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The Z80 Mem­ber­ship Card (2015)

sunrise-ev.com

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Re: The Z80 Mem­ber­ship Card (2015)

#21

Post by f1shy »

alnwlsn wrote: post #11

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:…

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.

Re: The Z80 Mem­ber­ship Card (2015)

#22

Post by alnwlsn »

f1shy wrote: post #21
alnwlsn wrote: post #11

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:…

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.

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

Re: The Z80 Mem­ber­ship Card (2015)

#23

Post by wpm »

wkjagt wrote: post #12
alnwlsn wrote: post #11

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:…

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 :-)

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.

Re: The Z80 Mem­ber­ship Card (2015)

#24

Post by Gracana »

JKCalhoun wrote: post #15

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…

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.

Re: The Z80 Mem­ber­ship Card (2015)

#25

Post by sowbug »

wkjagt wrote: post #12
alnwlsn wrote: post #11

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:…

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 :-)

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://web.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!

Re: The Z80 Mem­ber­ship Card (2015)

#26

Post by ranger207 »

wpm wrote: post #23
wkjagt wrote: post #12

Earlier quoted context omitted.

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 :-)

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.

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

Re: The Z80 Mem­ber­ship Card (2015)

#27

Post by SilentM68 »

alnwlsn wrote: post #11

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:…

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 :)

Re: The Z80 Mem­ber­ship Card (2015)

#28

Post by billforsternz »

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.

Re: The Z80 Mem­ber­ship Card (2015)

#29

Post by boxerbomb »

mikkupikku wrote: post #17

Very cool. My version of this years back was a TI-83+ I learned asm on.

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.

Re: The Z80 Mem­ber­ship Card (2015)

#30

Post by MomsAVoxell »

citizenfishy wrote: post #20
alnwlsn wrote: post #11

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:…

I have very sadly done the same with ZX Spectrums but the quest is never ending due to all of the baltic clones

Same here but Oric-1/Atmos.
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