[pups] thrust meter?

[johnh@psych.usyd.edu.au (John Holden)]

On 10/10/2006, at 9:00 PM, Dave Horsfall wrote:

> On Tue, 10 Oct 2006, Johnny Billquist wrote:
>
>> Hmm, but yeah. Since the bus might be idle even though the CPU is
>> running, you might not get a very good reading by looking at the  
>> unibus.
>> But I think there are other signals that would be better to integrate
>> over. Such as the MASTER lamp (or is it the CPU lamp perhaps?) of the
>> front panel.
>

The MASTER lamp signifies that the CPU has the unibus, hence a  
similar problem
to using BUS BUSY. You could use KERNEL/SUPERVISOR/USER signals as an  
indication
of context switches. My favourite is a light chaser using the data  
display from
the idle loop. Only works on an 11/45/50/55/60/70 (a bit boring on a  
11/60 as
it had a 7 segment display).

> Which reminds me; try holding the light-pen of a GT40 against its own
> console lights :-)
>

Got one in my office. The lightpen latches the current x/y  
coordinates from
the d/a converters. Aim it at something that will trigger it and you  
get random
hits all over the screen