I'll add my 2 cents since I built my own SBC with the NMOS6502 in the center years ago tethered to a C-64...

Like Daryl's SBC, I think this board everyone is talking about should have the ability to program standard DIP EEPROMs in order to spawn other SBCs.

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65Org16:https://github.com/ElEctric-EyE/verilog-6502

I agree that having a goal is important. If there's no end result to strive for, motivation is quickly lost.

But that also implies that the machine should be capable enough. If there's no I/O except for a serial port or a LED, you can't pick many interesting goals. On the other hand, the board should not be overly complicated or expensive, so there's a challenge....

Thanks Simon - I think I'm more clear now that we must have an address bus and a data bus. Even if there's still some magic chip in there.
The Propeller might be the ideal magic chip, if the built in bootstrap is enough to allow the eeprom to be written over a serial port connection.
Cheers
Ed

Heh that made me realize that my Propeddle project should be able to program 28Cxxx EEPROMs to spawn other SBC's too

The 128K RAM chip that I use is pin-compatible with 28Cxxx so you'll be able to just "stick an EEPROM on there", and write a simple Propeller program using the Propeddle library to download a binary file from the serial port to the EEPROM, with a little help from the Parallax Propeller Tool to integrate a binary image into the program, and a little help from the 65C02 on board the Propeddle which serves as address generator.

For the purists, it should even be possible to program an EPROM this way, after a small modification to make it possible to apply the programming voltage. I will keep that in mind when I design the next PCB.

===Jac

Great!
Because buying a product is one thing, but making ones very own SBC for the first time... there is no other feeling like it in the world when it runs successfully for the first time!!!

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65Org16:https://github.com/ElEctric-EyE/verilog-6502

I agree. The way that my project does this is that it can provide major functionality in the minimum configuration: the Propeller takes care of video, keyboard and emulated I/O, including emulated mass storage devices. It doesn't have any VIAs, PIAs or CIAs on board but they are easy to emulate. There is an expansion bus that can be used for connecting real I/O chips.

===Jac

Thanks Simon for a very well written post from someone who's actually in the process of getting into 6502.

With so many others already making boards, I'm not planning on making another one myself so far, but if I were to do one, it would have room to put more I/O, so when the user decides it becomes necessary or affordable, the board is already ready for him to add the ICs and connectors. My workbench computer with 80+ bits of I/O, although it does not have video (as that's not what it's for), has far more I/O than any Pi or Arduino, and if/when I make another one for myself, it will have probably one more VIA. I've always needed to make board layouts really dense in my work, and although I would use only thru-hole for the kit builder, it would be much more compact than the 6502 board pictures I've seen online. Without making it any harder to assemble, basically all the empty space between ICs would be gone. See my page on Expansion Buses and Interfaces though on why not to run the processor's own buses off the board, and why it's not necessary to either.

As for goals: I wasn't exactly a 6502 beginner when I made my workbench computer—although I've learned a lot since then—but I started out with ideas of what I wanted it to do, based on experience, and tried to look ahead—not that I could see the unforeseeable, but I was trying to keep from painting myself into a corner. It has worked out very well, and I have added quite a lot to it over the years. I had visions of building another one with more of everything even 15+ years ago, but finding ways to improve it has breathed new life into it, delaying the need for another.

BTW, Simon, on the terminology, for future reference, "CIA" stands for "complex interface adapter" and is the 6526, a totally different bird from the ACIA, or asynchronous communications interface adapter, which is the 6551.

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http://WilsonMinesCo.com/ lots of 6502 resources
The "second front page" is http://wilsonminesco.com/links.html .
What's an additional VIA among friends, anyhow?

Oops! Thanks, I better go update my blog posts on my project

EDIT: I had it right in those actually. Need to fix the comments in my source code though!

I did just have another thought. How do we define a beginner? I am new to 6502 computer building although this is actually my second one. I am new to 6502 assembly programming but I am a software engineer by trade (actually in QA/testing now though). And I am not an electronics engineer but I have tinkered for years and know enough to get into trouble.

