So I'm not super clear on how 65816 / 65265 interrupts work... The monitor itself must use them, right? So if I want to call its functions like put_chr or whatever, all I should have to do is cli in my main() before I do anything, and then it'll use the monitor's handler.

And in fact that seems to ...

It disables interrupts? That's stupid.

Okay, honestly, a non-interrupt-based version is better for me anyway because I'm going to be writing something that will run without the monitor (and its interrupt handler).

whartung: been asking myself that for days....

All I can figure is that it's related to IRQHandler. That's the symbol, along with main(), that c0.obj (WDC's init code) references that I have to supply. I'd love to have the sample C project that WDC claims comes with their tools...

That's really what I was hoping, but I couldn't find any examples of anyone having written those routines for the 265, or figure it out myself.

That was you? I've been relying heavily on that guide, I was going to submit a PR to it detailing, basically, how to make printf() work. Only I kept not being able to make it work.

I haven't used the 816 at all (or anything 6502 but this in fact, I've messed with Z80s and AVR microcontrollers but ...

Oh man, thank you so much, that's the first piece of example C code for this thing I've seen, and it worked!

I had to modify it a little bit, their compiler still doesn't link anything without me defining an IRQHandler function, but since that code doesn't use the IRQ handler (which I guess the ...

I'm sorry, I don't know enough yet to understand what that code is doing. What are UIFR, UART, and ARTD0?

I don't have anything for a handshake, my entire code is above. I'm trying to use the USB serial thing hooked to the monitor ROM.

So if that interrupt handler is supposed to empty it, maybe the problem is that I'm implementing IRQHandler with an empty function. But I can't find anywhere what's ...

And I spoke too soon. I replaced my monitor_putchar code with this: void monitor_putchar(char ch) {
asm {
lda %%ch
send_loop: jsl $00:e063
bcs send_loop
}
}
And now I have the exact same problem I had when using put_chr: try to output more than 9, and it outputs nothing. Output 9 or fewer, and ...

whartung: Sorry, I didn't explain this well. In your example I wouldn't see anything, no As or B. If you remove the B then I'd see nine As. And yes, the monitor can print as many characters as it wants. In fact if I make a program that prints nine characters I can run it over and over again without ...

I finally figured out how to get the C compiler working but I've hit another weird problem. I have the following code: void monitor_putchar(char ch);

void main() {
const char *str = "\nHello there\n";
int n;

for(n = 0; n < 5; n++)
monitor_putchar(str[n]);
}

void monitor_putchar(char ch ...

Which is exactly what I'm doing now, but it would be nice if they told you that, maybe along with a #define you can do to enable monitor-outputting versions.

The memory model thing is probably why you have to manually tell it what to link against. There are five copies of the std lib, one for each memory model and (I guess?) one for the 6502.

And it makes sense that fcntl.h would have no implementation, it would just be nice if the manual would TELL you ...

I think I might have figured this out, no thanks to the manual: wdclib -s shows me that all the C library functions are in the whatever.lib files, and if I add those to the linker then it finds them and complains that some other things are missing: __unlink, __close, __isatty, __write, __lseek. But ...

Although to be fair it does compile and link things that don't use the standard library. As long as I'm willing to reimplement all that stuff myself (or find an open source one) I can use it.