Starting out

[electricdream]

I haven't really organised my thoughts very well so I apologise for this question being so nebulous.

I've programmed a little bit of 6502 for NES and Apple IIe. Graphics programming is fun and all, but I'm interested in going even lower. I'm becoming enamored by old school stuff like the AIM-65 or some of the ideas found in Rodnay Zaks 6502 Applications book.

I'm a little overwhelmed with where to even start. I'm guessing I should acquire a 6502, breadboard, and a few other bits(pun intended) and pieces. What is a realistic starting place? I don't expect my first project to be a working AIM-65 clone, but I'd like to achieve something practical. What are the first few pieces of hardware I should invest in? Where would I find them for sale? Is there a better or more modern approach/learning trajectory than the previously mentioned Zaks book for diving in?

I've tried nothing and I'm out of ideas.

Thanks in advance.

[GARTHWILSON]

electricdream wrote:

What is a realistic starting place? I don't expect my first project to be a working AIM-65 clone, but I'd like to achieve something practical. What are the first few pieces of hardware I should invest in? Where would I find them for sale? Is there a better or more modern approach/learning trajectory than the previously mentioned Zaks book for diving in?

Start with the 6502 primer. I recommend going through the whole thing, as it was written to answer the questions and problems that kept coming up over and over on this forum in its early years. It gets frequent updates. It's in 22 logically organized chapters.

[BigDumbDinosaur]

electricdream wrote:

I've programmed a little bit of 6502 for NES and Apple IIe. Graphics programming is fun and all, but I'm interested in going even lower. I'm becoming enamored by old school stuff like the AIM-65 or some of the ideas found in Rodnay Zaks 6502 Applications book.

As Garth suggests, read through his 6502 primer first. You will be able to glean a lot of information from it.

You didn’t mention your skill level with electronics. Are you looking to design and build something from scratch or purchase a working unit from someone else? If the latter, are you interested in a fully-assembled and tested unit, or are you willing to assemble from a pile of parts and a circuit board? Do you have the skills needed to do board-level assembly work, i.e., placing and soldering parts? The answers to these questions might help you make appropriate choices in how to proceed.

Lastly, you should add your location to your forum profile so others will know about where you are in the world and perhaps be in a better position to offer help when the need arises, especially in regard to sources for parts.

[electricdream]

GARTHWILSON wrote:

Start with the 6502 primer. I recommend going through the whole thing, as it was written to answer the questions and problems that kept coming up over and over on this forum in its early years. It gets frequent updates. It's in 22 logically organized chapters.

Thanks, reading through now. It certainly does seem to anticipate many of my questions and concerns.

BigDumbDinosaur wrote:

As Garth suggests, read through his 6502 primer first. You will be able to glean a lot of information from it.

You didn’t mention your skill level with electronics. Are you looking to design and build something from scratch or purchase a working unit from someone else? If the latter, are you interested in a fully-assembled and tested unit, or are you willing to assemble from a pile of parts and a circuit board? Do you have the skills needed to do board-level assembly work, i.e., placing and soldering parts? The answers to these questions might help you make appropriate choices in how to proceed.

Lastly, you should add your location to your forum profile so others will know about where you are in the world and perhaps be in a better position to offer help when the need arises, especially in regard to sources for parts.

I think it would be fun to build from scratch, but I may be overestimating myself. I suppose it's fair to say I have no skill with electronics. I have a vague and childlike understanding of what a resistor and a capacitor do.

The most electronic thing I've done is solder a a jumper on an electric guitar's pickups selector. I tried to build a guitar pedal from a kit, but somewhere between impatience and an old, corroded, much-to-large-tip soldering iron I botched something. I think it was probably sloppy soldering on the switch - a tiny square fellow that had something like 9 legs placed incredibly close together.

The pedal was form a kit with a PCB and all the parts. I didn't have trouble placing parts save for trouble seeing those tiny bands on the resistors and figuring out which way the IC was meant to plug into the socket. Then again, the proof is in the pudding. And my pudding didn't work in the end.

I tend to be ambitious and I'm starting to get the impression maybe I'm too ambitious going for building a computer at this stage of the game.

[BigDumbDinosaur]

electricdream wrote:

I suppose it's fair to say I have no skill with electronics. I have a vague and childlike understanding of what a resistor and a capacitor do...I tend to be ambitious and I'm starting to get the impression maybe I'm too ambitious going for building a computer at this stage of the game.

Well, given that, I’d say if you are intent on learning the 6502 assembly language, you should start with a simulator. My recommendation would be the Kowalski simulator, which includes a source code editor and macro assembler, and is something that is used by several of us here, including me. The simulator accurately simulates the NMOS 6502 and the modern 65C02, and includes an I/O console for testing. I think that would be a good starting point without having to have physical hardware.

As for building something, you do need a certain amount of practical skill. You obviously will need to work on your soldering skills before diving into hardware construction.

[BigEd]

Welcome, electricdream!

The reference section of this very website has many resources, too, including a page listing many emulators, both for desktop use and running in-browser:
In the Development Tools section, Generic 6502 Emulation, Simulation and test suites

There are also, of course, many emulators of specific 6502 platforms, both for desktop and for web.

For a beginner, I'd recommend easy6502. It's built for the learning process, not for major projects, so you'd expect to graduate from it. I do still use it to test little snippets.

[electricdream]

BigDumbDinosaur wrote:

Well, given that, I’d say if you are intent on learning the 6502 assembly language, you should start with a simulator. My recommendation would be the Kowalski simulator, which includes a source code editor and macro assembler, and is something that is used by several of us here, including me. The simulator accurately simulates the NMOS 6502 and the modern 65C02, and includes an I/O console for testing. I think that would be a good starting point without having to have physical hardware.