Do we assume a total newbie knows nothing about coding or electronics or soldering to start with? What level of understanding would it start from? What concepts are needed to be understood first? Or is it safe to assume if someone is looking for specifically building a 6502 machine they must have some idea about them to start with?

Simon

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My 6502 related blog: http://www.asciimation.co.nz/bb/category/6502-computer

I make spell out some assumptions in the intro page of the primer, but those are not hard and fast rules of course. That's a pretty fuzzy area, and everyone will be coming in from a slightly different angle. In my case, I was interested in analog long before I was in computers, so from the initial introduction of something like a NAND gate, I could immediately imagine and draw up a circuit diagram to make such a thing from discrete transistors and other parts.

If you know of a good primer web page to introduce the newbie to the things that I spelled out as assumptions, IOW, for someone who is not even that far along, I would like to link to it. The info is all over the internet of course, but I expect that finding the ideal page could take a lot of time.

_________________
http://WilsonMinesCo.com/ lots of 6502 resources
The "second front page" is http://wilsonminesco.com/links.html .
What's an additional VIA among friends, anyhow?

Well, one idea would be to network with the other classic/retro platform sites like csdb, lemon amiga/c64, atariage etc etc (not forgetting the ones for the beeb/acorns and the apples) and also create a youtube/blog for the twenty somethings and younger

Also to network with the various emulation software sites like CCS64/winvice, Applewin, Atari++, Altirra, Stella/PCAE etc and work with them to popularise their work on the likes of youtube/blogs etc...After all youngsters i am assuming are into the whole yootoob thing and blogging (not forgetting twatter as well)


I appreciate that the majority of people here prefer pucka (as in real) hardware to work with (in regards to 6502 work/projects etc),. thing is since emulation is free, it's a quicker and easier way to get to young people...their not spending 30/40/50 pound on some xbox or ps3 cack, they are playing around with an emulator which hopefully they will learn something from (like programming or doing a simple basic game)

Seeming as though we have some programming genius's here (of the modern type) perhaps some of you could cobble together an 'Official' 6502.org 6502 and compatibles emulator...Or even better something similar to mednafen or M.E.S.S but for 6502 computers (i.e. Atari, Acorn, commodore, Apple, Oric and the single board jobbies as well like Aim65/SYM and Kim1)

Something interesting i found out though, Apparently the designer of the most successful upscale 6502 processor (Bill Mensch) namely the 65816, also had a hand in developing/designing the original version of Acorn/ARM ARM processor (the one used in the first BBC/Acorn Archimedes), their was a good reason why he didn't offer Acorn the 65816, because he'd already offered and given exclusivity to Apple to use the processor in the IIgs...So there's a little bit of 6502 in the Acorn Arm processor...as now used in things like Ipad/Iphone etc)

If you want to go this route, I can offer the source code to DarcNES (an older multi-system emulator that included support for the apple ][). It's been ages since I did anything with it, and it might well turn out to be junk not worth using, but I should still have the source code for a recent version, even if I did accidentally torch the source control repository about a decade ago...

Some of the simulators avaialbe are shown and linked at http://www.npsnet.com/danf/cbm/cross-de ... #Emulators. (Most of these are simulators, if I may be a purist here, meaning software only.)

_________________
http://WilsonMinesCo.com/ lots of 6502 resources
The "second front page" is http://wilsonminesco.com/links.html .
What's an additional VIA among friends, anyhow?

As you mentioned, we're up to our armpits in simulators and emulators. If someone wants to go that path, then it's readily available, on most any platform.

There's a lot of value to developing on a simulator, simply because you can get better insight in to what's wrong with your code vs a build/burn/bust cycle of developing on raw hardware.

That said, this site stands out, IMHO, as the premier site that talks about 8 Bit hardware, and working with hardware.

