The History of Zilog & Z80

Comments · 401

• CO

  @Co-opSource · 2 years ago (edited)

  My dad was the CFO at Zilog for a while and we used to play racketball with Federico on occasion. Super nice and very smart man. OG engineer

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• MI

  @MichalKobuszewski · 2 years ago

  We hobbyists won't let the ol' Z80 die that easily. I'm working on a Z80-based computer with 512K of paged RAM, full bells and whistles like Ethernet, MIDI, OPL2, SD card, 800x480 LCD, serial, PS/2 and more to come. It's just executing NOPs at the moment while I am waiting for the Flash programmer to show up, and will not stop until CP/M and Zork are running! :)

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• BA

  @barryschalkwijk9388 · 1 year ago (edited)

  It's quite crazy how so many retro videos feature the Zilogs heavy hitters but the company itself is like ignored completely. Thank you for making this!

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• DO

  @donnieweston3249 · 2 years ago

  I must say that I have come to the conclusion that your channel is my top retro tech YT channels.  Your topics, commentary, detail and humor are spot on.  I find myself rewatching your videos more and more other as I pick up on details I missed the first time.

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• RO

  @robertfindley921 · 2 years ago

  When I was in college, the first thing you did for any project was grab a Z80.

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• DE

  @deechvogt1589 · 2 years ago

  Z-80 + CP/M will always have a place in my heart.  I loved my Kaypro II Z80 at 2.5Mhz 64K of RAM and two 191K Single Sided Double Density full height 5 1/4 inch disk drives, CP/M 2.2.  Oh, those were the days.  Thanks for making this video.

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• SC

  @scottfranco1962 · 2 years ago (edited)

  Nice overview.<br><br>I used the Z80 from 1979 until about 1987. &nbsp;By then you could get 16 bit memory for the S-100 bus, and 24 bit addressing. I used a homemade bank selector to access the extended memory, and had a 256kb card for the machine. When the Z280 came out, I moved to that. It was a 16 bit Z80 compatible CPU with a highly extended instruction set, and I made (and sold) an adapter that plugged that into a standard Z80 socket. The Z280 also had a memory pager built in, so that addressing 256kb in 4kb pages was possible.<br><br>Turned out the Z280 was buggy, and I ended up working for Zilog to try to fix some of the bugs. We spun the chip with a series of fixes, but it turned out the fundamental bugs were masking bigger and more serious bugs in the chip, and the CEO cancelled the chip. It now lives on as the EZ80, but I learned my lesson and headed on to the 80386.<br><br>What you are referring to as the Z800 became the Z280. The original design had a lot of problems, so you can&apos;t really say they ignored it as much as it had fundamental design issues and they canceled the project. Then it came back as the Z280, and got cancelled again, then came back yet again as the EZ80. However the EZ80 was not compatible with the Z280, so there you go.<br><br>You can still get the Z80 in the form of more advanced chips, and the &quot;death of the Z80&quot; headline was somewhat inaccurate. Yes, they discontinued an obsolete form of the chip, but there are many other instruction compatible versions. I think the most sensible design is to use one of several FPGA versions of the Z80 instruction set. Then you can use a relatively cheap FPGA with a Z80, several peripherals, and a chip with 100&apos;s of I/O&apos;s to boot.

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• IA

  @ian_b · 2 years ago

  I find it interesting that at that time, all the CPU manufacturers thought creating new products meant new architectures, so the Z800 and Z8000 were completely new designs nothing like the Z80. It turned out that the way forward was evolutionary with extending present architectures, as with the x86 line. Code compatibility and developer familiarity were way more important that radical new architectures (as Intel themselves discovered with iAPX432 and Itanium).

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• LU

  @lucaguarnieri8807 · 1 year ago

  I LOVE this man. He talks for hours about asssembly, the history of Unix workstations, Sun, VLIW, Sparc,,,,,, and then he act surprised when he discovers we ALL are into nerdy stuff.

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• LE

  @leeselectronicwidgets · 2 years ago

  While the biggest slice of the pie in the retro computing days goes to the z80 and 6502, the 6809 also had a look-in too...<br>The z80 is also used in loads of early digitally controlled synths too (as was to a lesser degree the 6809, but never the 6502, weirdly)

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• MO

  @MoreFunRetro · 2 years ago

  Brilliant episode! Probably my favourite CPU. A real marvel that it&apos;s still relevant all these years later.

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• BI

  @BitwiseMobile · 1 year ago (edited)

  The first computer I laid hands on was a Kaypro II at my high school in 1985. &nbsp;My uncle, who was a professor at UCR, came over one day and brought his TRS-80 Model 100. &nbsp;That weekend with that computer changed my life. &nbsp;I will always have a place reserved in my heart for the Z-80. &nbsp;It powered the machines that started my life&apos;s journey. &nbsp;Those machines were the portal to a new world that suddenly made sense to me in a world that was confusing and stressful. &nbsp;I could code for hours and not think of anything but the code. &nbsp;It was the greatest escape ever and it eventually led to my career. &nbsp;I later moved on and learned 6502 assembler and then 8088 assembler when my step-dad bought a Leading Edge Model D to help him track his stamp collection. Little did he know I was going to make that machine mine :D<br><br>Edit: &nbsp;Apparently the TRS-80 Model 100 was powered by an Intel chip. &nbsp;Who knew *shrug*. &nbsp;I did use the TRS-80 though, which is a Z-80 powered system, when I took VisiCalc in high school trying to get qualified for computer classes at the college.

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