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I prefer my turkey ...

lowen Re:Conventional roasted but want to do a smoked on (189 comments)

I've done the turkey smoking for eight years, now, and wouldn't have it any other way. I use a Chargriller 2121-style barrel grill; the bird goes on one end over a drip pan, and the fire goes on the other end. I start the fire in a chimney starter at 4:45AM; the coals go on the grill at 5:15AM along with pre-soaked apple, cherry, and pecan chips/chunks; damper to low, exhaust full closed; bird goes on the grill when the temp gets down to 225F (typically about 5:50AM). Keep the coals stoked and the temp at or around 225F until thigh joint is at 170F and the breast is at 165 (an 18 pound bird will take 6 to 6.5 hours at 225F). Cover with a tent of aluminum foil once the skin is the desired color, and keep the cavity full of liquid of your choice (I use a mix of one part Vernor's, one part white grape juice, and one part apple juice).

A 6 hour cook time gives a 12:30-1:00PM carving time (the meat absolutely must rest at least 15 minutes before carving, preferably breast down).

about two weeks ago
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David Klann Talks About Using Open Source Software in Broadcast Radio (Video)

lowen Transmitter manufacturer (35 comments)

Hmm, the transcript says 'Nortel' but it's actually 'Nautel'. They make good transmitters, and have for a very long time.

about 4 months ago
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How Vacuum Tubes, New Technology Might Save Moore's Law

lowen Re:The problem is not switch speed (183 comments)

One of the problems with increasing clock speed is gate capacitance and the RC time constant charging curve causing the switching FETs to operate in the linear region, causing power dissipation to go up with clock speed. This is why a decrease in process size has typically yielded a corresponding decrease in power dissipation at a given clock speed.

If you make the capacitance smaller, you can increase the switching speed (capacitance would decrease with the square of the feature size (gate capacitance is dependent upon gate area), wheras resistance would increase linearly, inversely proportional to feature width, assuming the feature depth doesn't change (resistance dependent upon cross-sectional area)).

Another poster has already mentioned asynchronous designs, so I'll pass on that particular nuance.

But clock propagation is a serious issue, and I can see a vacuum transistor improving this considerably.

Now, figuring out how far a wavefront will propagate in some period of time isn't too hard.

Undoped silicon has a relative permittivity of 11.68; the reciprocal of the square root of the relative permittivity is the velocity factor of a particular dielectric; for undoped silicon that's about 30% of c. Silicon dioxide, as used for most of the insulation on the typical MOSFET design, has a relative permittivity of 3.9 and thus a VF of about 51%. On a stripline laid on silicon dioxide (silica glass) the velocity of propagation is about 153 million meters per second, or 153 meters per microsecond or 153 millimeters per nanosecond or 153 microns per picosecond. 153 microns is a bit larger than the cladding on a typical fiber optic strand (most have a cladding diameter of 125 microns; OM1 multimode is 62.5 micron core/125 micron cladding, OM4 is 50 micron core/125 micron cladding, and single-mode is 8 micron core/125 micron cladding, for comparison). That's best case propagation time.

Now, to see how this translates to something of today, at least one of the models of the latest Haswell-DT Core i7 chips has a die size of 177 square millimeters. The chip is not square, and seems to be about a 4:1 rectangle in photos, which would yield about a 6.5 mm by 27.25mm die (yes, I know that gives 177.125 square millimeters; close enough).

Now, if a clock signal needs to go straight across the narrow portion, it will take about 42.5 picoseconds to do so, assuming transmission across silion dioxide alone. Propagation in the long direction would take about 178 picoseconds to do so, with the same assumption. The published top speed of this processor is at the time of this writing about 4.5GHz (I know it's a bit higher, but that's a moving target). This is a 222 picosecond clock period; easily doable in the short dimension, a bit more difficult in the long dimension, and probably already requiring some asynchronous elements and delay compensation. If you limit solely on clock propagation time, and are able to work in a slip of a full clock cycle, the long dimension will give you a limit of a bit over 5.5GHz; the short dimension will similarly give you a limit of 23.5GHz.

