Post by thread:[EE]: A Low Cost Analog and Digital TV (DVB-T) Mod

Alex Harford wrote: > (Resent with tag) > > http://fabrice.bellard.free.fr/dvbt/ > > Clever idea, using a video card's PLL to transmit in the VHF band. > VERY cool! I knew Tempest for Eliza, but not this one. -- Hector Martin (spam_OUThectorTakeThisOuTmarcansoft.com) Public Key: http://www.marcansoft.com/hector.asc

Its just DDS (Direct Digital Synthesis) using the fast DACs on modern video cards with the timing adjusted to meet DVB standards, and relying on high harmonic content of the output to reach the desired RF channel frequency. Using a PC video card to output arbitrary waveforms is NOTHING new. I did it back in the late 1980's when all we had was EGA. Back then the CRTC (MC6845) commonly used was directly programmable. Today it's a lot trickier since you can't directly access all the timing registers (most chip docs are now NDA). Although this project is nicely done. Robert Hector Martin wrote: > Alex Harford wrote: > >>http://fabrice.bellard.free.fr/dvbt/ >> >>Clever idea, using a video card's PLL to transmit in the VHF band. > VERY cool! I knew Tempest for Eliza, but not this one.