Hey guys

my project requires me to write some characters onto a vga screen using VHDL code implemented on a spartan 2 fpga board. I have managed to get a sample code to display colours on the screen but i have no idea how to start writing characters? any help would be grately appreciated or links or anything.

also if anybody knows how to then update this information depending on button presses/switch changes then this info would also be really helpful.

cheers

A nice and simple example is in book called Embedded Core Design with FPGAs, by doctor Navabi. It consists of a pixel generator, a 60x80 character buffer and a lookup table which contains actual character representations. No DACs, no CPU interface. Source code and testbench is on CD that comes with the book.

Are you just looking for free working IP or do you intend to actually understand the video generation process?
Start by understanding the VGA frame structure and timing. VGA is an analog video standard, and is defined by the timing of the video frame.
If you have a working circuit that generates color bars then you can study the pixel clock and see how many pixels are generated with a given RGB color.
Once you understand how to generate single pixels you can assemble a rasterizer to send rows of pixels in each horizontal display line.
That is how characters are generated in a video display frame, by rasterizing the pixels from top to bottom of the frame.
A purely text display can be created from a text page memory and the raster lines can be generated using a lookup table for each character, using for example the ASCII code for the chars, which is how the original VGA text modes were generated.

Pong P. Chu also has an example in his book FPGA Prototyping by VHDL Examples.

Although it usually seems to me that as soon as you need an interactive character display it makes sense to have a CPU.