On Sat, 20 Sep 2008, Gene Buckle wrote: Now as soon as I can figure out how to do POTS modem dialing through a cell phone, I'll call. -- David Griffith dgriffi at cs.csubak.edu A: Because it fouls the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail?

It's my understanding that Verizon cuts your POTS copper and THAT is why you can't use a modem. :) They may also be "compressing" the analog signal on whatever device they give you to allow you to continue to use your old POTS gear. g. -- Proud owner of F-15C 80-0007 http://www.f15sim.com - The only one of its kind.

Jim Leonard wrote: Umm Upload rate is what ... BBS's send not suck data. ;)

On Sun, 21 Sep 2008 19:43:38 -0500, Chris Elmquist wrote: For those with home businesses, be warned the TRANZ credit card machines are not happy with VOIP and want to be connected to a POTS line. Both my CC machine and my DirecTV boxes are connected to the analog side of my POTS/DSL line. They both autodial 1-800 numbers so the basic metered local only service works just fine. I use my cell phone or the "Business" ISDN line for all voice and fax calls. The other Bob

And presumably once you get a new surround-sound system you'll never want to listen to a vlaved radio again. Once you get a modern Pentium (or whatever) PC, you'll never want to use an 8 bit micro, or a PDP11, or... again. -tony

On 22 Sep 2008 at 15:27, bfranchuk at jetnet.ab.ca wrote: Well, to be fair, as in vintage computers, there's a "time effect". I remember the first time that I heard FM (monophonic) broadcast radio--I was blown away by the fidelity. I probably wouldn't think much of the same sound now, but emotions can stay with you a very long time. Similarly, I think the speed of a CDC 7600 mainframe would seem glacial to me now. Memory is a funny thing. Cheers, Chuck

I have a VoIP phone line with my cable television provider, and I can use a modem. (The one or two times a year that my cablemodem service goes down, my phone service is usually still up and I can use dial-up, and have indeed done so). Jim

On Sun, 21 Sep 2008, Gordon JC Pearce wrote: Someone used to market a gizmo that when plugged into a regular cell phone would present a seemingly genuine POTS line. That's partially what I'm after. The other solution could be to use a Port-O-Rotary and an accoustic coupler. I plan to do this anyhow with my PT-210 terminal when I can justify spending the money for the phone. -- David Griffith dgriffi at cs.csubak.edu A: Because it fouls the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail?

The system is configured for 300 baud, 8 bits, 1 stop and no parity. g. -- Proud owner of F-15C 80-0007 http://www.f15sim.com - The only one of its kind.

Joachim Thiemann wrote: Used to be that when I received a 'dead phone call' (phone rings, but no response to a 'hello'), I'd whistle into the phone, varying the frequency of my whistle, and sure enough, sometimes I'd get a modem responding. Somebody with the wrong number in their modem or fax machine..

You can do it if you have an analog phone (and still have analog service where you live), but it doesn't work on digital mobile phone networks, alas, unless your provider still offers circuit-switched data (where it actually dials out with a real modem on your behalf, and forwards the data over the cellular network). Jim

Don't keep me in suspense, what was the problem? -tony

Right... When I was working on the Z90, I found it helpful to rememebr that it was a Z19 with the processor board added (making n H88) and then the floppy disk system added after that. And that it was best to remove things in the reverse order. Take the floppy drive out first, then the add-on boards, then the CPU board and finally the Z19 board, etc. I assume you were doing this with the machine turned off. In whcih case what's the problem with the yoke? It's not a colour CRT so there's no real alignment problem if you do slightly move it. There's no stored high voltage on the yoke. -tony

