> There was the 6803/6303 processors which used a superset of the 6800
> instruction.
>
> It included a MUL instruction which multiplied the A and B register
> and left the
> results in the D register (which was the A and B registers combined).
>
That's how the 6809 works too, BTW...
> I believe there were a few other instructions added to deal with the D
> register.
> STAD and LDAD, maybe a shift D? TXD? TDX? I went looking for my old
> 6303
> manual and couldn't find it. :^(
>
In 6809-land those were ldd and std...
-Clay
