In fact C teaches a model of a semi-standard virtual architecture - loosely based on the DEC PDP7 and/or PDP11 - which is long gone from real hardware.

Real hardware today has multiple abstraction layers under the assembly code, and all but the top layer is inaccessible.

So there's no single definitive model of "How computers work."

They work at whatever level of abstraction you need them to work. You should definitely be familiar with a good selection of levels - and unless you're doing chip design, they're all equally real.

    char *dupstr(const char *src) {
       char new[1024];
       strlcpy(new, src, 1024);
       return new;
    }