(Maybe I already told this history here, but here it is again) I never studied electronics. But when I worked some 4 or 5 Km from my house, I used to go back home walking and looking at different people on the streets at night. Near my work there was a very small electronics' school, and I wanted to take a look. Always passed by it and never had the courage to climb the stairs up. Someday I enrolled on that "basic radio & TV course" :o) The classes were boring. I didn't told the teacher I had prior experience with electronics (actually I was - at that time - working repairing and modifying MSX, Amiga and Sinclair computers). But one class was very interesting - how to deal with high voltage :o) The teacher assembled a rigged-up flyback transformer, with a pair of 2N3055 or like, and created something-shockingly that would give around 6000 volts of electrical shock. And told that no one would leave the room before taking a shock from the machine! :oD Imagine what a fuzz! :oD One by one, seeing the teacher and other students taking shocks and telling "it don't hurt!" tried and saw - there was NO pain! :oD A small itching on the finger, but no real pain involved. Ok, let's be serious here: Most of the shock you take from CRTs is more "oops" than electrical shock. A 26000 volts shock hurts, but not THAT bad. There isn't enough power to make your heart stop. If the monitor is turned on, the frequency is so high that the electrons travel on the top of your skin. If the monitor is off, there is NO enough charge on the tube, and it is discharged by a some megohms resitor to ground. Period. So it is not a life concern, but only the scare. Don't be scare of CRTs, they bite but don't hurt :o) Alexandre PS: I'm not a medical doctor, I don't warrant you of nothing I said here. If you put your tongue on the wrong flyback end and it hurts, I'm not responsible. Void where prohibited. Your milegage may vary. Batteries not incluided. If you die because anything I wrote here, the problem is enteirely yours.

Not true. CRT accelerator voltage is DC. It's generated from the deflection voltage which is certainly AC (though not all that high a frequency -- dozens of kHz perhaps, which might give just a little skin effect but not a lot), but that's all gone by the time it goes into that wire attached to the CRT. The low current capacity of that supply is what helps. (Of course that assumes the surprise from the jolt doesn't cause you to jump back and trip and break something...) The right answer is "don't fool with it, make sure it's discharged. paul

On 22 Sep 2008 at 11:26, der Mouse wrote: Yeah, but it's been a *loooong* time since I worked on electronics gear with my feet. My aging eyesight just won't let me maneuver those little parts with my toes... :) Cheers, Chuck

der Mouse wrote: If I am that close ... I'll get shocked where I piss my pants on the first KA-BOOM!

That's pretty close to what I saw. The sketch of the argument: Draw a graph with shock intensity on the Y axis and shock timing, as a proportion of the way through the normal heartbeat period, on the X axis. Consider a path that includes the X axis, vertical lines just inside the edges of the graph, and a line joining the last two at some high level of shock. For each point on the graph, consider the phase shift between the original heartbeat and the heartbeat after the shock. At zero intensity, of course, nothing happens. If the shock is correctly sychronized, the phase is unchanged. And a strong shock will restart the heartbeat in sync with the shock (this is basically what defibrillators do). This means we have a closed path, and a variable which can be expressed as an angle, such that the variable makes a full circuit of the possible angles as we walk around the path. Bringing in topology, this means there exists at least one point inside the path at which the variable's value is discontinuous or undefined. Physically, the most reasonable interpretation is that there is a (probably small) area on the intensity-vs-timing graph inside which the heart goes into fibrillation rather than resuming a regular beat. Of course, there are many respects in which the mathematics might not match reality; perhaps most notably, I'm not convinced the assumptions involved in modeling the new heartbeat phase as a continuous function are valid. But I certainly find it a thought-provoking argument. /~\ The ASCII der Mouse \ / Ribbon Campaign X Against HTML mouse at rodents-montreal.org / \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B

On 22 Sep 2008 at 19:07, Rik Bos wrote: As I understand it, at lethal currents, the path of the current is just as important as the magnitude of the current. Any significant current passing through the trunk of the body is bad news. That's why the old electrician's advice of wearing shoes with rubber soles and keeping one hand in a back pocket when working on circuits known to present a hazard is just plain common sense. Be careful out there. Cheers, Chuck

Gene Buckle wrote: I squatted down to get a line-of-sight on some jig clamps once, and reted my butt on the welding rod I had just dropped on the floor. 220V AC welder, set at about 90A, and I was standing in a puddle of water and resting wet gloves on the grounded jig table. It was NOT an experience I'd like to repeat. That table weighed about 400 pounds, and my work mates said I lifted the end off the floor. The obvious injury was fairly painful, but pulling every muscle from my ears down was much, much worse. I didn't walk, stand, or even sit right for weeks. Doc

