[pups] thrust meter?

[John Holden]

On 05/10/2006, at 10:15 PM, Dave Horsfall wrote:

> On Wed, 4 Oct 2006, Brian Knittel wrote:
>
>> The thrust meter project -- was that an analog meter that displayed %
>> CPU utilization? I remember that Tom Ferrin had one mounted in the
>> middle of a DEC panel filler on the 11/70 at the Computer Graphics  
>> Lab
>> at UCSF. It was really delightful having this analog meter  
>> bouncing up
>> and down as people worked away.
>
> It integrated the BUS BUSY signal over a suitable time constant  
> (and my
> electronics knowledge is a bit too rusty to figure out Tc, but with a
> 10uF tantalum capacitor I imagine it would be a few seconds).

Um, depends what you mean by thrust. It was originally designed for a  
11/45
where bus activity would have been a fare indication of machine load  
since
all memory and i/o used the unibus (I'm excluding the effects of fastbus
memory on 11/50 and 55's).

The 11/70 unibus was actually slower than the 11/45, and generally  
didn't
have memory or disk/tape i/o on it (separate memory bus and massbus). So
'thrust' was probably mainly character i/o (dh and dz's) and older
disk/tapes (RK05's etc)

Now, where's 11/70 maintenance printset?

Cheers
John