[GTALUG] CRT memories [was Re: IBM - cache skirmish story.]

Lennart Sorensen lsorense at csclub.uwaterloo.ca
Tue Apr 24 14:49:47 EDT 2018

On Tue, Apr 24, 2018 at 01:33:11PM -0400, D. Hugh Redelmeier via talk wrote:
> Eventually RAM became cheap enough that a colour frame buffer was
> affordable for individuals.  For example, The Atari ST (1985)
> supported only 16 colours at a time for a resolution of 320x200 --
> somewhat usable.  I preferred mine in monochrome at 640x400 but my
> kids preferred colour.

The amiga cheated and could do 4096 colours at that resolution using
about the same amount of ram.

> Now GPU cards come with 4G or more of RAM!

I remember the video card we had in the first x86 my dad has for a
CAD system.  It had 2MB VRAM and 1MB DRAM and a TI 34020 processor
(The TIGA architecture).  It worked using displaylists for the most part
which meant that even though it was on an ISA bus it was able to operate
amazingly fast.  CAD simply sent commands to update the display list and
draw specific parts of the list at specific zoom levels.  Windows 3.1
was also impressive since all the GDI commands were simply sent to the
card to be done there, and moving a window was a copy command sent to
the card followed by the appropriate fill of the leftovers.  Of course
eventually VLB came along and people started wanting multimedia support
with playing videos which it was not suitable for.

Of course Direct 3D and OpenGL to some extent are also display lists,
not counting the transfer of texture bitmaps.  Some things are just so
efficient they are worth using.

Len Sorensen

More information about the talk mailing list