* Posts by Trevor Gale

23 posts • joined 23 Feb 2012

Da rude sand storm seizes the Opportunity, threatens to KO rover

Trevor Gale

Re: A place in history

Oh come on, let's at least be reasonably modern and up-to-date here, and speak of *real* computers: my first home 'pc'* had a 1.4uS cycle time, (clock in the upper KHz ranges) and we spoke of *words*, not 'bytes'. Okay it was 16 KILOwords but at least it wasn't based on any of these transistor-type things, and it kept its data even when the power failed - without one of those funny coin-shaped batteries. Well, as long as you didn't head-butt it or drop it on the floor, so I suppose it might not have survived a typical launch...

* PDP-8/e with 16K 12-bit words core memory, TTY interface, mag tape i/face + magtape drive, 512-head drum memory, home-brewed executive and OS on top + various home-written programs (no games!) to go with that! Oh yeah, later on a VDU to replace the Teletype!

Chaps make working 6502 CPU by hand. Because why not?

Trevor Gale

Hand-assembled Code

Some 35 years ago I had two (yes, 2!) PDP-8/e computers with a tape drive, disk drive (cabinet one, all of 10 MEGAwords!), printer (line), and a couple serial lines - one a VDU terminal and the other an ASR33 teletype - as a home system!

I already knew assembler, for the 6502 and the 6800-series processors, but I had no OS or anything for the PDP's. So I set about writing one, so that I could end up using these machines for processing radio propagation data from regular observations. No development tools, just the PDP-8/e manuals and codes.

Fisrt I had to write a bit of code that would take serial characters as octal input (it is a 12-bit machine) and write this word into successive memory locations - this was done using the front-panel switches, word by word.

Then it was time to write some code that would allow me to write whole segments of octal from the keyboard of the serial device I chose, usually the VDU terminal. The next bit of octal 'code' was a routing that would take that segment and write it to the magtape as a record, skipping till after a 'long gap' on the tape so I could eventually load back these segments one at a time how I wanted.

Once that was done the 'semi-serious' work began - first of this was actually to *write an assembler*, which for this machines' instruction set and layout was not too complicated. This assembler, a 'program', was written to a new magtape and also to two copies (play safe here!) of punched-paper-tape.

After that, the assembler was the main tool to write I/O routines for the magtape (proper, better), the disk (elementary), and the printer. Once that was completed the 'really serious' work began, I wrote an executive, then a filing system of my own, then an operating system on top of those.

Finally I had a running system with storage volumes (floppy disk never got added but all principles were in place and it didn't make any difference anyway), and with interfaces to assignable peripherals (e.g. equivalents of mount and unmount and different peripheral classes and parameters) - and I did go on to write some of the programs I ran to do the original work I wanted to do.

Eventually the "common" P.C. came along and was easy to interface with the radio hardware I used, plus it used a LOT less A.C. power than the roomfull of computer gear that was the PDP's, so eventually I got rid of most all of that equipment as there's a limit to how much one can keep, at least in the 'sane' world.

Still, even as I look back all those years, I'm sure that I learned quite a lot and gained a valuable insight into what certain colleagues of mine have to do in their work and where the 'trip-up-points' can be lying around; in any event it was definitely a memorable experience at the raw end!!!

Trevor Gale

Re: Michael Strorm & herman (thermionic valves)

25kW seems a bit much - if it was this then it equates to around 6.172W per valves, and typically that'll be 1.89W for the heaters (filaments) and 4.282W for the logic per valve. So it'd be 7.654kW total for heaters, and 17.346kW for logic. Assuming +170V as +ve rail for valve anodes, that'd make around 25mA anode current for a triode (and I'm assuming heaters/filaments at 6.3V, 0.3A for the rest) all as averages.

You could do logic switching using triode valves with a lot less than 25mA anode current - 2.5mA would be more typical. Remember, a power output valve might handle 6 - 9W in a typical valved radio of the time, and for the logic levels we don't need that power. So we'd be looking at, say, 0.43W for logic and 1.89W for heaters giving a total of 2.32W per valve total, requiring 9.4kW for all the valves...

Admittedly I'm looking at more recent technology here, like double-triodes on a B9A base such as the ECC83 and its data from around 1953, but even the earlier (double-)triodes in octal bases (physically larger devices) would fall in a similar ball-park.

