* Posts by drgeoff

32 publicly visible posts • joined 13 Mar 2013

How Sinclair's QL computer outshined Apple's Macintosh against all odds

drgeoff

Re: Love/Hate

It was videotape, not audio cassette tape.

ZX Spectrum, the 8-bit home computer that turned Europe on to PCs, is 40

drgeoff

The Texas Instruments chips had 64Kbit dies inside but the packaged chips were labelled as 32Kbit parts and sold as such. The part number indicated which half was good. All 8 of them in any one machine had to have the same good half. There was provision on the plug-in daughterboard in early versions or on the later single PCBs to select which type was fitted.

ASUS recalls motherboards that flame out thanks to backwards capacitors

drgeoff

Re: It was fun when I saw that happen

Difficult to do anything exciting with 12 Volts and a lot of electrolytics in _series_.

Developer creates ‘Quite OK Image Format’ – but it performs better than just OK

drgeoff

Re: Colour me impressed...

Blu-Ray does not use lossless compression. For example the uncompressed rate of 1920x1080x25 interlaced 8 bit luminance is 51.84 Mbyte/s. Add on the same again for the two colour differences each 2:1 subsampled and you are over 103 Mbyte/s. That is 825 Mbit/s. Far in excess of 20-30 Mbit/s.

It may come close to "visually lossless" but what comes out of the decoder is not exactly the same as what went into the encoder. But pretty good going when you consider the compression ratio.

The web was done right the first time. An ancient 3D banana shows Microsoft does a lot right, too

drgeoff

Re: Maybe Windows 3.1 was a sweet spot?

I'm still using Paint Shop Pro 5.03 on Windows 10.

Third time's a harm? Microsoft tries to get twice-rejected encoding patent past skeptical examiners

drgeoff

Re: Nope

" ....point to prior art and if it's clearly a non inventive patent that is already seen in the prior art .."

In which case the patent should never have been granted.

Watt's next for batteries? It'll be more of the same, not longer life, because physics and chemistry are hard

drgeoff

Re: Thin films, thin arguments

@steelpillow

What are you prattling on about? Neither Sony's nor any other magnetic tape has ever been lithium based.

CrO2 and Fe stood for Chromium dioxide and Ferric (ie iron) respectively.

Apple's M1: the fastest and bestest ever silicon = revolution? Nah, there's far more interesting stuff happening in tech that matters to everyone

drgeoff

Re: Headline-whoring

The 6502 was from MOS Technology. Motorola's offering was the 6800.

Did I or did I not ask you to double-check that the socket was on? Now I've driven 15 miles, what have we found?

drgeoff

Re: Why are sockets switched?

To make tea properly you must use freshly boiled water. Not water that has had the essential oxygen reduced/removed by previous heating.

TomTom bill bomb: Why am I being charged for infotainment? I sold my car last year, rages Reg reader

drgeoff

Re: TomTom ....

Surely you meant "out of date 6 months BEFORE you purchased them".

One does not simply repurpose an entire internet constellation for sat-nav, but UK might have a go anyway

drgeoff

Re: These satellites have high precision atomic clocks on board?

"I recall (perhaps in error) that the receiver chip is hard coded to know where the satellites are (constellation in the sky)".

No perhaps. You are in error. Put "almanac data" into your chosen search engine.

Faxing hell: The cops say they would very much like us to stop calling them all the time

drgeoff

Re: My first modem..

Fax is still very much alive in Japan. That's why the All-in-One printers from Epson, Brother, Canon etc have it.

Built to last: Time to dispose of the disposable, unrepairable brick

drgeoff

Re: It's not just Laptops and Smartphones

Service manuals were prepared for use by service departments, not end-users. But the economics of mass production versus the cost of skilled repair technicians means it is now cheaper to give the customer a new replacement that run a service department that actually repairs things. Similarly for out of warranty items - a new item can often be purchased for less than what a service department would need to charge to cover its running costs. Hence service departments that actually repair things disappear, and the need for service manuals (which if any good are expensive to produce) disappear too.

A user's magnetic charm makes for a special call-out for our hapless hero

drgeoff

Re: Hmmmm shadow masks

https://en.wikipedia.org/wiki/Beam-index_tube

drgeoff

Re: Hmmmm

Sony's early PAL TVs used the modulated chrominance signal from only every alternate (in time) line. The gaps were filled by repetition using a glass delay line so that the following demodulation stages saw a signal with no line by line inversion of the phase of the V component. In effect the PAL signal was converted into an NTSC like signal.

drgeoff

Re: Hmmmm

My parents' first TV was a Decca DM4C 17 inch purchased in the late 1950s. (I remember seeing the very first episode of Coronation Street on it.) One Easter my father decided to take it with us when we went to spend the break with my grandparents some 60 miles away who did not have a TV. No picture could be obtained. Sound was OK but not a hint of anything lighting up the screen.

