well I’m only going to go over this quickly as a fast reference. if anyone wants to look any of this up in more detail there are plenty of sites and always Wikipedia.
there are many computer graphics standards but first I’ll go over the most basic ones that will be dealt with in a classic computer setup starting with the first color graphics standard. Originally I took some crappy “point camera at screen and click” pictures but then I decided to hell with it and I just used DOSBOX and screenshots. I’m not a fan of emulation but here it serves its purpose.
Remember that computers began with very limited resources and those limited resources as well as cost kept initial color graphics on the computer limited. Remember that more colors and higher resolution requires more RAM and RAM could be expensive. In 1981 RAM cost $8,800 per Mbyte compared to the end of the DOS era of 1996 at $29.90 per Mbyte of RAM (according to here). I’ve used the game Eye Of The Beholder as a guide to illustrate the differences between the standards.
Hercules Graphics – This popular monochrome standard actually came out after CGA in 1982. It does seem like a set back in the fact it can only display 1 color but CGA cards could not do text very well and the Hercules card was backwards compatible with MDA (the monochrome display adapter) so it was very popular for business. It also had CGA emulation meaning it could take a CGA game and render it in monochrome. It had a theoretical top resolution of 720×350 and also had the ability to display to dual monitors. I could not get Eye of the Beholder to display in Hercules mode so here are screens of Outrun in Herc mode. If your monitor was a green or amber screen then the image would be displayed in that color.
Black and White monochrome
Green phosphor screen monochrome
CGA – Color Graphics Adapter was introduced in 1981. It could display up to 640×200×2 resolution as well as 4 colors at any time from a palette of 16. Two common color schemes were available, Magenta, cyan, white and background color and Red, green, brown/yellow and background color both were pretty hideous.
Also of note is that some CGA graphics cards as well as some computers of the era offered composite ports for hooking up to a TV. Interestingly programmers were able to make some games look better using the composite connection by utilizing the quirks of composite. composite isn’t very sharp and programmers were able to use the fact that it blurs and blends colors thus creating more colors then the standard CGA when hooked up via the composite port. Ultima and burger time are two games that quickly come to mind that had more color when using a composite hook up. The downside of using composite instead of CGA is the picture can sometimes look less sharp and text can look very blurry.
TGA – Tandy Graphics Adapter, actually this graphics mode was originally released with the failed IBM PCjr in 1984 as “CGA Plus” but after the system flopped it became known as the Tandy standard since the Tandy 1000 line of computers were originally PCjr clones. Many games ended up supporting this mode on Tandy 1000 machines and it is very similar to the later EGA standard many times looking identical. It is capable of 640×200×4 resolution and can display 16 colors at once from the available 16 color palette of CGA.
EGA – Enhanced Graphics adapter was also released in 1984 and was capable of higher resolutions and more colors in total. EGA can display up to 640×350 resolutions and even up to 720×540 via later expanded graphics modes. It can display 16 colors at the same time from a palette of 64. the EGA and TGA modes of Eye of the Beholder look identical. EGA is also backwards compatible with CGA
it should be noted that despite the identical nature of the visuals here EGA and TGA can have vastly different looks depending on the game. One well know example is Thaxder.
TGA
EGA
TGA looks to have better color depth and overall color while EGA has a higher resolution and numbers and letters are sharper.
VGA – Video Graphics Array, This is what most of use are used to. VGA was introduced in 1987. It could display a resolution of 640×480×16 or 256 colors in 320x200x256 from a palette of 262,144 colors. VGA is also backwards compatible with CGA and EGA.
MCGA – Multi-Color Graphics Array also released in 1987 was a stripped down VGA standard only used in some low end IBM PS/2 models and some Epson clone machines. Its mostly CGA compatible but NOT EGA compatible. It could do 320×200 in 256 colors like VGA but not some of the higher resolution VGA modes. There were never any add on MCGA cards since VGA was vastly superior for only a little more cost.
SVGA – Super Video Graphics Array came out the same year as VGA. it is essentially an extension of VGA capable of 800×600 resolution and was continuously updated by the VESA or Video Electronics Standard Association. more info can be found on Wikipedia under SVGA. this was really the main video standard from the late 1980’s and up. I currently do not have a comparison screenshot but most times its identical to VGA except for higher resolutions.
keep in mind this is just skimming over the most commonly used graphic displays and is certainly not comprehensive especially in regards to odd or extended resolutions available. I would highly suggest googling or Wikipedia for more information.
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