Subject: Re: PC164 MLB Xtal (Was:PC164 memory bus speeed:-)
To: Jan-Hinrich Fessel <>
From: Nathan J. Williams <nathanw@MIT.EDU>
List: port-alpha
Date: 11/03/1999 16:14:52
Jan-Hinrich Fessel <> writes:

> I just wanted to know what Crystal to put on the PC164 MLB whit a 500MHz CPU 
> and what combination of IRQ-Jumpers is the correct one.
> My board just came in with a set of Crystals (up to 50.00, 36.6 std. 
> installed) and IRQ2 jumpered.

You want the 50.00 MHz crystal; there's a 10x PLL in there somewhere. 

Pick up the pc164 technical manual from
and have a look at page 29 (or 2-5 in atrocious DEC style); it shows
the jumper settings for different frequencies. 500MHz is all four of
the "IRQ" jumpers out.

        - Nathan