That's drastically oversimplified; each gate has it's own propagation delay that must be figured, and there are four cores (which makes it pretty understandable why the chip would have a 4:1 die dimension ratio, no?). A 20% clock delay factor will allow, with care, a good chance for synchronous operation (42.5 is pretty close to 20% of 222), but that's assuming straight clock traces (and they are not just straight across the chip).

Food for thought.

about 6 months ago
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Belief In Evolution Doesn't Measure Science Literacy

lowen Re:Wait a sec (772 comments)

1+1=10, sorry.

about 7 months ago
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Fixing the Pain of Programming

lowen Re:Debuggers (294 comments)

Heh. In intercal, the "Hellow World" debugs you.

about 7 months ago
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Programmers: It's OK To Grow Up

lowen Re:most young developers are at least as bad (232 comments)

Hmmm... Windows is over 20 years old, yes? So is Unix, no? Mice, keyboards, VGA, USB, Dynamic RAM? LCDs?

What about C? Or x86 assembly code (with extension in the _64 variant)?

The ATA disk drive standard?

And what about TCP/IP, even IPv6 is nearly that old, no?

about 7 months ago
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US Nuclear Missile Silos Use Safe, Secure 8" Floppy Disks

lowen Re:Are there any old drives around that read these (481 comments)

I seem to recall from my BIOS writing days with CP/M, that the 8" drives had twice the data rate of the 5" drives. They also spun faster, 360 RPM vs 300 RPM. The 8" IBM format was soft sectored 26 sectors of 128 bytes, and the 5" used 16 sectors of 128 bytes or something like that. too many numbers to remember.

Right, for the 360K double-density 5.25.

Like the 8 inch System/34 format, the 5.25 high-density drive in the PC AT also ran at 360 RPM instead of 300, and had double the data rate of the double-density 5.25 inch drives, yielding exactly the same number of sectors per track, with the only difference being that the 8 inch has 77 tracks and the 5.25 HD drive has 80.

about 8 months ago
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US Nuclear Missile Silos Use Safe, Secure 8" Floppy Disks

lowen Re:Now was it ... (481 comments)

By the time double-sided drives came out the FM-encoded IBM 3740 format had been pretty much superceded by the System/34 MFM format.

about 8 months ago
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US Nuclear Missile Silos Use Safe, Secure 8" Floppy Disks

lowen Re:Security through Antiquity? (481 comments)

50 pin Shugart would be the most useful, unless you really really need DEC RX01 or RX02.

about 8 months ago
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US Nuclear Missile Silos Use Safe, Secure 8" Floppy Disks

lowen Re:Now was it ... (481 comments)

Well, in my experience the good quality double-sided drives are more reliable as they age. The reason being is that a single-sided drive has a rather critical piece of felt as a pressure pad on the top surface, and those pads are notorious for the glue holding them to the head carriage drying out and causing them to fall off.

Double-sided drives, on the other hand, have an actual head on the top surface and those tend to stay put.

about 8 months ago
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US Nuclear Missile Silos Use Safe, Secure 8" Floppy Disks

lowen Re:Now was it ... (481 comments)

While the photo in the article is a bit grainy, judging from the location of what appears to be the index hole they're double-sided.

about 8 months ago
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US Nuclear Missile Silos Use Safe, Secure 8" Floppy Disks

lowen Re:Are there any old drives around that read these (481 comments)

I've got to see pics of that, as that would be one rare 4P (I have two in my office right now.....). The case after all only allowed two Tandon TM-50 single-sided 5.25 drives to fit.

Now, the Model II had a single internal full-height 8; the 12, the 16, the 16B, and the 6000 had two internal 'slimline' 8's.

And 8's were the most common for the various CP/M boxen. Side-by-side 8's fit quite nicely in a 19 inch rackmount chassis, such as several boxen by Altos.

