Installing the world’s worst video card

erek

Supreme [H]ardness
Joined
Dec 19, 2005
Messages
6,951
"In these videos, I talk about how VGA signals work and build a circuit that provides the correct timing of sync signals so that a monitor recognizes the signal and displays an image stored on an EEPROM."

 

GiGaBiTe

[H]ard|Gawd
Joined
Apr 26, 2013
Messages
1,365
I'm not sure what that is, but it doesn't look like an S3 ViRGE 3d decelerator card to me.

It's the most basic of video signal generators.

The 74xx logic chips generate the horizontal and vertical sync and counters keep track of where the electron beam currently is on the display (or in this case, which pixel on the LCD screen.) Memory is read in a linear block by the video circuitry and displayed pixel by pixel on the screen. In this video, Ben changes the video circuitry from reading a static ROM to reading RAM that a 6502 CPU controls. There's some additional interface logic, like bus buffers to act as arbitration to prevent the video circuitry and the 6502 from accessing memory at the same time.

What you see here is basically what the video circuitry of early home computers was like, such as the TRS-80 or Commodore PET.
 

pizzathehutt

Weaksauce
Joined
Mar 23, 2007
Messages
69
I'm not sure what that is, but it doesn't look like an S3 ViRGE 3d decelerator card to me.
As a former owner of a Diamond Stealth 2000 S3 virge 3d accelerator card, i can confirm that was indeed the worlds worst 3d card,....but if you turned off the 3d and loaded Descent with glide.....mmmmmmmm.
 
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