The 6502 is interesting because of it's hardware, rather than in spite of it like many other chips. Nobody really "liked" the architecture of the x86. They just accepted it, and worked around it. For whatever reason, there isn't a "z80.com", or "6809.com" that offers a similar community like this one, despite the ubiquity of the Z-80 or the cleverness of the 6809.

As an example, we get remarkably little Apple/Atari/C64 traffic here. There's some, sure, it's inevitable, but we don't talk about games or classic software or any of that here. There are dedicated sites for those systems, of which very little is actually dedicated to hardware. No, here, it IS about hardware, and the novelty and uniqueness that the 6502 brings to the processor world. The Hardware topic is the largest topic on this forum, and Programmable Logic is in a close race for 3rd place alongside Programming and behind General.

So, any effort that comes from this site, me thinks, is going to be, and should be, hardware. Something that helps portray the fundamentals of micro processor operation and interfacing. There may be some "magic" chips that make the rest easy to use, but the core is the CPU, and the magic within it. And pushing buttons and making things happen is Interesting. It was interesting as a child with a water fountain, it's interesting still today. Understanding the heartbeat of such a system is as important as the limbs and servos, especially because the core is so self contained today.

Interesting that you say that (i.e. that there's v. little interest in this site by Atari/Commodore users) since i would have thought that along with Apple as well as Atari and 8/16bit Nintendo desktop game systems, that in itself forms the majority of the 6502 user base and therefore the target market/audience for this site (unless I am clearly missing something, which i probably actually am)

I think what Whartung was saying (and I agree) is that many vintage computer enthusiasts come to this place to discuss the lowest level: how the 6502 works internally, how to build your own computer using the information from Garth's webpages, meet others who have already done such a thing etc.

I bet most people on this forum have worked with Commodores, Apples, Ataris and Nintendos at some point in time, but at 6502.org, I get the feeling that all the differences between those systems (differences between specific hardware and differences in opinion about how good or bad they were) are tossed aside. This website is about the 6502 and related CPUs, and most of the time we don't get distracted by the non-important stuff.

While there has been much discussion in this thread that I've enjoyed following and contributing to, I'm sensing that everyone still agrees on the basic issue: We would like to provide 6502 newbies with something that they can use to build their own 6502-based system, that preferably has a real processor, can do something useful, is not too expensive and should consist of components that are available at websites such as Digikey, Jameco or Mouser.

Some newbies may want to try emulators first, but they probably end up here when they're ready to build some hardware, or use some pre-built hardware that's not a vintage system from eBay. In the last 2.5 years that I've been working on my project, I've been getting enough attention that it makes me feel that there are a lot of people who would be interested in learning (or teaching!) about basic CPU technology that manifests itself in the 6502. And because my project does the bitbanging of the 6502 pins from a Propeller, it goes one step further and potentially gives students a look at what happens at the pin/cycle/datasheet level -- if they're interested.

I remember when I was 15 or so years old, I figured it wouldn't be too hard to build my own computer. I read about self-build projects like the Elektor Junior but it was simply too expensive and I couldn't think of a use for a computer so I never had one or built one. But I remember how much those books and articles made my hands itch to make something myself, even if it was just to show it off to my parents, family and friends. If it would have been possible back then to build a $50 computer kit that would have started out with no code at all but I could make it do whatever I wanted it to do, I might have gotten one just for the heck of it.

Maybe not all newbies will eventually buy a project (in kit form or ready-made); maybe some of them will buy a kit but will never build it. But for me, designing a kit and dealing with some of the technical aspects, sales aspects, and social aspects has been very educational, and I'm not even done yet. What matters is that eventually, we can pass on the sense of accomplishment that one gets when one builds their own computer from components, and makes it work. When I showed my grandkids that I have a Commodore 4032 now, they didn't even shrug, let alone make me pull it out and power it up to see how it worked. But I know they like soldering and tinkering and they enjoyed their visit to the Computer History Museum last year. And I'm pretty sure that, by letting them put one of my kits together, I can make them understand how I felt when I typed my first Basic program on a 4032 in school in when I was 12 or 13.

===Jac