I left school at 16 year of age. I knew two things, I didn't want to stay at school and do A-levels and I was good at most sciences, particularly astronomy. So I started studying physics, whilst working on marine radar, but slowly I started specialising in electronics, which has now been my profession for over 30 years: for the majority of this time I have specialised in video. Having been employed for so long in this field, I rather felt I wasn't doing it justice to not have a page on my website dedicated to it. So here it is.

If you wish to contact me then please e-mail me at daniel@danploy.com.

The page was last updated on 7th April 2009 .

Fifteen Minutes of Fame

I have had a paper accepted for a poster session of the ICCE conference in Las Vegas. You can read a draft of the paper submission here.

Dragons

This marvellous article from the BBC, in celebration of the 25th anniversary of the Sinclair Spectrum computer certainly brought back memories. I remember attending a seminar on the Motorola 6800 microprocessor. I was bemused and excited at the end of it, the potential of these devices clear to all. I bought a NASCOM home computer based on the Z80 microprocessor. It was not long and I was designing add on peripherals and coding in assembler. I bought a Spectrum computer for my father's Christmas present and quite often, when I visited, I would see him using it to play word games such as Scrabble. I bought a Dragon 32 computer as I was a fan of the Motorola microprocessors and it has a 6809 at its core. It has an expansion port which I used to develope further hardware, and I later used to in my own company as the development computer; every design would have a 6809 processor at its core. The Dragon had a 6809 assembler, but could run OS-9 and Forth; it was a serious machine. I my mind is easily outperformed the BBC micro and was a more 'serious' machine than the Spectrum because of its choice of microprocessor. Like quite a few innovative designs it died of course, but I was pleased to find a few enthusiasts are still trying keep the thing alive. I later used the 68008, an 8-bit version of the 68000 microprocessor, in my work, but today of course the ubiquitous PC is used for all development. But nothing can replace the excitement of using and working with those early microprocessors.

Audio Amplifiers

I went through a phase of building a number of audio amplifiers. For preamplifiers I built the designs of Douglas Self as published in Wireless World. You can find these articles in his book, Self on Audio. I built my own PCBs and I thought they sounded really great, but the real letdown was my mechanical ability in putting them into some reasonably decent box. I wish I still had them now though. For power amplifiers I started by using the hybrid modules offered by Sir Clive Sinclair's company, Super IC-12. A friend had introduced me to these amplifiers and he had the complete kit, System 60. He was also much better at building boxes than I was. I did build my own power amplifier, I can't remember where the design came from now, but I also happened across a Leak valve power amplifier, which produced great sound: I wish I had held onto that. I was pleased to find some articles on the amplifier on the Internet, Leak 20 amplifier. I noticed there is one available on e-Bay, I am tempted to place a bid. There is certainly something aesthetically pleasing about it and it would look good with the valve magic eye indicators as well. Now I just need to get some PCBs done for one Douglas Self's pre-amplifiers and I will be where I was twenty years ago! It will certainly be fun doing it though.

FPGAs

When I started out as an an engineer, programmable logic arrays were in their infancy. My favourite was AMD's 22V10, which offered an amazing 10 programmable flip flops: I used them mostly for counters and shift registers. Now, of course, some huge devices are available, capable of integrating entire systems. Of the two main companies in this field I have always been and Altera man, now down to familiarity with the tools, but intially because the compile tools were so much faster and friendlier. For those who are serious about designing using FPGAs, this platform offers a great way in; it's list price is about $1095, but usually there are some special offers for about half of this, and it comes with all the software.

However there are no analogue inputs or outputs. To this end I have designed a piggyback board that plugs into the Santa Cruz connectors on the board. Details of the board can be found here, DP1 user manual (requires Adobe Acrobat Reader). Over the next few days I will post more details and the PCB, the overlays, and the complete board will be made available for sale.

