(Lots of reasons for that last question, but probably off-topic here... suffice it to say, perhaps, that every one of us has a variety of preferences which may shift from project to project, and any expression that something is out of scope is always a personal statement.)

And here is my USB driver code for it that lets the Commodore PET use a USB keyboard and mouse https://github.com/fachat/usb65
It's using the VIA shift register for SPI out, and an external serial to parallel SR to present the received byte to a VIA IO port.

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Author of the GeckOS multitasking operating system, the usb65 stack, designer of the Micro-PET and many more 6502 content: http://6502.org/users/andre/

Thanks for that, fachat - the more I look into USB the more complicated it looks!

Neil

The reason why USB is so complicated is because it's versatility.

You can dynamically plug in any type of devices, and the drivers have to cope with that. And then you can dynamically unplug devices, which opens a whole new can of problems.

If you have a static setup, it might be going in a simpler way.

André

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Author of the GeckOS multitasking operating system, the usb65 stack, designer of the Micro-PET and many more 6502 content: http://6502.org/users/andre/

Indeed, André. Something that needs only look for a keyboard (low speed) shouldn't be too difficult, but if you want it to see a wireless dongle not only is it working at the next speed up but it probably needs to talk through a hub - for a mouse/kb combo, for example. That's probably looking at a separate processor to handle things.

Neil

That is the reason my USB stack has 8k or so. It does handle a USB Hub. Unfortunately only for the sh811 (IIRC) USB chip. Not the Max3421. Yet.

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Author of the GeckOS multitasking operating system, the usb65 stack, designer of the Micro-PET and many more 6502 content: http://6502.org/users/andre/

ironically, a lot of modern higher quality USB Keyboards actually pretend to be multiple keyboards plugged into a hub to get around the limitation of how many keys can be pressed at once. the feature is called "n-key rollover".
I think (but i'm not 100% sure) USB Mice do the same to get higher DPI settings to work.
also IIRC non-Bluetooth wireless keyboards/mice just transmit the raw USB packets via radio with no additional controllers or translation inbetween, so they will behave exactly like wired keryboard/mice and therefore don't need any extra code to handle.

and from what i've read online (EE StackExchange) USB hubs seem way simpler than I expected, though i can't tell if that translates into "being simple to handle in code" as well. as you likely have to keep track of what device you're currently talking to, which ones are currently plugged in, etc.