Then there were the RX01 and RX02 drives for PDP 11's.

about 8 months ago
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US Nuclear Missile Silos Use Safe, Secure 8" Floppy Disks

lowen Re:Floppy drives? (481 comments)

Hmmm.....

I know this is opening things up for lots of bad jokes..... but, it really boils down to whether the cookie's lubricant is still effective at allowing the cookie to spin to the correct RPM, +/- the FDC's tolerance. And that is dependent upon the storage conditions (mostly humidity) and the media quality. Being in a military application, this media is likely the most expensive made, if not the highest quality.

Yes, the actual magnetic media is called a 'cookie.' And the word 'cookie' is a bit more difficult to twist into a bad pun.....

If the dry lube used in the oxide coating on the cookie has become ineffective, then there will be a rather distinct screeching sound as oxide (and your data) flakes away. There are techniques to overcome this with bad media; however, back when 8 inch media was common it was also far higher quality that the cheap 5.25 media of the 80's was, and those 5.25 diskettes are the ones that have given my data recovery attempts the most difficulty.

about 8 months ago
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US Nuclear Missile Silos Use Safe, Secure 8" Floppy Disks

lowen Re:Are there any old drives around that read these (481 comments)

Yes, there are. I have one, and a Catweasel controller that can read and write basically any format on it.

The 8 inch standard format is very similar to the 1.2MB 5.25 inch format. Actually, it's the other way around, as when IBM built the PC AT and the high-density drives for it they apparently intentionally made the formats nearly identical. They're so close that computers that use 8 inch diskettes can typically be modified to run with 1.2MB HD 5.25 drives and media with only a new controller to drive cable and new drive power supply (8 inch drives typically take either AC mains power to run the spindle or 24VDC, and 5.25 drives take 12VDC to run the spindle). See http://nemesis.lonestar.org/co... for some tech info on how to do this with one of the first multiuser 'personal' computers, the Radio Shack TRS-80 Model 16 (and descendents the 16B and the 6000). Also see http://www.dbit.com/fdadap.htm... for the 'proper' adapter board.

8 inch diskettes are famously reliable with good quality media, and the bits aren't packed so densely that an EMP event will wipe them out, as long as they're in a faraday cage with sufficient attenuation and power handling capacity.

Current production high-density PC FDC's can easily handle the 8 inch drive with the proper adapter cable, but the number of supported formats is small. More flexible is the USB interfaced Kryoflux, and the PCI Catweasel MK3 and MK4 (the Kryoflux is currently in production and available for purchase; the Catweasels have been out of production for a while and are a bit difficult to obtain last I checked; I bought my MK4 from amigakit.com, but they appear to only have the Amiga-specific MK2's in stock.

about 8 months ago
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A Call For Rollbacks To Previous Versions of Software

lowen Re:Computer Science != Software Engineering..... (199 comments)

SE majors learn the how and why of release management, that's why it's relevant. IS majors learn business processes, and those tend to include release management and the importance of rollbacks.

about 9 months ago
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A Call For Rollbacks To Previous Versions of Software

lowen Re:Devs don't want to maintain old versions (199 comments)

It goes deeper than this.

Businesses have to pass down the costs of software maintenance to consumers; consumers won't pay what it actually costs to do this at the device level.

For servers, that's why you pay extra for long term support at a particular stable revision. See Red Hat Enterprise Linux and Ubuntu LTS, or Microsoft's long term support for older versions of Windows Server, for reference.

Developers of course would prefer to work on 'sexy' things like new features; maintaining older versions and backporting security updates and bugfixes is decidedly 'unsexy' in comparison.

about 9 months ago
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Is Analog the Fix For Cyber Terrorism?

lowen Re:This is very, very old (245 comments)

According to the ACM (you know, the experts in this topic), there are five basic courses of study:
Computer Engineering (making the hardware)
Computer Science (designing the algorithms)
Software Engineering (release processes, patch management, etc)
Information Systems (translating business processes to code)
Information Technology (putting all the pieces of the system together an maintaining the whole lot).