Uncle Sam's boffins stumble upon battery storage holy grail

Trevor Gale
Joke

Re: Regenerative towing?

That'd give a new interpretation of 'one for the road'... (legally!)...

Colin: "Sorry mates, can anyone help me, me battery's gone right flat?"

Joe: "There's little blue pills you can get for that mate!"

Colin: "No, I don't mean that, I just need to get home."

Joe: "Ah, you don't want to keep that sort waiting!"

Bob: "Hey, Colin, I can hook you up okay, gotta be on my way anyway. How far?"

Colin: "It's 15 miles home but if that's too much it's only 10 to my bit on the side."

Bob: "No problem mate, I've got some ropes in the back and 10 miles ain't too far."

Colin: "Ta, don't get me wrong, I've already pulled but we're not into the kinky stuff".

Bob: "Oh okay then, I can get yer home, 6 pints of the high-octane stuff okay?"

Colin: "Yeah fine, I'll bring it round tomorrow. Tell me better half we've been playing golf ok?"

Bob: "Yep, no worries. Ya can bring a funnel with it yes?"

Colin: "Yeah. It's all the 'extra commuting' that's done it, never had to get a pull before though."

Philae comet lander officially dead

Trevor Gale

The science of beauty and humanity combined

This project is a beautiful example of what can be achieved with the combined efforts of so many people from various companies and disciplines working constructively together in detail for such a long period.

It's actual journey began in 2004 with the launch, but although not so prevalent in the media for us to read much of the work was really put in way before this, with the original planning and assignment of different parts of the project, with the design of the instruments and the flight platform, the matching for and the organisation of the launch, setting up of global cooperation, the extremely tough pre-launch testing and more. So many people from various institutions and different companies with contracts working together under the umbrella of ESA to realise the final craft ready for launch.

So there it was back in 2004, some 1200kg plus around 1700kg of fuel for its journey - and little Philae at just 100kg incorporating 10 scientific sensors and instruments - and that journey had to go right on track for over a DECADE to arrive near the target comet, with all the risks and unknowns on the way.

Then to top all of that, to let off Philae to land on that comet from an altitude of 22km - through all sorts of 'nasty stuff' that the spinning comet might be throwing off, with virtually no steering(!), aiming for a carefully spot to make for a landing that could be survived intact ... yes, it all came together!

The scientific returns and the images that were sent together are so revealing, allowing a degree of understanding while giving rise to a few more questions: such is the nature of the best of human exploration.

I do sincerely hope that some of these results, these puzzles, these images, cause more younger people to follow an education which leads them into various fields which can contribute further to human discovery and exploration - it is knowledge and understanding (of all sorts) which enables the development of a better life for all human kind.

Don't Fedex your tapes, people! We're so fast it's SANdulous – WANrockIT

Trevor Gale

"I cannot remember a time ... when any networks had a higher bandwidth than the movement of contemporary physical media."

One has to add in the time taken to transfer all of this data to the physical media concerned, which might not be insignificant - before there's anything to move / transport.

Put your private parts on display if you want to keep earning a living

Trevor Gale

Re: On the other hand ...

Re: On the other hand ...

Clearly I am also an ElReg reader, and I do own and use a darkroom timer. I mostly use it in my own darkroom, developing B&W film and sometimes still colour C-41 film too, 120-rollfilm from my Mamiyas.

Not that I'm "anti-digital" at all, apart from my Canon EOS that darkroom timer is my own design and uses a 6809 microprocessor with memory and I/O etc. to save my typical process times and so on.

You see, electronics is applied in my darkroom, although the art of winding rollfilm onto the dev-tank spirals is all in the wrist action, done while sitting down with the important bits on my lap... ...

Anyone using M-DISC to archive snaps?

Trevor Gale

Re: Solves only the easy problem

"a volt is still a volt"..."relatively easy to reverse engineer an interface." - While that principle might hold true, in practice it might be a well that's just another 50-foot hole in the ground, not much use to a man who'se moved to the desert.

There's still some peripherals that need really old computers - on the edge of dying - because they use ISA interface boards... anyone tried reverse engineering those to a modern PC motherboard recently?

