Jan 10 2018

Bits And Bytes – Program 9: Computer Graphics

Ah, now we’re getting into one of the more interesting nuances of the 80’s computer scene – graphics! While today our systems simply use software to create everything we see on screen, with hardware doing the raw math to make it all happen, back in those days, you didn’t have processing power, memory, or, well, anything to spare.

In those days, things were quite direct. In most cases, the system was told explicitly what to draw where on the screen based on a built in method that the computer had. For example, Commodore machines, as demonstrated in this episode, had graphics characters alongside normal characters (PETSCII as it’s known) and these could be used to draw simple graphics on Commodore systems. In other methods common to most all computers, colors could be drawn directly on the screen and, depending on limitations of the individual computer, you could get some pretty impressive images generated.

Of course, what you could draw in what method depends on the resolution capabilities of the computer system you were working with, but there were limitations – higher resolution, or more detailed graphics modes, usually lacked as many colors as the lesser modes.

It’s an interesting aside to think that the big issue between “4K” and “HD” TV today is one of resolution. Some things never change…

The first part of this episode goes into some detail on the above topics, starting off on the Commodore PET to demonstrate PETSCII and character graphics, before switching to the Apple II for most of the episode to show off its rather impressive graphics capabilities.

Of course it has the obligatory commentary from members of the computer graphics field, discussing using computers to produce art on one hand, and on the other, the nature of graphics in business – something anyone who has messed with the graphing functions in Microsoft Excel knows quite well, as a modern example.

The tail end of the episode goes into a nice, simple explanation on the differences between a computer monitor and a television set. Back in the 80’s, the more common home computers were connected to your TV set, much like a game console, rather than a dedicated monitor. Yes, you could buy a monitor, but those were expensive, on top of an expensive computer, but they did provide much better image quality and higher resolutions, but for most users a TV set was quite adequate back in those days. Hell, even now some vintage computer users still use TV sets for the sake of historic accuracy.

A fine episode that touches well on concepts that are still very relevant today.


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