You can read more at the ACM (Association for Computing Machinery) at http://www.acm.org/education/c...

about 9 months ago
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Is Analog the Fix For Cyber Terrorism?

lowen Re:Stuxnet (245 comments)

Make sure you refresh those PROM's if they're EPROM or EEPROM (the absence of a window is no indication that it's a real fusible link PROM; it could be OTP UV EPROM in there). There is a thing called bit rot that occurs with most EPROM/EEPROM/Flash technologies where the isolated gate's charge bleeds off over time; 20 years is fairly normal, but 30 and 40 year old EPROMs (1702, 2708, and 2716 era) are beginning to fail all over. Search through the http://www.vintage-computer.co... forums as well as read the Wikipedia article ( https://en.wikipedia.org/wiki/... ) to learn more.

Mask ROMs are better, but not perfect. If the package is a 40 pin DIP it's almost sure to be flash, and that will bit-rot over time.

One more item on the checklist are those old paper caps that need to be replaced by X-class film on the inputs to power supplies. Again, the Vintage Computer forum is a great resource for information on how these things fail.

Also any batteries for NVRAM, like the ubiquitous Dallas Semiconductor devices, many of which are soldered in place. Or soldered in Lithium primary cells. Or like many older PC motherboards that have NiCd or NiMH cells that are both soldered in and leaking electrolyte. We have some Proteon routers (cisco's competitor back in the day) that have their NVRAM as low-power CMOS statis ram with a large bank of NiMH cells on a multibus card; they've long since lost any ability to retain charge.

As electronics age, lots of issues arise, and anyone who maintains such a system needs to see how others are handling the failures in these sorts of systems; again, the Vintage Computer forum is a great resource of talented people who are dealing with equipment of the same age. I know of many systems, particularly scientific instruments, where the controls are things such as a VAXstation 4000/90 connected to a SCSI CAMAC crate with wirewrapped boards, and VME Sun 2 and 3 series workstations controlling the whole lot. Keeping an aging VAXstation with VMS 5.2 or similar vintage running, with those old DEC StorageWorks 2GB and 4GB narrow SCSI drives, is a bit of a challenge, but when you have custom controls for multimillion-dollar equipment with no spares budget or major research instrumentation upgrade grant you have to get creative. (No, you can't just throw a PC in there, since the entire system's calibration depends upon the whole system timing and not just the actual platform). This system is being upgraded (there was even slashdot story about the upgrade at http://science.slashdot.org/st... ) but it's expensive to do things to the precision required.

Also, if the system uses GAL's or EEPROM-based FPGAs/CPLDs this is also something to make sure you have backups of the logic (JEDEC files, typically). Even fusible link PALs can go south. And be sure to have a stock of replacement chips, since many if not most of those older devices are long out of production.

Lots of test equipment is in this same boat, with expensive instruments like spectrum analyzers and the like running embedded MS-DOS and Windows on hard drives that are going on 20 years old. And, yes, in many cases they are consumer hard drives (I just looked at a very expensive 'multipath fading simulator' device, and it has a 6.4GB Western Digital Caviar drive in it.... you remember those? And one instrument I haven't looked into in a long time uses a 170MB Micropolis 5.25 full height ESDI drive.....

about 9 months ago

Submissions

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New VMware doesn't need OS, avoids Linux issue?

lowen lowen writes  |  more than 7 years ago

NotAVMwareEmployee (10529) writes "VMware has announced on their website a new ESX product, known as ESX Server 3i, which does not require a general purpose OS to run, load, or manage the hypervisor, but has a hypervisor that loads and runs right down on the hardware, with a remote command line interface. Could this be a response to the questions raised about ESX's vmkernel being a derivative work of the Linux kernel?"
Link to Original Source

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