[HN Gopher] Z80 Membership Card
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Z80 Membership Card
Author : exvi
Score : 94 points
Date : 2026-01-12 05:42 UTC (3 days ago)
(HTM) web link (sunrise-ev.com)
(TXT) w3m dump (sunrise-ev.com)
| b800h wrote:
| It's a shame Zilog stopped making Z80s. Presumably this means you
| can't make one of these from new components any more. Perhaps
| someone could create a new iteration of the same idea.
| lpribis wrote:
| The Z80 instruction set lives on via the eZ80, Z180 and others
| which are binary compatible with the original Z80 instruction
| set. Unfortunately Zilog stopped making the 40 pin DIP package
| a couple years ago so yeah this specific board will be hard to
| source. You can still find them on gray market, mostly ones
| that have been desoldered from existing boards.
|
| Even if you made a version of this board with the footprint
| changed to the QFP eZ80, it probably wouldn't work because the
| eZ80 has different memory mapping and clocking differences.
| 0xTJ wrote:
| The Z180 has however had its PLCC packages discontinued.
| Personally, I find SMD CPUs to not be appealing for these
| sorts of projects, even if the Z180 is a great chip.
| shakna wrote:
| You can probably put together something similar with A-Z80 [0]
| or a similar FPGA redesign.
|
| [0] https://github.com/gdevic/A-Z80
| alnwlsn wrote:
| Luckily so many were made, they will be around for a while yet.
| For years now you've been able to buy (recycled?) ones on Ebay
| or Aliexpress, and at a price much cheaper than the new ones
| sold for.
|
| It will probably be a decade or longer until those sources
| start to dry up, but even at that the Z80 will never become as
| rare as say, a SID chip.
| olivia-banks wrote:
| The Z80 is still used in consumer products. TI-80/TI-83
| calculators are a well known example.
| alnwlsn wrote:
| For the aspiring hacker, we've also got:
|
| The 80's/90's VeriFone Tranz 330 credit card terminal, which
| has a complete Z80 computer inside with DART, CTC and PIO
| chips, 32K RAM, and a socketed EPROM.
|
| The Cidco Mailstation, which has a Z80, sizable monochrome
| LCD, and full-ish size keyboard, perfect to hack into a
| TRS-80 Model 100 style laptop.
|
| You can pick up either on Ebay right now for ~$25
| acutesoftware wrote:
| Nice to see old tech revitalised - I had fun with the Australian
| version of a Z80 single board computer -
| https://en.wikipedia.org/wiki/TEC-1
| Barathkanna wrote:
| This is pretty eye-opening. It really drives home how simple the
| core control logic can be. Starting with toy cars or small-scale
| vehicles feels like a great way to teach and validate these ideas
| before layering on unnecessary complexity.
| unwind wrote:
| I think this is very cool, even though I have no historical
| connection to the Z80 it's of course a well-regarded and firmly
| entrenched/popular retro CPU.
|
| But this really is a stretch:
|
| _The Z80 Membership Card itself is a stand-alone single-board
| computer that can "power up" your projects, like the Parallax
| BASIC Stamps or Arduino microcomputers._
|
| Both of those are very commonly called _microcontrollers_ , not
| microcomputers, since they have all of those extra chips merged
| into the single package of the CPU.
|
| Take a look at the Arduino Uno [1] which is a very typical (if
| old) example: you will see that the board is not covered in ICs
| from edge to edge, since all of the main functionality is in the
| single-chip microcontroller. I think the second big-ish package
| visible is for the USB, but that also disappears on more modern
| controllers with on-board support for USB.
|
| [1]:
| https://en.wikipedia.org/wiki/Arduino_Uno#/media/File:Arduin...
| MomsAVoxell wrote:
| It's pretty clear that the design of the Z80 Membership Card is
| intentionally steered towards the micro-computer ethos. The
| distinction between a microcomputer and a microcontroller is a
| subtle one; in fact, it's up to the use-case whether either
| term is applicable. Microcontrollers do, indeed, provide lots
| of I/O and rudimentary computation capabilities - whereas
| Microcomputers have computing power, of a sort, and some
| facility for I/O which may - or may not be - expansive.
|
| So the stretch is not much more than a matter of semantics,
| imho. I've used Z80's as microcontrollers, I've also used them
| as microcomputers.
| assimpleaspossi wrote:
| fwiw, I have two Z80s--maybe more--in a box among all my other
| parts.
| alnwlsn wrote:
| I grew up in a world where the Arduino already existed, but it
| was not until I tried building homebrew Z80 computers like this
| that I really felt I understood how computers/processors work at
| the low level.
|
| Consider this a warning though: this hobby has caused me to
| involuntarily collect every model of Z80 powered TRS-80 computer.
|
| If you wish to become hooked anyway, this project might be
| another good place to start:
| https://hackaday.io/project/159973-z80-mbc2-a-4-ics-homebrew...
| wkjagt wrote:
| I went through the exact same process, but with the 6502 (Ben
| Eater's videos, and then another SBC of my own design after).
| It's helped me become a better programmer too. Example:
| pointers in C now feel very natural instead of some abstract
| idea of "memory addresses, whatever those are".
