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


Forgot your password?

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.

Comment Re:No it hasn't (Score 3, Interesting) 157

Yup - first thought that ran through my mind: "Oh, they're selling Z Series with crippled Firmware."

I'm kind of stumped. Linux on a Mainframe is a neat party trick, but it doesn't really make a lot of sense. Modern Z Series hardware is heavily derived from Power. Why not just run Power Linux? Mainframe I/O design is intentionally about as un-PDP-like as possible, so it's a bad match for Unix, Linux, or even Windows for that matter (NT ran on MIPS, so it theoretically could be ported to S/390). Mainframes get their performance by pushing computation into the channel controllers, and while you could do something like that in Linux, are any of your applications ready to treat your database like a device driver? Because that's what you'll have to do. And, incidentally, it's why every attempt from AIX/370 to Linux on Z Series has required virtualization and a ton of independent kernels to get anything resembling decent performance. And that's where Dell will come in and put thousands of cores in a 42U rack for you... No, IBM's own P Series is a better idea, and their former x86 division (now Lenovo) looks even better.


Comment Re:Slashdot User vs. Average User (Score 1) 424

I would optimize for the Slashdot reader. We have higher incomes and we buy very, very expensive stuff at work. The revenue per ad on our ads is going to be several times better than the general public. And that translates to revenue per byte.

Of course, they have a lot of sunk cost in the bandwidth and capacity now...

Comment Re:Even AOL employees shunned it (Score 1) 461

Hmmm... I went to work for a bank in mid-1997 and this had already happened. This means one of two things:

1) I'm wrong. In which case, someone mod me down. But how could I have hallucinated this? I haven't even seen those people since I left, this wouldn't have been a "good old days" story.
2) Quick searching in google groups shows that was showing up in usenet messages circa 2002, but was showing up as a URL. Now maybe there was a mail server behind it, or maybe an MX record. I'm not sure how to do DNS Time Travel.

Conundrum. I'm too young for senility, and yet if it didn't happen then how could I...

Well, no emails in before 2007, in fact.

Most likely explanation - perhaps he didn't have a address, perhaps I just saw one in 06 or 07 or so and thought "well, that would have solved that problem". I can believe that. So, in full view of the entire internet... looks like I was wrong.

Don't sweat it -- it's only ones and zeros. -- P. Skelly