Pro tip: Servers belong in dry server rooms, not wet cloakrooms

Trevor Gale
Happy

Re: Backup

While the secretary went "boing, boing, boing" every morning? ;-)

Trevor Gale

Re: £300 per hour for starters

In your case it may well have been a piece of the proverbial, but it is different when things look that way but there's an adder under the grass - you won't catch that but a solicitor will, perhaps even saving you half or more of an entire estate! You won't know that until you're well in it... then you might think a quick telephone call to the solicitor will clear up your question, and be surprised to receive a significant invoice for thier fees - again, they'll have given you information over the telephone with minimal information about the whole case.

NO - I am not a solicitor nor is anyone else in my family a solicitor, however I have received their services and seen some of the work that went into it and so appreciate what I paid for.

Windows 10 in head-on crash with Nvidia drivers as world watches launch

Trevor Gale

You should remember even further back - 'cos it's the Intel mobos that sit around with limited IRQ possibilities.

The 'real-deal' PC would have had a 68000-family CPU with quite a few 68k peripheral chips, then we'd have had a 'proper' PC AT, gone on with clones, and then further into better machines.

Nice lots of IRQs at different (programmable) levels, and (gosh!) LOADS of nice linear address space... none of this segment rubbish.

Pity that the right people weren't around at the right time (and don't tell me Apple were, their market approach was 'different' shall we say).

Roll up, roll up, for the Meta35: The hybrid snapper's data dumpster

Trevor Gale

Re: A very strange product

With the market aim I'd be tempted to ask why this product isn't also designed for Win98SE and WinXP... ;-)

However more seriously if they've gone to the bother of designing interfaces for various 35mm cameras, then (with all respect for LF users) why on earth not for the Medium Format users of 120-rollfilm cameras such as the Mamiya RZ-67 or the Mamiya 645 Pro?

I would think that with people concerned with the quality of film that there are many users of Medium Format (percentage-wise of say 10 years ago) compared to the same reckoning for 35mm users.

WOODEN computer chips reveal humanity's cyber elf future

Trevor Gale
Boffin

Re: A couple of concerns:

Non-critical consumer and low-frequency 'economical' circuit cards (e.g. parts of a television and of audio amplifier boards) are made from SRBP (super resin bonded paper) but this material is totally unsuited to high-frequency or high-density boards, where FR4 epoxy-fibreglass is used or even ceramics for SHF / microwave circuits.

One won't find many SRBP cards in an average desktop PC either for the same reasons.

Printed circuit substrate properties such as thermal expansion, dielectric constants, physical stability, copper / gold bonding strength and processing tolerance (chemical and thermal) are vital considerations especially as one drives higher in the frequency and density domains.

There is no 'fits all sizes' material for PCB manufacture.

Snakes on a backplane: Server-room cabling horrors

Trevor Gale

Cable and Job disaster - nearly!

One system operator nearly lost his job due to such a nightmare - by being thoughtful and diligent. Under the false floor in a particular systems room ran a plethora of RS-232, 10-base-5, r.f. telemetry coax, and proprietary disk interface (yes, disk cabinets), together with untold kilometres of used/unused old cables. An operator was on duty for that room 24/7.

Whenever this one fellow was on night duty there would often be unexplainable major disk failures that would bring one or more of the systems down. Only when HE was on duty, not when some other operator had that lovely quiet pastime with the odd beer or two. Clearly it was thought that this poor fellow was doing something he shouldn't, perhaps purposely to add some excitement to his time.

As it turned out after a long study of his work it WAS due to something he did...

One night accompanied by a colleague, nothing went wrong. Next time he was on his own, damn, down went the disk and a system again. So he was of course called in for a 'disciplinary talk' and to account for his every action during his night shifts: he explained that he was very consciencious, took everything very seriously, why, he even went around the room at intervals to make sure there were no important error indicators showing. And no, he didn't bring beer or suchlike into the room. Following night he demonstrated exactly what he would do right through a shift - under supervision. There wasn't any 'chat' with the supervisor like there had been with his colleague, and after an hour or so he went walkabout around the room to check for any error indicators - and THERE! A disk went offline and brought a system crash! All without doing anything actually "wrong". The following day all was examined around where he walked, and finally the edge of a disk interface cable was found trapped between the corner of a floor tile and its support, as soon as any pressure was applied to that tile it would short out a couple of wires within that cable, bringing the disk down. So he was eventually exhonorated, and kept his job, after spending a month or so under the threat of suspension or worse.

