Composite video at the ZX81 and ZX Spectrum

The orioginal ZX 81 and ZX Spectrum had only a UHF television output that is no longer available on modern televisions and monitor. The ZX Spectrum 128K als had a RGB output that still can be used on moder televisions. But this website demostrated how to make an AV output easily on you ZX 81 and ZX Spectrum.

One problem on the ZX81 is that the image is quite dark. The ZX Spectrum does a better job.

http://mrpjevans.com/2013/04/how-to-zx-spectrum-composite-video/

http://www.jammarcade.net/zx-spectrum-composite-video-mod/

Good all-round explanation

http://samsmods.blogspot.co.uk/2011/10/zx-spectrum-48k-composite-video-mod.html

Zen-like modification that removes the RF modulator

http://www.brianhoskins.co.uk/website/spectrumcompositemod/

Another demonstration of using the capacitor

Pipistrello project for making HDMI output on a ZX Spectrum

http://blog.gadgetfactory.net/2013/07/spectrum-zx-with-hdmi-out-on-the-pipistrello/