From: utzoo!decvax!goutal Newsgroups: net.followup Title: Re: RFI & Terminals Article-I.D.: decvax.369 Posted: Mon Jan 3 23:29:39 1983 Received: Tue Jan 4 03:50:48 1983 References: ihuxx.223 Catching up on 'old news'... Note that there used to be a program for the PDP-12 (and -8, too) that would produce AM music you could listen to on a nearby AM radio. I'm sure other machines had such programs. (Yes, this is getting far afield from RFI and *terminals*). Today, I believe, the FCC frowns on this sort of thing. Sigh. The -12 also had a speaker (!) connected to the link (carry) bit, for some reason or other, and it turned out mighty handy for the same reason as the fellow mentioned about his HP-45 -- tracking the progress of one's program (of course, there were front panels in those days, too, that told you a lot). Moving back into the realm of possibly dangerous, or at least noxious, radiation... Does anyone remember working with the old Data General machines (circa 1973... maybe even still!)? For those of you who don't, I remember being able to tell what stage of compiling or linking my program had gotten to, simply from the whine of the power supply. And I don't mean that ours was in bad repair; it was the normal behaviour of the 8xx and 12xx Nova series, due, I believe, to the use of switching- type power supplies (I may have this a bit adrift... it's been a while since I understood much about hardware) -- the effect was similar to the flyback whine in some (especially older) TV's. Note that this was not just *faint*, either! I could do that trick of telling what it was doing from several offices down the hall! Anyhow, it used to give me a headache, and I took to wearing airport- type silencing muffs. Amazing the lengths some companies will go to to compete! -- Kenn (decvax!)goutal