He was very lucky since he already had a reputation for the occasional accident, e.g. you'd avoid the corridoor if he was walking along it carrying a tray full of coffee from the machine!

El Reg chefs whip up Post-Pub Noshographic

Trevor Gale

Re: The most astonishing thing about this series is ...

When I worked there were (very rare, of course) times when the occasional TGIF evening pub sessions took place.

Post-session concerns weren't so much about diet but more about making sure you were fit and prepared suitably for the 'other' kind of pleasures to compensate for the extraordinary amount of excessively hard work you'd just accomplished.

Dishes, diets, food... that came way later!

Come on folk - get your priorities right... El Reg could do a much more valuable series on ensuring 'post-work satisfaction'!

The coming of DAB+: Stereo eluded the radio star

Trevor Gale

Re: If you have an old DAB,

Quite a few people can, I imagine. (See my other post nearby on this). Again, when I was a tad younger I could even tell you, whilst walking along the pavement, if someone was watching 405-line TV or watching 625-line TV by hearing the line-transformer drive, which was of course a somewhat distorted at 10,025 or 15,625 Hz respectively!

Trevor Gale

Re: If you have an old DAB,

Okay, I'd maybe doubt 22,050Hz, but be careful - it could be a harmonic of 11,025. That is a frequency which, at 60 years old, I can still hear perfectly well: indeed I can still hear (just) the 15,625Hz *sinewave* of a locked line oscillator (not one in an old TV set, but one for use in other PAL electronics).

When I was much younger, I could sure hear much hihger in frequency...

British boffin tells Obama's science advisor: You're wrong on climate change

Trevor Gale

Re: Boffins disagreeing with each other? @ icetrout

I'd sure agree with the idea that coal-fired plants do generate a lot of sulphur and other serious pollutants - AND that nuclear power is a FAR cleaner and safer technology for energy production. The problem with it is down to ill-informed and non-thinking slices of society raising groundless objections, in the similar way to their extremely loud backing of 'wind farms' and solar panels... whilst the provable, measureable truth shows the opposite, which they naturally choose not to believe. To wit:

[1] - The oft-shouted issue of nuclear waste is not an issue at all, if one looks at various sites around the seas one finds a good deal of deep chalk/salt rock which can safely accomodate the waste from nuclear plants way into the future;

[2] - Wind turbine 'farms' are far too inefficient and brought into a falsely 'good' light by over-the-top subsidies at the cost of the normal energy consumer. Individual turbine generators can be shown to be something in the order of 12% efficient from input to output, and on top of this one has to add the high maintenance costs and capacity smoothing to cater for wind variation;

[3] - Whilst the efficiency of conversion in solar panels has increased in the last decades it remains problematic in the distribution area, and for small / family installations the initial install requires a decade or more to fund. In larger cases the variation in 'visible' solar radiation impacting the panels means, again, the need for capacity smoothing;

[4] - So many calls for a 'cleaner environment' are based upon the reduction of CO2, the truth is that the levels of carbon dioxide we observe have been fluctuating widely for centuries and we can measure such variation thousansd of years further back, due to natural cycles of various origins. Never forget the relationship between foliage and CO2: take all the CO2 away and the forests will disappear. Likewise, cut the forests and the CO2 will increase. There's a lesson there before listening to the 'climate change' believers.

Quick Q: How many FLOPPIES do I need for 16 MILLION image files?

Trevor Gale

All these storage devices, and yet nobody seems to mention the ultimate - not a disk but a SOLID STATE STORAGE DEVICE with NO BATTERY so could last for absolutely ages. Way back when, I wrote an executive and a primitive operating system of my own for a PDP-8/e, a 12-bit machine with a magnificent 32 KILOwords of memory all-told, in the form of CORE MEMORY. Oh yes, it also had punched-card as a storage medium, but I still have one of the 3-board core memory units and that'll still have some of my code in it from the last time it ran (30 years ago, and it was a 'home' machine!) unless it's been seriously banged about.

Yes there was already a DEC operating system but I wanted a thin, close-to-the-metal one for my radio-related activities Eventually it got a 1-Megaword DRUM which had 128 heads, damned fast that was!

