broken pin on motherboard

install i/o card with floppy controler,
and disable original in bios.
(you should find it in older computer or
buy it at local computer store)..

A lot of people laugh if you tell them that you went to soldering school, but I'll tell you what.....the training is well worth it.

If you want to get good quality training contact your nearest Air Force Bases Flight Training Detachment and ask if you can sit in on a High Reliability Soldering class, or if the intructor will give you some lessons. After attending one of their training classes, I can approach soldering with full confidence. It's a tough course, and beleive it or not, you may not pass it the first time through, I don't care how good you think you are.....

in soldering or anything, but seriously, to me it's all in the art of the flow. If you can make beautiful flowing old 18g wire connections, header pins aren't that much smaller. I've replaced a few surface mounts and that's tricky, but possible. Youhave to be careful on new boards, and although I used to solder in traces, I use a conductive ink pen now mostly.
Get an iron with a nice tight point and controllable or at least low heat. Get some old motherboards etc. that are dead and practice awhile. Use small diameter solder. If you soldered before you can do this. I use a magnifying glass and small vice as well as various alligator clips to hold stuff. Heat sinks are sometimes needed too, but the best is small diameter solder and just enough heat to make it flow beautifully and no more. I don't really know if that helps, generalist, but really, get some dead parts and practice a short while. It's fun and floppy headers really are not difficult. :)

Yeah, if you don't need a lot of industrial motors, DC does still rock :) Come wire my home music recording studio with DC someday when you get a chance -I could use some clean power there, something Idaho power is not known for *hehehehe*
I still have a subscription to Mother Earth news too, although it's not nearly as wild a publication as it was back in the 70's. Still, we live in glory days for home power experimentation. I'm planning out an entirely off the grid cabin with out back rightnow. Trying to get a solar and wood-fired fake hot-spring near it at present so I'm looking for a Gunite expert with experince in making it look natural :)

Actually, several months ago when the California power fiasco was very much in the news I asked myself an odd question.

The question concerned the power supply in a PC. While it serves a useful purpose, it is a major source of heat and it does waste a lot of power dropping things down to the 12 and less volt DC needed for PCs.

Given that, I asked myself why you don't see external power supplies that provide multiple voltage DC for multiple computers?

The only answer I can come up withis the convenience factor.

Oddly enough, in a very recent issue of Wired magazine, there was a mention of small scale power companies that provide high quality DC power for server farms and such. I guess I was a few months ahead of the curve.

and I thought the highest hack value for diodes was to make your music pre-amp feedback loops sound better.....

I did a similar thing with a variable voltage control off some old military equipment I acquired as a kid :)

Actually Generalist, that's a great idea. An external power supply would potentially greatly reduce the noise inside the box for recording, mP3, AV setups etc.
I used to have a friend that had a home stereo that was all DC with an external power converter. Man, did it sound clean! Unbelievable. You've got me thinking about converting my AV PC now :)

A long time ago, I had a power supply that produced +12, -12, +5, and -5 at some ungodly current level, like 50 amps per wire.

WRT the distributed power, there are a couple of things. Power supplies used to use line frequency step-down transformers. Then about 20 years ago, switching power supplies became more common. The amount of iron you need in a reactive circuit is inversely related to the line frequency, which is why European vacuum cleaners are so huge. Raising the switching frequency reduces the amount of iron.

However, there are technical problems with making a switching power supply produce as much current as a big iron transformer. The current drawn with one PC is fine, but when you get into several, it's usually morepractical to use big iron supplies, and that means weight.

I can remember lugging around a Kaypro "portable" computer, which had a line transformer, and it was not an awful lot of fun.

I remember the 'luggables' and how awkward they were. But back to the topic.

What I would be interested in would be a central DC power supply for any number of low voltage devices in the house. It seems brain dead to have all those devices using their transformers to convert wall power into forms of DC.

Now I will admit that I'd have to rewire portions of the house to handle this, but I may be doing that for a home network anyway. Unfortunately I know enough about electrical systems and electronics to know that I have large gaps in my knowledge. Before I consider making an infrastructure committment, I'd like to know the possible pitfalls.

The info on the weight factor is one example. So is the info on the multi-voltage 50 amp supply. I'm thinking that the weight doesn't matter too much if you're planning on a stationary system. And if you are using direct DC sources like solar cell charged batteries or fuel cells, the system is cleaner.

Ultimately, I'd love to havean in-house system that would allow me to run a lot of devices off low voltage DC while the heavy hardware uses AC. It would be kind of nice to be the only house in a power dark block running a sound system and PCs without having a loud generator in the background.

(Hmmmm. Remind me to get some low voltage monitors...)

Generalist, ever thought of starting a new discussion? hehehehe

But really, the whole house concept is very cool and cuts down on a concern of mine -RMF throughout the house. What about a transformer in the little room where your breakers and main feed are etc. AC to the kitchen and where needed and bedrooms with all DC instead of sleeping next to the AC lines? It just seems like it would be so peaceful and quiet. I honestly think I can feel large current areas. When I go to my friends remote cabin, I get a sense of life without AC lines all over, and there is a difference. I am willing to admit it could be completely psychological, but it might be interesting to live this way.
Maybe Epepke knows this one though, what method would youuse to figure out how much more it would cost you to convert AC to DC before you used it? Of course, your numerous wall warts would already have some loss. Would it be cheaper or more expensive?
I like DC lighting a lot too, my kid can't unscrew the bulb and hurt himself, although I remember the first time I took apart my moms toaster....

P.S. agreed on the old suitcases, man those were heavy and cumbursome, but boy, did they have major status in their day :)

I do projects like that on the cheap, usually using bits from dumpsters.

I do know that you'd need some big fat wire. For the same power and the same loss, the cross-sectional area of the wire that you need is inversely proportional to the square of the ratio of the voltages. In other words, the ratio of diameters is proportional to the ratio of voltages. I don't remember exactly how wide 14-gague wire is, but it's probably close to a tenth of an inch. If you're going for 5 volts insteadof 120 volts for the same power, that means wire that's almost 2.5 inches in cross section. Even if I'm off by a factor of 2 in my memory, this is obviously silly for wire. You'd probably want only to use this on low-power systems, but the voltagedrop could be a problem no matter how little the current. Plus, line devices are designed to be tolerant of voltage fluctuations, but the 7400 series, for example, is only rated from 4.75 to 5.25 volts (unless you get mil spec, and the LS series might be more tolerant than I remember straight 7400).

Of course, you could say "hang the loss" and distribute, say, 7 volts and use a series regulator at the distribution points to cut it down to 5. But still, you'd be using a fair amount of powerto heat the house.