Catch up on stories from the past week (and beyond) at the Slashdot story archive


Forgot your password?
Check out the new SourceForge HTML5 internet speed test! No Flash necessary and runs on all devices. ×

Comment Re:GPS clock (Score 1) 291

The cool thing about CDMA is that it won't work without precision time standards in each of the base stations - i.e., GPS receivers with antennas fed through known lengths of feedline (or, alternatively, GPS receivers with known lengths of wire providing a 1 pulse per second reference). Net result is that CDMA can give sub-ppb time reference, and it works great indoors, too. Probably overkill for getting the kids up in the morning. :-)

Comment Re:How about the FCC just does its job? (Score 0) 173

The FCC has, over the last couple of decades, gone a long way toward outsourcing radio regulation. Now, they're predominantly a finance agency conducting spectrum auctions and counting on competitors to police each other. Often, this actually works. Sometimes it doesn't. To be sure, they do have some field-based, rapidly-responding capability to identify interference, especially for (and between!) public safety users, and they occasionally use this to levy big fines to scare everyone else into compliance - I wouldn't want to absorb the typically $11K fine, personally. But their enforcement division is nothing like it used to be.

As far as what used to be called "type approval" (the pre-marketing certification that a device is compliant), it is now 100% outsourced. The fees for this run between $100K and $500K, depending on the complexity of the device and the section of the FCC regs you have to be compliant with (47CFR). 47CFR95 devices are cheap, 47CFR90 devices aren't. 47CFR5 devices can (usually) be self-certified, but they can't be sold.

So, unless Open Source drivers can be sold and operated under Part 5, and it's totally not evident to me that they can, then certification cost is going to mean that someone if going to have to pick a tiny handful of reference devices, certify some binary blobs, and call it done. My guess is that those someones would be Red Hat and quite possibly Lenovo - the one and only marketable Linux Laptop would perhaps be enough of a niche to pursue. In principle, someone like, say, Intel could certify a blob for a mezzanine card and sell the card to vendors, but bear in mind this means the antenna must be fixed onto the card and certified as a package.

Sorry to be such a downer...

Comment Re:Don't Panic! (Score 1) 68

If you're reading this article, you may also be interested in the E. H. Danner Museum of Telephony located on the grounds of Fort Concho National Historic Landmark in San Angelo, TX. While there, you might as well see the Robert Wood Johnson Museum of Frontier Medicine, also on the grounds. Don't go on a full stomach. And that's about all there is to do in San Angelo.

Comment Re:HYPE (Score 1) 35

Still, you could have a lot of fun with someone... this is the sort of thing that happens when you google "dental robot vomit":

"The 600 series had rubber skin. We spotted them easy, but these are new. They look human... sweat, bad breath, everything. Very hard to spot." -Kyle Reese

Comment Re:No it hasn't (Score 2) 157

I'm starting to suspect we're in violent agreement here. :-)

I've physically, with my eyeballs, seen Linux running on some sort of z series a couple years ago. I saw AIX/370 running on some sort of box around 1990-92-ish, so I know it can be done (parenthetically, I was told it shared no code at all with AIX/6000). My entire point with virtualization is not to suggest there's a problem with the mainframe. Whether it makes sense to or not is completely beside the point.

Comment Re:No it hasn't (Score 2, Informative) 157

Z series and power definitely do not share an instruction set, and they have really substantial differences, but that isn't keeping the engineering teams all that separated, if indeed they are at all.

Quoting Timothy Prickett Morgan from , "And as has been the case in the past, the Power and z processors are designed by a single processing team and are borrowing technologies from each other. This does not, however, mean that IBM is creating a converged processor that can support either Power or z instruction sets." My hazy memory makes me think they're sharing FPU blocks, possibly one of the bus interfaces, and it seems like one of the cache blocks (L3?). Z has plenty of custom hardware - I think it's fair to say it's predominantly custom - the branch predictor would have to be pretty different, and of course power doesn't have a BCD arithmetic unit.

Point being, if you're going down the Z Series road to run a Unix-like OS, why not just (conceptually) stop early, end up with something like Power, and call it good? Anyway, I'll argue that they're spiritually and economically related, and there's more than a passing family resemblance. Kind of like power and modern ("advanced server") iSeries, though that's getting more into Deliverance territory.

Meanwhile, channel controllers aren't as dumb as they look. A little wikipedia action here (I know, citing wikipedia, but it's monday and I'm still tired): . Turns out the little dickens can do a decent amount of work on its own. I think the wikipedia entry is showing its age... seems like IBM's done a lot more work since this.

I remember when SASI came out. I looked at the spec and thought "Hey, this is a lot like a channel controller." Then I read some more and decided "No, a channel controller is much smarter. But this isn't bad." SASI became SCSI and everything else flowed downhill from that. At a very real level, Linux is forcing a million dollar fibre channel array to look more or less like an ST506 connected a board from 1984. Wild.

Slashdot Top Deals

When I left you, I was but the pupil. Now, I am the master. - Darth Vader