DP1 accepts analogue video, either standard or high defintion, which it filters and buffers using a Analog Devices ADA4411 IC, before clamping and converting to digital video using Analog Devices AD9981 triple ADC device. The input video can be composite (although decoding must be done in the FPGA), B/W video, or YPbPr or RGB format. The ADCs can operate up to 80MHz sample rate and provide 10-bit output data for the FPGA. In addition the synchronizing signals are stripped off the incoming composite sync and are filtered to provide hroizontal and vertical timing information to the FPGA. A programmable line locked clock is also provided. Control of this IC is via the I2C bus. On the video output side, digital video is output from the FPGA to an Analog Devices ADV7321 video digital to analog converter/video encoder IC. The digital video can be converted to analogue YPbPr or RGB signals using 12 bit DACs at standard or high definition. In addition the IC can also encode the video to either PAL or NTSC composite standards. The outputs are filtered and buffered using an Analog Devices ADA4412 IC. Again the IC is controlled via the I2C bus, and a number of filters are available internally. The video ADC and DAC run independently so it possible to up-convert, timebase correct or re-synchronize the video between the input and output. To aid development a 27MHz oscillator is also provided which drives one of the PLLs on the FPGA. An Analog Devices ADAU1326 audio codec is used for the audio channels. Stereo analog audio is converted using 24bit ADCs at either 44.1, 48, or 96kHz. The output I2S formatted data is sent to the FPGA. I2S data from the FPGA is then sent to the audio DAC where is is converted back to analogue using 24 bit DACs. Again this IC is controlled using I2C bus. The board plugs into the two Santa Cruz connectors that are provided on both of the NIOS development board and derives all the power supplies it requires on board from the raw supplies provided on those boards.

Curiouser and Curiouser

As an older engineer I was lucky enough to work with, or least see in operation, some of the more esoteric electronic devices that have ever been created. Whilst I was working in Singapore I mentioned, slightly sarcastically, that to get our product noticed we should use a mercury arc rectifier. I was disappointed to find that no-one knew what one of the creatures was. Well if anyone is also curious, this website tells you all you need to know, http://www.tigercom.dsl.pipex.com/, and I have borrowed one of their images to wet your appetite. I saw one of these in my first job as an radar technician, and spectacular it was too; I would watch it for hours. There are also some excellent photographs and information on this website, http://www.electricstuff.co.uk/mercarc.html. It is where I got the photograph on the right.

When I was young my parents bought me a reel to reel tape recorder. I didn’t have much time for the constant hissing of cassette recorders, these were early days for Dolby and I never liked the idea of compression much, and these machines were a marvel of mechanical engineering. A number of the functions were still performed by valves, and one in particular was the valve recording level meter, or magic eye. This website explains more about these remarkable devices, http://koti.mbnet.fi/siliconf/JukkaTolonen/ga/peakmtr/peakmtr.html. They were eventually replaced by more precise meters or worse rather course LED arrays: a great shame in my opinion.

I was lucky enough to be able to accompany the atmospheric physics group of Southampton University to northern Sweden, Norway and Finland to observe the aurorae borealis. I was responsible for operating a 4inch intensified image isocon all sky TV camera which observed the aurorae. There is some more information on a similar group here, http://alomar.rocketrange.no/allsky-video.html, including some fantastic images of the aurorae. This site also has some mesmeric images of the aurorae, http://www.ptialaska.net/%7Ehutch/aurora.html#Latest%20Images.

In the Beginning

In 1984 I wrote a series of articles for the, now obsolete, Electronics Today International magazine, on the construction of a high performance video framestore. These products were generally restricted to the broadcast TV and other very specialised areas of application and were not thought to be the domain of 'amateur' electronics at this time; as is mentioned in the article, a single component, the video analogue to digital converter, cost over 100 pounds to buy, and the product used 64 dynamic memory ICs, which were not as cheap and commonplace as they are now. None-the-less the article still has some interest. You can read it here, (Adobe Acrobat reader required).

Two years later I followed up those articles with a lower cost, but inevitably lower performance, version. The editor chose to put this construction article on the front page and it brought in a lot of publicity for my own company, which I was then running. Click on the front page to bring up the full article.

Awards

One achievement of which I am particularly proud, is receiving the Senior Membership of the IEEE, the foremost electronic engineering institute in the world. This accolade is reserved for less than 10% of the membership, and we receive a small commemorative plaque.

In my opinion the IEEE is leagues ahead of any other electronics institute. It literature and influence is excellent and substantial. To find out more about the institute please follow this link, http://www.ieee.org/portal/site.

The Writing Bug

The two page article on the left, also from 1986, describes some of the applications that were then starting to appear for video processors and video framestores. Click on the page to bring up the full article.

The second article was commissioned by ETI. A number of readers has asked how to convert RGB into composite video so it could be viewed on a normal TV, for example for use with the BBC computer which was then popular. Thankfully video was a black art then, indeed little has changed, so the editor called me and asked if I would be willing to design something. The article is a result of this.