Back home and with a still dead screen the local TV repairman was called in. Back in those days the electron gun was deliberately angled such that it did not fire directly along the axis of the tube. An "ion trap" thing was clamped round the neck near the heater. Shaped like an omega clip, two curved pieces of metal with a permanent magnet between one pair of their ends and a nut and bolt at the other ends. Adjusted in the factory to bend the electron beam so that it went through the centre of the deflection coils but the heavier ions did not. With the hour and a half of vibration during the car journey the thing had become loose and the weight of the magnet had tuned the assembly sufficiently out of position that no electrons at all were getting forward to the deflection coil area and thence to the phosphor screen.

Go fourth and multi-Pi: Raspberry Pi 4 lands today with quad 1.5GHz Arm Cortex-A72 CPU cores, up to 4GB RAM...

drgeoff

Re: Sata

I fear that Nick Ryan is confusing "a USB3 port may carry video" with "a USB3 port shall carry video".

drgeoff

Re: Sata

So why hasn't anyone produced a SATA interface addon board to attach to that parallel expansion bus?

Because it is a figment of Marco van de Voort's imagination.

Mobile networks are killing Wi-Fi for speed around the world

drgeoff

I'm a tight bar steward and don't give a monkey's if the free Wi-Fi my phone is connecting to is slower than the metered 3/4/5G network which I have to pay for.

A volt out of the blue: Phone batteries reveal what you typed and read

drgeoff

Re: chars

There are several capacitors between the instantaneously changing power draw circuity and the battery. Those smooth out the rapid variations in power draw. Furthermore the OS is not sitting doing nothing - lots of things are happening in the background making their own changes to the current consumption. Those are merged with any changes from the character drawing circuitry and the resultant total variation smoothed by the capacitors.

I very much doubt that any measuring device in the battery could tell what characters are being typed.

Europe is living in the past (by nearly six minutes) thanks to Serbia and Kosovo

drgeoff

Re: 240/230/220V

Another urban myth. There was no change to the actual voltage. http://coffeetime.wikidot.com/uk-eu-mains-voltage-harmonisation

drgeoff

Re: Power frequency off??

There are more places inthe world than the USA. All of Europe, half of Japan and many other places use 50 Hz.

And to correct another poster, Japan is 100 volts not 110.

Raspberry Pi burning up? Microsoft's recipe can save it and AI

drgeoff

No sandwich

RPi3 (and RPi2) do not have the "club sandwich". The Broadcom CPU + GPU chip and the RAM chip are on opposite sides of the PCB.

Windows 10 Anniversary Update: This design needs a dictator

drgeoff

Windows 10 does NOT run on a RaspberryPi. Windows 10 IoT does, but that is a completely different kettle of fish.

An on-demand video subscription isn't just for Christmas... Oh. It is

drgeoff

Re: Over The Top

"It's supposed to indicate that it's supplementary to normal Over The Air (OTA) broadcast."

Wrong!

As Wikipedia says:

"In broadcasting, over-the-top content (OTT) refers to delivery of audio, video, and other media over the Internet without the involvement of a multiple-system operator in the control or distribution of the content."

WORLD CUP TRAUMA? Just Streaming Stick a Roku in it

drgeoff

Re: Now TV hack closed now

Cobblers. Developer mode is still available with the latest (5.4) firmware for the NOW TV box. I've enabled developer mode and sideloaded PLEX and Mediabrowser (not simultaneously) since getting the 5.4 firmware a few days ago.

Infinite loop: the Sinclair ZX Microdrive story

drgeoff

Microdrives never contained EPROMs (or ROMs).

The article incorrectly states that the first 1000 or so microdrives had EPROMs. They only had one IC in them and it wasn't a ROM or EPROM. The Interface 1 had a ROM (8 Kbyte?) and I have previously heard that early units had EPROMs rather than masked ROMs.

drgeoff

Re: Sinclair, what was that all about ?

The chip with the armadillo heatsink was the Sinclair Super IC12 power amp. It was actually a remarked Texas Instruments device. I soldered all 5 of mine into matching PCBs also supplied by Sinclair. I cannot recall if the PCBs were an extra purchase or bundled with the chip.

The earlier IC10 audio power amp, with metal heatsink bar running through it, was a rebadged Plessey device.