Posted October 05, 2014
envisaged0ne: Thank you very much Patryn for your post! I was hoping someone else would chime in on this subject :)
Also, for anyone that wants to see what games used sci0 (ega), sci1 (ega & vga), and sci2, and what each interpreter offered, here is a nice list from ScummVM. The list can give you a bit of interesting history as to how the games advanced through the years
http://wiki.scummvm.org/index.php/Sierra_Game_Versions#SCI_Games
Envisaged One is right... Also, for anyone that wants to see what games used sci0 (ega), sci1 (ega & vga), and sci2, and what each interpreter offered, here is a nice list from ScummVM. The list can give you a bit of interesting history as to how the games advanced through the years
http://wiki.scummvm.org/index.php/Sierra_Game_Versions#SCI_Games
Having grown up with the evolution of these graphics modes it is quite shocking to see so many confused--actually, the superior graphics box of the day was the Amiga--with its 32-color-up-to-4.096 on-screen color modes....that made EGA and early VGA look pretty bad by comparison. BUT...to get back on topic...ahem...;)
The biggest difference between CGA/EGA/VGA at that time was the number of onscreen colors that could be displayed on screen simultaneously--each mode had a total number of colors (called a palette) out of which the on-screen colors were chosen. CGA=4 colors on screen (awful, even then...;)); EGA=16 colors (much better than CGA, but inferior to Amiga displays) and of course VGA=256 colors on screen (all of these were followed by SVGA, then 16-bit color, then 24-bit color then "32-bit" color--24-bits & alpha channel, and so on.)
CGA & EGA & VGA were not incompatible with each other--they were progressive steps along the same basic IBM graphics development path at the time. A CGA game with 4 colors could easily be ported to EGA and still show only 4 colors on screen; a 16-color EGA game could easily be ported to VGA but still display only 16-colors on screen--and it would still be VGA in every respect. There were differences between these modes in screen resolutions, too--but they, too, were easily up-ported to the next graphics mode in the progression.
Speaking of the Amiga, just to illustrate, there were actually many 16-color EGA games ported to the Amiga's 32-bit color mode--but still displaying only 16-bit colors! A long time ago, that used to upset me a lot...;)
Even today, with my "32-bit" graphics card I am running EGA 16-color & 256-color (8-bit) S/VGA games in Dosbox-svn inside Windows 8.1x64 (and now in Windows 10), which are displayed in their original EGA & VGA formats--and that's because my graphics card is still backwards compatible with S/VGA--which can itself run all of those earlier graphics modes with 4/16/ or 256 colors, because S/VGA is itself backwards-compatible with CGA/EGA/VGA, etc.
To sum up, there is almost no difference at all between a 16-color EGA mode game, and the same game running under a 256-color VGA GPU *unless* the game itself has been rewritten to use more than its original 16 colors! If an EGA game is simply a straight port to VGA then it, too, will display 16 colors and be no different in display from the same game running in EGA on an EGA-only graphics device. Both the EGA and the VGA versions, in that case, are running in 16-colors, and the VGA port of the EGA game can also run in the same resolution *if* that is way the port is written.
A *real* S/VGA game--not simply a port up of an earlier graphics mode--would display at least 256 different colors on screen simultaneously. In actuality, there's not a spit's worth of difference between a 16-color EGA game running in EGA mode and the *same game* running in 16-colors in VGA mode. If no other changes were made to the original game other than porting it up to VGA, an observer would be hard-pressed to tell the difference between them.