Follow Slashdot stories on Twitter


Forgot your password?

Comment: Re:AGP not working with SMP (Score 1) 212

by TheRaven64 (#49559459) Attached to: Linux 4.1 Bringing Many Changes, But No KDBUS

Multi-core x86 processors only appeared well after PCI-E had taken hold

True, but SMP systems are older. I used a dual P3-700 for years, which I picked up cheaply on eBay because not many people searched for 'duel processor' (I think eBay now does some phonetic matching in their search). Before that, the ABit BP6 (1999) was quite popular. It ran two Celerons, so you could get a dual-processor machine for cheaper than a single-processor one (though you needed to run Windows NT or *NIX to be able to use the second one, as XP was the first SMP-capable consumer OS from MS). The 300MHz Celerons overclocked to 450MHz by bumping the FSB from 66MHz to 100MHz, making it quite competitive with the P2 (the L2 cache in the Celeron was half the size, but twice the speed, and the core was the same).

Comment: Re:edu-babble (Score 1) 329

by TheRaven64 (#49558665) Attached to: The Future Deconstruction of the K-12 Teacher
Really? Wikipedia tells me that kindergarten in the USA means up to age 6. By that time, I had been taught to read, write and do arithmetic (though I sucked at long division and found long multiplication hard until I was taught a third method a few years later). My handwriting is not much better now than it was then, though it did improve a bit in the middle as a teenager when I was writing on a regular basis.

Comment: Re:Z80 was in TRS-80 (Score 2) 117

by TheRaven64 (#49558639) Attached to: When Exxon Wanted To Be a Personal Computing Revolutionary

God I miss 80's computing.

I don't, but if you want to get the same fun without all of the old annoyances there are two things I'd recommend:

The first is to get an FPGA dev board. BlueSpec is a nice proprietary high-level HDL that is free for academic use, but if you don't qualify for that then CHISEL from Berkeley is also not bad - they're both a nice step above Verilog / VHDL.

The second is the mbed boards from various ARM partners. Some ARM folks handed me one of these to play with a few months back. These are aimed at getting embedded development to people who don't normally do it. They've got all of the fun I/O stuff from the BBC micro (plus some new stuff like USB and Ethernet) and a nicely put together development environment.

Comment: Re:Ah the Z-80 (Score 3, Insightful) 117

by TheRaven64 (#49558617) Attached to: When Exxon Wanted To Be a Personal Computing Revolutionary
They're increasingly hard to justify though. Cortex-M cores are really, really cheap (M0 and M0+ especially) and a modern 32-bit instruction set can be a significant win. You can't justify a 16-bit microcontroller on cost grounds anymore, let alone an 8-bit one. The main places Z80s are used is in systems designed in the early '80s that would cost too much to change, but which need periodic repairs.

I've seen a few things recently that have taken an amusing middle ground and bought ARM cores and used them to run a Z80 emulator, because it was cheaper to get the associated peripherals to attach to the ARM core.

Comment: Re:Google+ failed becuase it's GOOGLE (Score 1) 324

by TheRaven64 (#49558559) Attached to: Google Insiders Talk About Why Google+ Failed
I don't understand why Microsoft wants to go down that path. Their big money comes from businesses. They should be trumpeting private clouds (buy Windows server, install on a rack, run all of the cloudy stuff that you want under control of your company) and privacy to actively differentiate themselves from Google.

Comment: Re:Google Streams (Score 2) 324

by TheRaven64 (#49558545) Attached to: Google Insiders Talk About Why Google+ Failed
I've spent a depressing amount of the last couple of weeks looking at hotel web sites to find somewhere to stay for a business trip. About a year ago, almost all of them would have used Google Maps for their location page. Now about half used Bing Maps. I was quite surprised by this, though I vaguely remember Google starting to charge businesses for using GMaps (it could also be that Google highlights all of the competing hotels in the map, which probably isn't something that hotels want...). I didn't find the Bing map any worse than the Google one. Both were annoying in different ways.

Comment: Re:What we are seeing is ... (Score 5, Interesting) 324

by TheRaven64 (#49558537) Attached to: Google Insiders Talk About Why Google+ Failed

I expect Google to die in the same way that IBM died: it will still be a huge and influential player for a long time, but won't be the company that defines an industry that people care about. The same sort of path as Microsoft.

When I interviewed at Google a few years I was reminded of something that JWZ wrote about Netscape, claiming that it started to decline when it started hiring people who were there because it was a cool place to work, not because they wanted to change the world and believed in the things that the company was doing. Everyone I met at Google told me that I should would there because it was a cool place to work...

Comment: Re: and... (Score 1) 286

by TheRaven64 (#49551027) Attached to: Tesla To Announce Battery-Based Energy Storage For Homes
It obviously can be done, the question is whether it makes financial sense. It seems that, if it were cost-efficient to store electricity in LiIon batteries then the biggest buyers of them would be power companies, so maybe there's some market inefficiency that you can exploit by doing it in customers houses, but it even with that it sounds like it will have a very long ROI. I pay about £400/year for electricity (about $600). A $13K battery storage array would cost me the same as almost 22 years of electricity. Even if it reduced my electricity bills to zero, it would take 22 years for it to pay for itself. I think the overnight rate, if I switch to a tariff that has one, is about half of the normal rate, so it would actually take 44 years. Probably a bit less as electricity prices are likely to go up over the next few decades, but even with a 20 year ROI there are far better uses of my money.

Comment: Re:UK ISPs cause DoS (Score 1) 152

by TheRaven64 (#49550163) Attached to: Pirate Bay Blockade Censors CloudFlare Customers
Lawsuits don't have to be expensive, it depends on how much you're asking. If you claim, say, the cost of one year of Internet subscription then you're in the lowest bracket for small claims court filings (plus your time, which may be a lot more depending on how flexible your working hours are). The cost for the ISP to send someone is more than they're likely to lose, so you're very likely to get a default judgement against them. For added irony, you might ask for the ISP to be required to pay for you to transfer your subscription to A&A and pay the difference in the cost of Internet access for the next two years...

Comment: Re:Missing data point. (Score 1) 344

by TheRaven64 (#49543949) Attached to: Median Age At Google Is 29, Says Age Discrimination Lawsuit
If you think architecture doesn't change much over time, then you haven't been paying attention to architecture. Lots of data structures from 10-15 years ago suck on modern hardware because of changes in the relative costs of cache and branch predictor misses, and that's just on a single machine. When you get into distributed systems then the relative speeds of networks and local storage have changed dramatically.

Comment: Re:That shouldn't surprise anyone (Score 1) 344

by TheRaven64 (#49543913) Attached to: Median Age At Google Is 29, Says Age Discrimination Lawsuit

There's one more reason, which is that there are sometimes good reasons for writing your own sort routine. Specifically, if you have data that has a known distribution that lets you beat a comparison sort. One of the questions I was asked in a Google interview was along these lines. The point was not to see how well I could write code on a whiteboard or reproduce an algorithm from a textbook, it was to see if I could understand that the problem wasn't the same as 'sort arbitrary data', see if I could extract what properties of the problem made it amenable to optimisation, and see what tools I had for approaching that kind of optimisation.

And sometimes it's not about knowing if you can reproduce an algorithm, but about knowing whether you understand the limitations of a particular approach. Do you understand when that off-the-shelf quicksort library would do a terrible job on certain input data? In one interview, I discovered that my interviewer didn't know about hopscotch hash tables, but did know about cuckoo hashing, so we ended up with a discussion about what the overheads of the two approaches are and when either would be better.

"Consistency requires you to be as ignorant today as you were a year ago." -- Bernard Berenson