10,000 km road trip proves Galileo satnav works, says ESA

Trevor Gale

Re: Does this mean@Randolf McK

<< "Err, it's nothing to do with bouncing signals off the Sun"

< You're new round here, aren't you?

No, and it's bad form to suggest sarcastically that the poster is 'new round here' - in any case, the working of this system has absolutely nothing to do with bouncing signals off the Sun, which would be an idiotic idea anyway.

The working method employed by the system, also in use by other such services, provides not only accurate navigation information but also accurate time information and these two services, completely independent of each other, rely upon one common factor - a known orbital distance. This is based on the orbit of the Moon, which is (a) very well defined and (b) not subject to the major disturbing effects that random sunspots and solar storms cause. Provided at least one of these types of satellites can 'view' the Moon, it 'echoes' a signal from it to measure it.

Some people might think that can't work because sometimes the Moon isn't in the sky, but the satellites use a special, powerful laser on a motor-driven beam to send infra-red light around in the sky until the Moon is found, again not relying on sunlight in any way.

The services have a great up-time, the only time it cannot be provided is during a lunar eclipse (since the Moon is actually offline at such a time) or during February 29th in a Leap Year (since that is an unpredictable day during an abnormal year).

I do wish some people would treat serious scientific discussion more respectfully.

Friends don't do tech support for friends running Windows XP

Trevor Gale

Re: If they have to buy a whole new machine...

Whilst I avoid MS Windows OS and MS applications in general (my desktop(s) and others are Fedora Linux) I do take issue about PLC and FPGA, and PLA devices and programming. Yes they are 'text-driven', but that's fine as far as it goes. Once you've defined your states, rules and equations and written them all nicely into a (text) file, they have to be compiled - using a tool. The output of that tool is another recognised standard format file. Then you have your device programmer peripheral and its interface; these last two things are often only supplied as or with drivers and packages that are based to run on an MS Windows OS. I don't care much about a GUI for using these, but that's how they're supplied... and I spend enough time designing prototypes such that I don't particularly wish to chuck loads of stuff down the bog and scratch around endless forums to find a new set of tools that just might do what I'm already used to doing. That doesn't make me an idiot: it makes me one of many sensible hardworking Engineers.

Twenty classic arcade games

Trevor Gale

Galaxians / Space Invaders

The game Galaxians (very similar to Space Invaders but not the same) was what stopped me drinking too much Guinness and eating too many beans-on-toast snacks in a local 'pub' after I left England! We even had a kind of 'league', once I reached the limit of 32,767 points before they did an update for that!!!

OPERA grabs spanner, fixes kit, and slows down neutrinos

Trevor Gale

Engineer

The explanation of this 60nS difference between the expected 0.0024S (2.4mS) over 732kM and the 60nS 'earlier' detection would imply, if in error and expressed in distance terms, a reduction of 18 metres in optical fibre. Were this detection to be propagated to the final measurement apparatus using co-axial cable transmission line then of course an error of matching such cable to its source, or from the cable to the receiver, could easily realise a significant time error due to delay, reflection and velocity factor compensation, but to 'see' this magnitude of error in optical cable would imply that the length of said cable was thought to be maybe 18m longer than it is. Of course a fraction of the error could be accounted for by the reflection etc. due to a misplaced connector but this can't be 60nS. As many R.F. engineers can show, normal equipment design at microwaves (e.g. 24 GHz) can involve the matching of several amplifiers to a single output in order to realise a higher output power than one amp. alone: to do this the impedances of the amplifier outputs have to be correctly matched as does the load - this is done with transmission-line techniques to get phase coherence between amplifier outputs. At 24 GHz, a wavelength is 299792 / 24^3 MHz = 12.5mm; 20 degrees phase inaccuracy (meaning some 0.48dB power loss in each arm) would be 0.69mm / arm (not accounting for velocity factor in the substrate), and assuming 8 such amplifiers are combined (the practical limit, do the maths) that'd be a cumulative loss of 2.88dB, nearly half (-3dB) of your power! Since such engineers successfully design combiners with less loss than this one expects that the engineers and physicists at CERN knew of the error sources within their measurement apparatus and where they could occur. Mistakes of the magnitude under discussion are difficult to ascribe to faulty connectors or fibre optic cables, in any case these would have easily been detected before such a mistake was observed.

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