> On Sun, 9 Jun 1996 11:39:41 -0600 
>  benh@inlink.com (Ben Hockenhull) wrote:
> 
>  > I have heard that the 030@50mhz chips are internally clockdoubled.  I am
>  > wondering if this is indeed true.  If so, I would think that I'd see an
>  > increase in processing speed, but not in external I/O.
> 
> On the hp375, which was basically an hp380 with an L-shaped daughterboard 
> holding a 68030@50 and a 68882 (plugged into the 040 socket), I believe 
> there was a 100MHz crystal installed.

It must be "externally clock-halved", then ;-) I remember many of the
Motorola M68K CPUs trigger/sample its output/input signals at both
falling and rising edges of the clock input, so it was kind of a
common practice to clock the CPU-bus interface circuitry at twice the
CPU clock frequency.

> So, I'm not sure where the "internally clock-doubled" notion comes from :-)

Probably he was confusing the 040 rumored to be internally
clock-doubled (which is only partially true) and the 030.

ken