| ??? 08/31/04 18:19 Read: times |
#76693 - RE: Video output with 8052? Responding to: ???'s previous message |
Technically it is possible to generate video signals displayable on TV or VGA monitors. But the practical bottleneck is the speed of 8052 micros. You will need around 10-20MIPS processing for a fair resolution and color depth. 12-cycle derivatives are of no use here maybe 1-cycle cygnal or 2-cycle philips can suffice the need. Here is a link to web-page describing a simillar project & also details the video internals. Excellent links, Prahlad. Reading the second link completely took away the mystery of how TV signals are structured. Thanks! I agree that it would need to be a high speed 8052. But it looks like for B&W the resolution all we need is 52us per scan line so a 160 pixel screen width resolution would require a capability of at least 52us/160 = .325us per pixel, or about 3 million pixels per second. That's doable with a high-speed 8052. I wouldn't even mind seeing a 320x160 resolution which would be 6 million pixels per second and, assuming 8-bit resolution, could store the video memory in 51k of XRAM. So I guess one option is to have a high-speed 8052 dedicated to handling the video output. That'd be cool in the sense that the entire system would be 8052 based. The disadvantage is that it's relatively low resolution and black & white. The other option is having some external video (CGA/VGA?) handle the video. The advantage is that the computer would be capable of higher resolution and color. The disadvantage is that it would no longer be entirely 8052 based. Thanks again for the links, Prahlad. Excellent! Regards, Craig Steiner |