|
| And yep, I now also own many 6502 based computers :-)
| wpm wrote:
| Not having my 'a-ha' moment with pointers until years into my
| education when doing assembly made me wonder why we don't
| start with a half-adder and work our way up from there
| instead of throwing novices right into C++ or Java OOP with
| no context.
| ranger207 wrote:
| That's how my comp sci degree went at Georgia Tech. There
| was a data structures and algorithms class first that used
| Java but then 2110 was building a computer from the
| (simulated) transistors up. I would've never understood
| pointers or C in general otherwise lol
| sowbug wrote:
| I'm sure you already saw this, but in case others haven't:
| https://blondihacks.com/veronica/ is required reading for
| anyone into 6502. I was trying to rehabilitate a Cocktail
| Joust arcade cabinet I'd had in storage for years, and
| instead went off into a 6809 time warp for a while. Quinn's
| 6502 blog articles were helpful for inspiration while I
| breadboarded a really basic 6809 computer.
|
| I ended up giving away the Joust machine to a guy (https://we
| b.archive.org/web/20200709102945/http://www.robotr...) who
| had poured his heart and soul into Robotron disassembly and
| also was the Joust world-record holder in 1983, so I knew
| he'd appreciate it at least as much as I did. He happened to
| live in the area, and was more than happy to drive over and
| load it up. It's been 13 years since then. I hope he and it
| are doing well!
|
| Factoid: It takes about six hours to reach 10 million points
| on Joust. Christian's record was 98 million points!
| citizenfishy wrote:
| I have very sadly done the same with ZX Spectrums but the quest
| is never ending due to all of the baltic clones
| MomsAVoxell wrote:
| Same here but Oric-1/Atmos.
| f1shy wrote:
| What I do not like is using a uC that is almost as capable as
| the whole board as part of it.
|
| I know, you have to take a pragmatic approach... but feels like
| cheating... idk.
| alnwlsn wrote:
| The Z80-MBC (the original breadboard version [0]) was
| actually the second Z80 computer I built. I first tried out
| one of the Grant Searle designs [1] on a breadboard, and it
| worked!... for literally 8 seconds, then the single ACIA chip
| I had waited weeks to get died for no reason. But I didn't
| have any way to debug what was wrong.
|
| It also didn't help that I didn't have many EEPROMs or an
| EEPROM programmer at the time, but the ATMega32A can be
| programmed with an ordinary Arduino.
|
| [0] -
| https://hackaday.io/project/19000-a-4-4ics-z80-homemade-
| comp...
|
| [1] - http://searle.x10host.com/z80/SimpleZ80.html
| SilentM68 wrote:
| Loved TRS-80 PCs and the COCO in early to mid 80's. My real
| first PC digital hardware class used those machines. Like most
| people in those days, could not really afford to purchase any
| but was gifted a COCO. w/ Editor/Assembler for experimentation
| :)
| osullivj wrote:
| Love the Freak Brothers references; two US counter cultures that
| do cross pollinate. Z80MC RAM & ROM seem v generous compared to
| the ZX81 I used to cut my asm teeth, wobbly RAM pack and all...
| JKCalhoun wrote:
| Looks like the caption to the image references a "Creative
| Computing" cover from 1979--so an indirect FFFBrothers
| reference.
| JKCalhoun wrote:
| There's also an 1802 Membership Card--which I knew as the COSMAC
| Elf Membership Card [1][2]. Switches and LEDs. I built one of
| these kits a decade ago but mine didn't work. (I still need to
| pull it out and try to debug it. For all I know I did assemble it
| correctly and there is just a RUN switch or something I did not
| know to flip.)
|
| [1] http://www.sunrise-ev.com/1802.htm
|
| [2] http://www.cosmacelf.com/gallery/membership-cards/
| Gracana wrote:
| Nice, I clicked to see if anybody had mentioned "the original."
| I built one of those as well. It is a very cute little system,
| and the 1802 is simple enough that the little front panel is a
| somewhat usable interface.
| mikkupikku wrote:
| Very cool. My version of this years back was a TI-83+ I learned
| asm on.
| boxerbomb wrote:
| Spot on, programming on any of these TI calculators in either
| BASIC or ASM is a great way to learn programming and can really
| teach a programmer a lot about how computers work, and how to
| program efficiently. I still think that TI calculators could
| play an important role in computer science education. If you
| haven't checked it out already check out the Cosmac Elf
| memebership card and some of the Homebrew 1802 software and
| hardware, there is a lot of nice stuff.
| satiated_grue wrote:
| Here's some context on the RCA 1802 (COSMAC) Membership Card,
| also by Lee Hart at the same website, which is the real star of
| the lineup:
|
| http://www.retrotechnology.com/memship/memship.html
| billforsternz wrote:
| I love the Z80, I started my career writing Z80 assembly for
| various embedded projects on a Z80 host system 45 years ago.
|
| But you don't need a physical Z80 to enjoy that classic
| instruction set. For example see this source file from one of my
| projects;
| https://github.com/billforsternz/zargon/blob/main/src/zargon...
|
| The good ole' Z80 assembly code is right there unaltered on the
| right, but it executes using C macros. In my humble consumer
| laptop I get a 40,000 times performance boost compared relative
| to a colleague's physical Z80 running the same code. I love the
| combination of nostalgia AND modern hardware performance.
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