Do you know what would be perfect? This:
https://www.tindie.com/products/8bitforce/retroshield-6502-for-arduino-mega-2/
For the 65c02. This an example of something I would be interested in making. Minus the chip, because I have my own stash of those



Jonathan

Okay, perhaps I'm missing what your goals of using a 65(C)02 are... in any case, off topic for this specific post, which is usually how new threads get started

In any case, attaching a CPU (6502, et al) to something like an Arduino in the method shown is more like putting the CPU on life support, albeit very slowly. Depending on what your goals are, this could be perfectly acceptable. However, keep in mind that any and all software running at a sub-megahertz speed is going to result in a lot of watching and waiting.

Gordon (drogon on the forum) has implemented both 65C02 and 65C816 SBCs that use an ATmega (IIRC) to front end the processor cold start. load RAM, then release the processor to start and then use the ATmega for console I/O and more. It's an elegant solution... and allows the processor to run at high speeds, ~16MHz.

Bill (plasmo on the forum) has also implemented many different CPUs with CPLDs to manage the process and provide the Glue logic and some I/O. Again, elegant solutions.. and provide for a high speed CPU clock rates, as the intended CPU is "running the show".

I think this topic (yours of course) should get it's own thread... and dive deeper into what you're trying to do with the 6502.

_________________
Regards, KM
https://github.com/floobydust

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x86?  We ain't got no x86.  We don't NEED no stinking x86!

Don't misunderstand - I've already had the experience of building a couple of breadboard computers using 65xx chips, made a little monitor using xmodem to load programs into RAM, etc. I'm just trying to cut down on the wires, and the problems that come with them. And, no, I'm not running a 65c02 with an arduino, either It's the form-factor. I want to be able to have, like, a modular design that doesn't require an afro-full of wires each time I want to make a change. Plus, pmod boards with chip sockets would be great with xilinx boards.

Jon

Okay, so I guess I'm still not grasping exactly what you're trying to do or accomplish with the 6502. You linked the Tindie shield stating it would be perfect, which shows it attached to an Arduino... and my response was specific to what you linked to. So perhaps you didn't fully explain what it is you liked about the shield and how you plan to use it?

I also prefer to avoid extreme prototyping... get enough bits and pieces working, then create the final schematic and make a PCB to implement. It's pretty easy these days, compared to the 70's! Also, I'm not 100% certain on what you reference as a "pmod board". Digilent has their own specification and a large offering of boards for this. It might be useful to provide more detail on what you think you want to make as a CPU pmod board and what you're going to connect it to as well as what you expect it to do and the benefit from it. I'm just suggesting here.... and... might as well start a new thread on this, as this has strayed quite a bit.

_________________
Regards, KM
https://github.com/floobydust

Agreed. What would the proper forum category for the new thread be?

Jon

I'd say soldering is more like using a knife for cooking. It is pretty slow and awkward when starting out and after a while you get faster and make fewer errors. And maybe get a blister or two along the way.

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In theory, there is no difference between theory and practice. In practice, there is. ...Jan van de Snepscheut

How 'bout Hardware.

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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?

Hello All,

Today the PCB's arrived!



They look good!


Best regards,

Edzard

That they do.

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x86?  We ain't got no x86.  We don't NEED no stinking x86!

Yes, the PCBs do look quite nice (in blue). PM me... I'll send you a utility program that you can load to setup the RTC and format the Compact Flash drive so you can use it with DOS/65. Granted, it's not quite at a 1.00 version, but it certainly helps in sorting out the RTC setup and getting the CF Card accessible from DOS/65.

Note: DOS/65 doesn't do anything with the RTC... at least not yet. I'm hoping that Richard Leary will eventually provide support for the RTC, time will tell.

_________________
Regards, KM
https://github.com/floobydust

_________________
x86?  We ain't got no x86.  We don't NEED no stinking x86!

Maxim DS1511Y... sorted out the BIOS and the utility to set it up for date/time... all working quite well now. I opted to set the last two bytes of the NVRAM to "KM" as a signature, showing that the RTC is present. Once BIOS detects it (setup by the utility program), it copies the time/date to the BIOS variables on startup. The BIOS code manages date/time after that, else defaults to EPOCH time if the RTC is not found.

_________________
Regards, KM
https://github.com/floobydust

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x86?  We ain't got no x86.  We don't NEED no stinking x86!

Yes... I have full source code for DOS/65. I started with Richard's most recent version 3 ROM based code. Initially, I kept the CCM and PEM code identical to what he sent. All I changed was the SIM code and wrote a monitor layer to interface to my BIOS. I later rewrote the SIM and included the code to directly interface to my BIOS, which saved some ROM space and also reduced some overhead. I later modified his CCM and PEM modules to take advantage of the CMOS instructions and addressing modes and reduced ROM space even more.

However, there is no code for implementing time/date. The calls are basic RTS functions. I haven't yet looked at doing this, as I would prefer to have Richard's input on how he would want this added in. I do think it would be a nice addition to the code base. The same can be said for using a second UART port for Reader/Punch functions... as the calls are there but just RTS functions. This part I will add in at some point, as my next SBC will use a 28L92 UART.

The current DOS/65 source code (now 3.03) is on my GitHub page.

_________________
Regards, KM
https://github.com/floobydust