Video: DOS Gaming Aspect Ratio – 320×200


Occasionally, talks about broadcast topics can be a little dry. Not this one which discusses aspect ratios. For those who feel they are too well versed in 16:9, 4:3 and the many other standard aspect ratios in use in the film and broadcast industries, looking at them through the lens of retro computer gaming will be a breath of fresh air. For those who are new to anything that’s not widescreen 16:9 this is a great intro to a topic of fundamental importance for anyone dealing with video.

This video is no surprise coming from YouTube channel Displaced Gamers who have previously been on The Broadcast Knowledge talking about 525-Line Analog Video and Analog Luma – A History and Explanation of Video. After a brief intro, we quickly start looking at what standard resolutions are today and their aspect ratios.

The aspect ratio of a video is a way of describing how wide it is compared to its height. This can be done by an actual ratio of width:height or displayed more mathematically as a decimal such as 1.778 in the case of 16:9 widescreen. The video discusses how old CRTs display video, their use of analogue dials that changed the width and height of the image.

In today’s world, pixels tend to be square so those encountering any pixels which aren’t square tend to work in archiving and preservation. But the reality today is that with so many second screen devices, there are all sorts of resolutions and a variety of aspect ratios. As people working in media and entertainment, we have to understand the impact on the size and shape of the video when displaying it on different screens. This video shows the impacts vividly using figurines from Doom and comparing them with the in-game graphics from Doom before then looking at aspect ratios across the SNES, Amiga, Atari ST as well as IBM DOS.

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Speaker

Chris Kennedy Chris Kennedy
Displaced Gamers, YouTube Channel

Video: What is 525-Line Analog Video?

With an enjoyable retro feel, this accessible video on understanding how analogue video works is useful for those who have to work with SDI rasters, interlaced video, black and burst, subtitles and more. It’ll remind those of us who once knew, a few things since forgotten and is an enjoyable primer on the topic for anyone coming in fresh.

Displaced Gamers is a YouTube channel and their focus on video games is an enjoyable addition to this video which starts by explaining why analogue 525-line video is the same as 480i. Using a slow-motion video of a CRT (Cathode Ray Tube) TV, the video explains the interlacing technique and why consoles/computers would often use 240p.

We then move on to timing looking at the time spent drawing a line of video, 52.7 microseconds, and the need for horizontal and vertical blanking. Blanking periods, the video explains are there to cover the time that the CRT TV would spend moving the electron beam from one side of the TV to the other. As this was achieved by electromagnets, while these were changing their magnetic level, and hence the position of the beam, the beam would need to be turned off – blanked.

The importance of these housekeeping manoeuvres for older computers was that this was time they could use to perform calculations, free from the task of writing data in to the video buffer. But this was not just useful for computers, broadcasters could use some of the blanking to insert data – and they still do. We see in this video a VHS video played with the blanking clearly visible and the data lines flashing away.

For those who work with this technology still, for those who like history, for those who are intellectually curious and for those who like reminiscing, this is an enjoyable video and ideal for sharing with colleagues.

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Speaker

Chris Kennedy Chris Kennedy
Displaced Gamers,YouTube Channel