On 23 January 2016 at 19:18, Greg Harris <g...@harrisconsultinggroup.com> wrote:
> Warning tangent alert... > > Back in the day (early 80's) one of my mates to test the boot process of a > new machine, would set his transistor radio going next to the machine. > It would be totally off station so as just to hear static. > Then as the machine boots, you listen to the RF interference. > As the machine executes different parts of the boot sequence there were > clear changes in the tone. > (memory checks are long sequence of the same tone, other processes are all > over the place, nothing is nothing) > You need to know the sound of a healthy boot to recognise an unhealthy > boot. > > I thought he was mad until I saw it! > I do not think it would be as valid today with much faster clock speeds. > This was on machines based on M6800 CPUs ( > https://en.wikipedia.org/wiki/Motorola_6800). > This sounds similar to an unusual feature of the GHC Haskell runtime. From the user manual: *4.17.7 RTS options for hackers, debuggers, and over-interested souls* > These RTS options might be used (a) to avoid a GHC bug, (b) to see “what’s > really happening”, or (c) because you feel like it. > Not recommended for everyday use! -B Sound the bell at the start of each (major) garbage collection. > Oddly enough, people really do use this option! Our pal in Durham > (England), Paul Callaghan, writes: “Some people > here use it for a variety of purposes—honestly!—e.g., confirmation that > the code/machine is doing something, infinite loop > detection, gauging cost of recently added code. Certain people can even > tell what stage [the program] is in by the beep > pattern. But the major use is for annoying others in the same office. . . ” -- Thomas Koster
