Posts by tonybarry

I'd like to see that hand made Mega Processor ...

The Mega Processor by James Newman deserves a special spot in the Centre for Computing History. One day I hope to see this amazing device and watch opcodes as they trudge through the ALU.

Best wishes for opening day.

I am having a difficult time with this announcement. I think most folk of average intelligence see through the hoax. So - who are the people presenting this, and what are they thinking ?

If they are taking the piss, then sure it makes sense. April Fool delayed due to calendar issues. But in their culture I thought they had minimal amounts of humour, especially when poking it at themselves.

If they are for real, then what are they thinking and how can they make such an announcement ? Are they trying for a scam ? Are they (to paraphrase Carl Sagan) people who see technology as magic, and use the rules of magical thinking as the foundation for their announcement ? If so, who fed them this line and how did they come to believe it ?

So many things that just don't make sense, from any angle.

Paper by McDowell on the effect of Starlink on astronomy work.

Starlink may not be helpful for astronomers in intermediate latitudes.

Paper by McDowell on the effect of Starlink on astronomy work is available here:-

https://arxiv.org/abs/2003.07446

Synopsis:-

[McDowell] discusses the current low Earth orbit artificial satellite population and show that the proposed `megaconstellation' of circa 12,000 Starlink internet satellites would dominate the lower part of Earth orbit, below 600 km, with a latitude-dependent areal number density of between 0.005 and 0.01 objects per square degree at airmass < 2. Such large, low altitude satellites appear visually bright to ground observers, and the initial Starlinks are naked eye objects. I model the expected number of illuminated satellites as a function of latitude, time of year, and time of night and summarize the range of possible consequences for ground-based astronomy. In winter at lower latitudes typical of major observatories, the satellites will not be illuminated for six hours in the middle of the night. However, at low elevations near twilight at intermediate latitudes (45-55 deg, e.g. much of Europe) hundreds of satellites may be visible at once to naked-eye observers at dark sites.

Disclaimer:-

I am not an author of the paper, am not related to McDowell or work with him etc. However I do engage in amateur astronomy when the clouds permit. Starlink stands to be a fecking pest if you are not interested in Starlink itself.

There are some things even a rat won't do

Java ? There are some things even rats would prefer not to do.

Mine is the coat with the cheese in the pockets. Hmmm.

CT may be harmful to your laptop

There have been reports of a computed tomography scan being harmful to pacemakers and other medical devices:-

https://www.hindawi.com/journals/crim/2009/189429/

And putting a laptop through CT is going to deliver a generous slug of gammas to a device that is not built anywhere near as robustly as an ICD / pacemaker. To get through the casing will require more MeV than through a person, and the flux density will be higher too.

Space based devices need to be hardened against radiation flux (although low-earth-orbit radiation doses to satellites over a unit lifetime are substantially higher than one single CT). Such protection is a whole study in itself, and requires a many-tiered response to prevent failures that can range from trivial to catastrophic. The catastrophic fails occur near power supplies or motors, where the battery charging circuits or the H-bridges to drive motors fail so that the power rail is connected to ground via a low impedance circuit. Rapid, untrammelled battery discharge is one especially unwelcome result.

https://en.wikipedia.org/wiki/Radiation_hardening

I whole-heartedly approve of the TSA's unrelenting efforts to keep us safe while flying, and will joyfully** endure the most undignified and invasive examinations to assure my fellow passengers that I have not shoved a bomb up my arse ... but I really do not consider this CT exam of my laptop a good idea.

Regards, Tony Barry

** well, joyful might be an inappropriate adverb. I am not gay enough to ever be joyful about such things. But it seems the TSA will leave no turd unturned in their search for explosive devices. I salute their zeal and diligence, and wish them the best in their fruitless cavity searches.

I'll second the motion. Kudos to SpaceX. Excellent engineering. If I were thirty years younger ...

The device sounds like an isolator, not a breaker. It will break on full current, but not pleasantly. It prefers to be operated at no load, to isolate the downstream devices which are already turned off.

Regards,

TB

Hi Trevor and colleagues,

Your article was a cracking good read, and the comments just as good.

It's a subject well worth discussing.

Regards,

Tony Barry

I have specified FTDI chips for over 10 years, since the first FT245 (USB<->parallel) came around with offerings from DLPdesign and Gigatechnology.

This renegade driver means I won't be specifying them any more.

While it may possibly be appropriate for FTDI's software to refuse to drive a module they did not author, it is not appropriate for them to render it inert.

Looks like the SiLab may be the necessary alternative, as the Prolific PL2303 driver will reliably reset MacOS if the device is removed while the serial connection is still active, and that really hacks me off.

Regards,

Tony Barry

Flip ...

Air pressure differentials are the reason for things being moved around by big winds. This can't be assayed too easily by eye (or what looks nice). It should be assayed by scaled wind tunnel tests. Driving this thing into a tornado without such tests is foolhardy at best and possibly tantamount to suicide.

While I applaud their willingness to die for science, it really is worthy of a Darwin Award.

Regards,

TB

Hi Pet,

The other article on ElReg about the SSL issues is here:-

http://www.theregister.co.uk/2014/02/23/apple_mac_os_x_10_9_ssl_fix/

and lists a website (gotofail.com) which will helpfully check your cert authentication process is actually working. I suspect that it is a much more easily crafted exploit than we might think.

Regards,

TB

Difficult to see this one happening

The ultrasonic comms seems a bit dubious to me. Average human hearing runs around 35Hz to around 15kHz (yes, the standard is quoted as 20Hz to 20kHz but few of us can manage that). So our speaker is going to have to run at minimum 15kHz to transmit the info. The data frequency will have to be subsonic ( < 35Hz) or else the sum and difference products will be definitely audible.

This implies the data rate on this proposed audio channel is around 2 bytes per second (12 bits per byte including start and stop bits). That is just a bit too meagre for any worthwhile comms. If it does happen, the data will have to be very compressed, like unix commands or suchlike. I can't see the value in that - and it opens up the rootkit to easily being analysed because the sonic datastream has to be minimally obfuscated.

The recipient PC needs some system (executing code) to convert sounds it receives into commands - which implies it has already been pwned. What then is the point of the sonic link ?

Difficult to believe this one.

Regards,

TB