From mboxrd@z Thu Jan 1 00:00:00 1970 From: johnh@psych.usyd.edu.au (John Holden) Date: Wed, 11 Oct 2006 08:20:04 +1000 Subject: [pups] thrust meter? In-Reply-To: References: <452424F9.28243.1AB56C7E@brian.quarterbyte.com> <1AC552DD-C287-4001-A5BC-95DD1092ACA8@psych.usyd.edu.au> <452B625A.1070304@softjar.se> Message-ID: <47CD212B-FA24-40F9-85D3-0CF325462CC8@psych.usyd.edu.au> 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