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I'm wondering if it is possible to buy an sort of device currently in production that uses a z80 compatible CPU - not an FPGA.

I don't want to build a kit or use a soldering iron. I'm also looking for something that is commercially produced rather than a hobby device designed and sold by hobbyists to other hobbyists.

When I say reasonable cost well I guess in the domain of $50 to $80 since the chips cost around $18.

I've searched fairly extensively and there's not much it would seem. The more peripherals the better and bonus points if it had some sort if display output and GPIO.

Ideally something that uses a "modern" Z80 variant such as the eZ80 which runs at 50Mhz.

Anyone seen anything along these lines? I've seen the Ti 84 calculators but it appears the operating frequency of these are severely constrained which means I wouldn't be able to run it near the eZ80 50Mhz maximum clock speed.

Brian Tompsett - 汤莱恩
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Duke Dougal
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  • I haven't used one, a complete set is way outside of my price range, but there is https://www.tindie.com/products/lutherjohnson/makerlisp-ez80-lisp-cpm-computer/. Where it falls on the hobby/commercial line is up to you, but it's far from an RC2014-style thing with that high-density board-to-board interconnect. – Thomas Jager May 25 '20 at 01:08
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    The TI-84 Plus CE runs an eZ80 at 48 MHz, which is pretty close to 50. They're outside your price range, though, at least in Europe. – Michael Graf May 25 '20 at 10:49
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    I'm not sure your reasonable price range is. Typical markup for components → commercial device is 3×. So if an eZ80 is $18 and your range is $50-80, you're only allowing a component cost of $16.70–26.70. Your CPU is taking ⅔ of that maximum, and still you need RAM, ROM, logic, interfaces, circuit board, case … – scruss May 25 '20 at 13:22
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    @MichaelGraf Unfortunately the only ez80's you'll find nowadays are SoCs or microcontrollers. At least, I couldn't find any "true CPU". Would love to be proven wrong. – mid May 25 '20 at 20:56
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    @mid So what's the problem? They (at least the ones I've checked) still have the complete system bus (address, data, control) available externally, so you should be able to hook up whatever you want. Besides, the original question was for a complete system, "the more peripherals the better"... – Michael Graf May 25 '20 at 21:58
  • @DukeDougal I haven't investigated any of this myself. My most recent TI calculator is more than 15 years old (and my oldest over 40) :-) All I can tell you about the TI-84 Plus CE is that, according to all published sources I have seen, it's running at 48 MHz, and that "CE calculators revision M and later (manufactured on and after April 2019) contain a faster flash chip (Winbond 25Q32JVSIQ) than previous revisions, which contained a Winbond W29GL032C. Due to this change, more recent revisions have seen a significant improvement in overall speed." Is this the issue you're referring to? – Michael Graf May 25 '20 at 22:29
  • @DukeDougal: have you seen the MakerLisp:https://www.tindie.com/products/lutherjohnson/makerlisp-ez80-lisp-cpm-computer/ ? it seems to fit your bill, and is in a similar price bracket. They say it runs CP/M as well as Lisp, but it's still a eZ80, so you can just make it do whatever you'd like – Shane Gadsby May 25 '20 at 22:49
  • @MichaelGraf more information here about the performance and wait states, quote: "the TI-84 Plus CE Revision M and the TI-83 Premium CE Edition Python (which I'll refer to as the EP) has a different FLASH storage chip from the original TI-83 Premium CE (83PCE) and TI-84 Plus CE (84PCE). This means that the EP's FLASH storage is faster and has only 1 wait state (unlike the 9 wait states on the 83PCE and 84PCE). Therefor the FLASH 5 times faster than the 83PCE and 84PCE causing the OS to run 2 times as fast!" https://www.cemetech.net/forum/viewtopic.php?t=14663&start=0 – Duke Dougal May 26 '20 at 00:02
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    What is your use case? What are you looking to do with such a machine? Most folks using these today are simply hobbyists that enjoy the electronics and interfacing side, or folks trying to run original software (mostly games). – Will Hartung May 26 '20 at 04:25
  • Vandalising ones own Question is quite a thin skinned aggression. Wouldn't it be more appropriate to work out why the question is seen by several active members around the globe (none of them a moderator) as looking for improvement? – Raffzahn May 27 '20 at 07:23
  • Please delete this question - either it is not suitable for the site or it is suitable. You can't have both and you don't have my permission to publish it if it is closed as not suitable. Delete the question please. – Duke Dougal May 27 '20 at 08:30
  • @Raffzahn you insulting me is so typical of stack exchange toxicity - yuck awful community. – Duke Dougal May 27 '20 at 08:36
  • @DukeDougal the process for non fitting question is to be closed, not deleted. Please calm down an maybe explain were I have insulted you. Belive me, I'm sorry if I did, but so far I don't see an insult. – Raffzahn May 27 '20 at 15:06

2 Answers2

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Bill's MinZ180 is tiny, fast, fully assembled, and falls within your price range.

MinZ180.

He may have one or two left, I'm not sure.

scruss
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It sounds as if your ideal device would be something like a Raspberry Pi, but based on a Z80 rather than an ARM core. The Pi provides a video generator, USB ports for peripherals, GPIO points, and so on. However, the reason Raspberry Pis are so cheap is that they're based on System-on-Chip products that are made in large volumes for other applications.

These days, I really doubt anyone makes Z80-based SoCs with video generators. Commercial applications of 8-bit microprocessors are for smaller and simpler tasks than running a display to modern standards. But there are other ways to get the experience you seem to be after.

The easiest is to buy a Pi and run a Z80 emulator on it. There are several available, including at least one that boots directly on the Pi, without needing the Pi's usual OS as a host. This will run much faster than historical Z80 hardware.

Another way is to make contact with your local maker group or hackspace, find someone who enjoys building computers from kits, and get them to build a kit machine for you.

John Dallman
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