Picocomputer 6502

[BigEd]

Oh right, my mistake!

[BruceRMcF]

Rumbledethumps wrote:

... Lee Smith's video is about the 6502 CC65 IDE built around cmake and vscode. You can, of course, build 6502 code with any tools you like, I'm just focusing on making everything use the same tools. The Pi Pico code is all C too, not C++, so you can explore the whole stack knowing only one language that's not assembly. ...

A laudable goal, even if I would prefer if that one language was Forth. But as opposed to the 6502 side, Forth on the Pi Pico side probably still needs a little bit of C to bind external library calls.

Rumbledethumps wrote:

I'm here. Happy to answer questions, but I didn't see any. If I'm just expounding, I do it in code, the documentation, or a video. And I'm old enough to ignore the off-topic stuff.

Where is the access to the VIA GPIO on the board built by PCBWaaaay (or whomever), and what is the headroom like for access if the acrylic sheet case is attached?

[Rumbledethumps]

There's only one PCB layout right now and it has all the 6522 GPIOs exposed on J1/GPIO. Options for access include cutting holes or leaving the top off or designing your own case or using taller standoffs or a ribbon cable.

[BruceRMcF]

Rumbledethumps wrote:

There's only one PCB layout right now and it has all the 6522 GPIOs exposed on J1/GPIO. Options for access include cutting holes or leaving the top off or designing your own case or using taller standoffs or a ribbon cable.

For what I want, jumpers seem to be a good approach, so either cutting holes or a right angle block header are the approaches I would be thinking about.

[Jmstein7]

Rumbledethumps wrote:

Most of you have seen my project on YouTube. For the uninitiated...

It's a WDC 65C02 + 65C22 system with RP2040 chips running the video, audio, USB, and operating system. It can be built on a breadboard or on a PCB with 100% through hole construction. For some, it's a starting point for hardware experiments. For others, it's a complete system to explore programming.

Here's the full playlist:
https://youtube.com/playlist?list=PLvCR ... XNmNJLVM2r

Everything is Open Source. You can build it yourself, or have it built in China.

I've seen some of your videos. Very cool ideas.

[BillO]

Sorry, but I do not want to come across as being negative here, and maybe this is just another symptom of the inevitable ossification of my brain but I honestly do not understand the idea behind this project. It seems the RP2040 has enough horsepower to emulate the 6502 as well as the other tasks assigned to it and probably do it a darn sight faster too. Why bother tacking on the old iron at all and incurring all that extra cost, time and real estate?

Again, sorry for this but I am honestly confused by the effort even though it seems quite successful.

An analogy that sprung to mind is building a car and using a dual turbocharged variable valve timing V6 to charge the battery, run the AC, the stereo, the power brakes, locks and steering, etc. and as a starter motor, fuel pump and fan for the engine which will be a B&S 192cc side valve single.

Other than that it looks like an awesome project.

[Rumbledethumps]

If all you can think of are things that can be done with emulation, stick with emulation. Or just write it native.

If you want to learn about and tinker with real hardware, the RP6502 chipset is a strong foundation. You could, for example, drop the Pico VGA and design your own VGA system. Or do experiments with DMA. Or load it up with real SIDs and OPLs for some monster music. The Picocomputer 6502 reference design with its single 6522 is only an example of what's possible. It's a toy computer for 6502 hobbyists. It's fun, affordable, educational, and visceral.

In your car analogy, does the twin turbo cost next to nothing? The Pi Pico is $4 while a W65C02S is $10. And why build a car at all when you can take the bus or a taxi or an airplane? Why go anywhere at all when you can see other places on TV, work from home, and get your food delivered?

[BigEd]

> I honestly do not understand the idea behind this project

That's a good way to put it. The project makes complete sense to me. But having written on this topic several times before, I don't feel motivated to go through it again - I think it's up to you, to read more and think about what the motivations might be, or to shrug it off as differences in preferences, and move on.

I don't much like it when project threads are peppered with comments asking why the project exists. The answer, of course, is that someone thought it interesting and worthwhile. They don't owe anyone an explanation.

[barrym95838]

Rumbledethumps wrote:

Why go anywhere at all when you can see other places on TV, work from home, and get your food delivered?

I'm sold! Where can I sign up, please?

[BillO]

BigEd wrote:

> I honestly do not understand the idea behind this project

That's a good way to put it. The project makes complete sense to me.

Thinly veiled insults will just never stop winning you friends, Ed.

BigEd wrote:

I don't much like it when project threads are peppered with comments asking why the project exists.

Then you should be tickled pink, right? As I did not ask why the project existed.

[BillO]

Rumbledethumps wrote:

If all you can think of are things that can be done with emulation, stick with emulation. Or just write it native.

If you want to learn about and tinker with real hardware, the RP6502 chipset is a strong foundation. You could, for example, drop the Pico VGA and design your own VGA system. Or do experiments with DMA. Or load it up with real SIDs and OPLs for some monster music. The Picocomputer 6502 reference design with its single 6522 is only an example of what's possible. It's a toy computer for 6502 hobbyists. It's fun, affordable, educational, and visceral.

In your car analogy, does the twin turbo cost next to nothing? The Pi Pico is $4 while a W65C02S is $10. And why build a car at all when you can take the bus or a taxi or an airplane? Why go anywhere at all when you can see other places on TV, work from home, and get your food delivered?

I've built dozens of 6502 based systems. However, I tend to take a more traditional approach. I'm not big on emulation at all. Quite the opposite. I just thought that since you had done so much of the project in the Pico you could just take the next step and have a $4 6502.

And again, you (and Ed) seem to be taking my comment as some sort put-down. It's not. Just a comment from my perspective.

[Rumbledethumps]

BillO wrote:

I just thought that since you had done so much of the project in the Pico you could just take the next step and have a $4 6502.

Why me? It's your idea, run with it and submit a pull request. Not everyone needs a 6522 so "picos only" would be a viable configuration for some folks.

[BruceRMcF]

BillO wrote:

... I've built dozens of 6502 based systems.

Yeah, that makes it sound like you aren't one of the core target audiences. It seems likely the appeal of the scaffolding provided by the RP MPU would be stronger to those who aren't very deep into their first dozen 6502 systems.

[Jmstein7]

BigEd wrote:

> I honestly do not understand the idea behind this project

That's a good way to put it. The project makes complete sense to me. But having written on this topic several times before, I don't feel motivated to go through it again - I think it's up to you, to read more and think about what the motivations might be, or to shrug it off as differences in preferences, and move on.

I don't much like it when project threads are peppered with comments asking why the project exists. The answer, of course, is that someone thought it interesting and worthwhile. They don't owe anyone an explanation.

Couldn't agree more, Ed. Obviously, he wants to incorporate real hardware. Emulation is a whole other animal. The point is obviously to make the Pico the parallel bus, via the PIO. I think it's cool.

I've seen his project and, personally, I think it would be even better if the entire address bus was connected to the Pico, if possible. But, that's just a nitpick.

[BigEd]

(I should perhaps try to clarify, that no insult was intended. A person not understanding a thing is not the same as a person saying a thing is nonsense, and that distinction was what I had in mind. "That's a good way to put it" was sincere. A person not understanding a thing is not necessarily anything about intelligence, and I wasn't commenting on intelligence. I was, I suppose, commenting on perspective.)