From mboxrd@z Thu Jan 1 00:00:00 1970 From: johnh@psych.usyd.edu.au (John Holden) Date: Tue, 10 Oct 2006 09:02:08 +1000 Subject: [pups] thrust meter? In-Reply-To: References: <452424F9.28243.1AB56C7E@brian.quarterbyte.com> Message-ID: <1AC552DD-C287-4001-A5BC-95DD1092ACA8@psych.usyd.edu.au> 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