to school hardware.
My son programmed a Z80-based instruction set into a Juno probe sensor. Still kicking.
The Z80 stopped being manufactured last year unfortunately
There are plenty of open core alternatives that replicate the architecture and ISA. Many of these are cycle accurate. Some have been tape-out proven. Hobbyist retro-computing enthusiasts who wish to build a Z80 system still have options even once new old stock and recovered CPUs become scarce.
There are clones, and updated packages these days like the EZ80, but they're not the same and they don't have the easy-to-use DIL form-factor.
Still I've always loved the z80, since my first computer the ZX Spectrum. Even now I play with z80 assembly now and again (mostly for CP/M retro-use).
My first computer was a soviet clone of a ZX Spectrum, which started it all almost 40 years ago...
Two 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 that handle the address and data bus. So, as soon as you make the request, the Z80 loses all access to its memory and data -- mid cycle. Which, you know, can be Bad. Radio Shack labels this pin TEST and uses it for internal testing. But it was definitely a bit of a disappointment to my Fathers efforts.
The second one is when I learned that the Game Boy Advance has a Z80 built into its chip. The designers drag and dropped a Z80 core (tweaked for GB) just so they could run legacy GB games on it. It just kind of bends your view of the computing world when something as significant as a Z80 can just be shoved into the corner of a die for "just in case" functionality.
Just shows how far we had come at the time.
I still remember clearly sitting down to play with the TRS-80 at the local Radio Shack in the 1970s
Unlike anything I had ever experienced, it was life changing, I would bike to the store every day after school
Family couldn't afford the computer but I bought all the books and would read them at home over and over and gawk at all the accessories in the catalogs
Then family surprised me with it as a birthday present with all the relatives paying for it, pretty sure I was the only person in town with one, even the school didn't get one for years
Didn't have any way to save programs, not even the cassette recorder which was too expensive, had to memorize them and retype every time I turned it on
Happy 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"!