On Monday 22 September 2008 16:03, Tony Duell wrote: Basically it comes down to "don't whack the neck of the tube". I had one situation where a guy was bringing me a TV to look at and he'd taken the back off of it to get it in the trunk of his car, for some reason. We got it up the stairs just fine, and through the little foyer just fine, but when it came to getting it into the room I was using for an office at the time, we had bad luck. He wasn't looking at the back of the set and cut the tube right off, against the door frame. I told him I'd test the rest of it out and let him know if it was worth fixing, which as it turned out it wasn't, two-thirds of the small tubes in the set being bad... I remember really old sets that had to have a small HV "filter" capacitor because they didn't have that coating. In real early color stuff there was a separate focus rectifier, but the focus voltage is typically 20% of the HV, so a divider came to make a whole lot more sense later on. In some sets they were a separate little component (Zenith stuff I worked on in the early 1970s comes to mind and in fact I just scrapped one of those not too long ago) but anything more recent and it's built into the flyback transformer. One experience I had with that stuff was in a customer's apartment, where I was testing tubes, and I had at that point taken to ignoring all those little paper stickers they plastered all over the inside of the set figuring that I'd already seen them all. Only I hadn't seen the one in that particular model of set that said that you should tilt the HV box out before trying to reach behind it, and I reached behind it without doing so. Which put me in contact with the base of the HV rectifier tube, and the wire coming out of it to the 2nd anode. My wrist impacted the metal edge of the cabinet twice on the way out, creating nice deep gouges, and I bounced around the room for a bit until things calmed down... I have one too, brand name is Polaris. Only I don't think it's a 50uA meter, as there are also a couple of terminals on the sides of the meter portion of it to allow for it to be used to measure cathode current, a common requirement on those old tube sets, keeping that current down. Not a problem if you have that 2nd anode wire disconnected from the tube, and you short it to ground with a wire. However! The glass and coating capacitor of the tube makes a wonderful demonstration of what they call "dielectric absorption", which I found out the hard way with my "test jig" -- basically a dud tube (weak green) that I picked up for under $10 back when, and which had a yoke on it and a bunch of adapters I rigged up as needed. I'd short that to ground to discharge it as needed, and then a while later it'd give me a little bite, to let me know that it still had some charge in there... I know exactly the sentiment you're expressing here. :-) That approach was taken with some very early TVs as well, but the flyback transformer approach was much cheaper to produce. The key point though, is the path that current takes. If it just hits your arm that's one thing, if it goes through your heart then you are likely to have serious problems. One old mono monitor that I just scrapped out (bad screen burn among other things or I wouldn't have) had eight little magnets attached to the outer edges of the yoke. Glued on, but if you knock one of those loose the display could end up being a little distorted... No, that's static convergence and color purity. Typical early TVs had an adjustment to move the yoke toward the screen and away (for purity) and an assembly with three magnets for static convergence, plus a "blue lateral magnet". That set things up for the center of the screen, and then dynamic convergence adjustments on a small board (that could typically be repositioned to be accessible from the front of the set) dealt with the edges. This was 12 - 16 different adjustments, all of which interacted with each other to some extent. Yup, getting _those_ shocks was no fun at all when I was first learning this stuff, as a kid. :-) -- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, a critter that can be killed but can't be tamed. --Robert A. Heinlein, "The Puppet Masters" - Information is more dangerous than cannon to a society ruled by lies. --James M Dakin

On Tuesday 23 September 2008 15:50, Tony Duell wrote: I remember those but it's been a *really* long time since I've seen one... Ok. I was of the impression that most of the current crop of stuff used those multipliers. Not likely, no. :-) Yes. I tend to rely on those grounds that are attached to the outside of the tube for stuff like that. Unless we're talking *really* old stuff with a metal chassis, OTOH... :-) Making a loud noise in the process to let you know it wasn't pleased with what you'd done. Yes. You'll not get any argument from me on that. Right. That was a part of the process. The other part of it was the forward-rear adjustment of the yoke. BTDT... :-) Yup. Sometimes the convergence yoke was a separate assembly, sometimes it was a combined assembly with the deflection yoke. Supposedly, yeah. Excepting one Trinitron TV that I brought with me when leaving NYC (in early 1978, and it's still working fine although a little dim), most of what I worked on was earlier stuff, delta-gun arrangement. The inline-gun stuff didn't start to take off really until after I got out of the business. I do know that they sure took a whole lot less fiddling with than the earlier stuff did. Which is as it should be. :-) -- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, a critter that can be killed but can't be tamed. --Robert A. Heinlein, "The Puppet Masters" - Information is more dangerous than cannon to a society ruled by lies. --James M Dakin

On Tue, 23 Sep 2008, Tony Duell wrote: And what about a DY802 in a Telefunken SIG100 computer graphics terminal? But admittedly it dates from the early 70s. And there's no PD500 of course. Christian

Just a word: WOW! ;oO Alexandre http://www.tabajara-labs.com.br "raw data for raw nerves" :o)