5 Oct
2006
5 Oct
'06
4:17 a.m.
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.
Brian
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5 Oct
5 Oct
12:15 p.m.
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.
I believe so...
(Dave leans over to dig out article.)
OK, page 27 of AUUG Vol 2 No 5 (Jun/Jul 1980).
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).
The credits are:
Designed originally by Pete Madams (Essex), modified by J Feenstra
(Nijmegen), and this drawing executed by Paul Griffith (Essex).
-- Dave
9 Oct
9 Oct
11:02 p.m.
On 05/10/2006, at 10:15 PM, Dave Horsfall wrote:
On Wed, 4 Oct 2006, Brian Knittel wrote:
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
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). 
10 Oct
10 Oct
9:05 a.m.
John Holden wrote:
On 05/10/2006, at 10:15 PM, Dave Horsfall wrote:
I got them here. :-)
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.
Johnny
On Wed, 4 Oct 2006, Brian Knittel wrote:
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? 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).
10:55 a.m.
On Tue, 10 Oct 2006, John Holden wrote:
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).
According to the article, it was indeed for the 11/45.
-- Dave
11 a.m.
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.
Which reminds me; try holding the light-pen of a GT40 against its own
console lights :-)
-- Dave
10:20 p.m.
On 10/10/2006, at 9:00 PM, Dave Horsfall wrote:
On Tue, 10 Oct 2006, Johnny Billquist wrote:
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).
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.
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
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6 comments
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participants (4)
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Brian Knittel -
Dave Horsfall -
John Holden -
Johnny Billquist