As for building something, you do need a certain amount of practical skill. You obviously will need to work on your soldering skills before diving into hardware construction.

The Kowalski sim is really interesting. I suppose one of the benefits of using it instead of my current emulator is that it's not platform specific. There are a few quality of life improvements over the way I've been coding. Thanks for pointing it out.

This is my catch-22: No skills to do real projects, but no projects to learn real skills . I think maybe I need to get Electronics Projects for Dummies and come back to the forum when I've learned something.

BigEd wrote:

Welcome, electricdream!

The reference section of this very website has many resources, too, including a page listing many emulators, both for desktop use and running in-browser:
In the Development Tools section, Generic 6502 Emulation, Simulation and test suites

There are also, of course, many emulators of specific 6502 platforms, both for desktop and for web.

For a beginner, I'd recommend easy6502. It's built for the learning process, not for major projects, so you'd expect to graduate from it. I do still use it to test little snippets.

Easy6502 is great! That was one of the sites I found early on in my journey. I keep it bookmarked because, as you say, it can be convenient to try out or disassemble a quick piece of code.

[Paganini]

Welcome, electricdream

electricdream wrote:

I think it would be fun to build from scratch, but I may be overestimating myself. I suppose it's fair to say I have no skill with electronics. I have a vague and childlike understanding of what a resistor and a capacitor do.

You are not too far behind where I started from, two or three years ago. I know a lot more than I did then, but I still have a long way to go! A good resource for the very basics is https://www.allaboutcircuits.com/textbook/

If you carry on, sometime soon you will encounter Ben Eater (https://eater.net/), so it might as well be now. I personally like Ben's videos. They make this stuff seem attainable to a hobbyist. However, there are some just criticisms of them too. (For example, he covers breadboard parasitic capacitance and decoupling in a grand total of one whole video. I think his 6502 breadboard computer has exactly 3 decoupling capacitors!) Anyway, they are a great starting point; just be aware that Ben is able to gloss over some important things because of his very low clock speeds (1 - 2 Mhz) and by using 74LS series logic ICs.

[HansO]

I can recommend the PAL-1 kit, available on Tindie.

Cost effective clone of a KIM-1, easy to expand with available add-on kits. Enthousiast and beginner friendly users.

[adrianhudson]

I am going to reccommend Ben Eater's 6502 series on YouTube too. Watch the whole "build a 6502 computer from scratch" series - BUT don't build it. Well, I don't recommend building it - at least not on breadboard. Ben has a particular knack with breadboard that seems to elude many others. Watch it over and over till you understand exactly what is going on.

THEN, when you are ready to progress, read Garth's primer. It will fill in all the detail. It will also point you in the right direction for building something. I refer to it over and over.

(If you want to look under the covers at how a computer actually computes - at least at a superficial level - watch Ben Eater's 8-bit computer series too.)

((p.s. if you do build Ben's 6502 the BUY GOOD BREADBOARD - not Chinese rubbish from Ebay (you won't find any good stuff on ebay - so speaks someone with experience!!)) - better still buy Ben's kit.

[Paganini]

If you want to build the Ben Eater 6502 but skip the breadboards there are a couple of PCB versions out there. TEBL has one on PCBWay.

I went a different way: instead of building Ben's 6502 on breadboards I built an RC6502 without its Arduino sidekick. It's modular and a little more customizable than the Ben Eater breadboard 6502, but I was able to use Ben's Arduino bus monitor for some early troubleshooting. After the first few steps, Garth's primer got very useful, especially when I went to wire-wrap a custom I/O card for the LCD display.

[HansO]

Paganini wrote:

If you want to build the Ben Eater 6502 but skip the breadboards there are a couple of PCB versions out there. TEBL has one on PCBWay.

I went a different way: instead of building Ben's 6502 on breadboards I built an RC6502 without its Arduino sidekick. It's modular and a little more customizable than the Ben Eater breadboard 6502, but I was able to use Ben's Arduino bus monitor for some early troubleshooting. After the first few steps, Garth's primer got very useful, especially when I went to wire-wrap a custom I/O card for the LCD display.

Also a good PCB design: https://github.com/bolwire/BenEater6502PCB

[Paganini]

HansO wrote:

Also a good PCB design: https://github.com/bolwire/BenEater6502PCB

Wow, I really like all those headers next to everything so you can get at all signals. That is a cool idea.

[plasmo]

Another hurdle for working with real hardware is the need of an EPROM programmer. It is a specialized $60 equipment only useful for retro computing. Newcomers are justifiably reluctant to get an EPROM programmer, not knowing whether retrocomputing is something they really want to do. I have designed a 6502-based EPROM programmer to address this reluctance, but after some experiences and thoughts, I think buying a commercial programmer (TL866ii comes readily to mind) is the easiest way forward. Unfortunately it is a significant mental block to overcome.
Bill

[adrianhudson]

plasmo wrote:

Another hurdle for working with real hardware is the need of an EPROM programmer. It is a specialized $60 equipment only useful for retro computing. Newcomers are justifiably reluctant to get an EPROM programmer, not knowing whether retrocomputing is something they really want to do. I have designed a 6502-based EPROM programmer to address this reluctance, but after some experiences and thoughts, I think buying a commercial programmer (TL866ii comes readily to mind) is the easiest way forward. Unfortunately it is a significant mental block to overcome.
Bill

I made my own eeprom programmer initially but it was slow and inflexible. It worked but I am very glad I bought one (TLS866II).
.