Скачать или смотреть PM5644 - Indian Head version

It is probably the most mysterious test pattern generator in existence. Its pattern is the logo for my main channel. It is the Indian Head PM5644.

Was it a catalogue model? Or was it a custom model? If so, for who? We just don't know for sure. Almost no Philips TV & Test Equipment written material from this era has survived. I bought it from a dealer who bought it at auction. There is no way to find out who originally owned it.

It outputs a true monochrome 625 line video signal (PAL, but not really) i.e. no colourburst. A digital reproduction of the pattern exists in various places around the internet. That image originates from this piece of equipment and was created by me using a tool I developed to convert PM5644 PROMs into bitmap images.

The recent open-sourcing of the PT5xxx series by DK-Technologies offers some small (speculative) insights into it. The pattern was probably designed in January 1993, however this unit was clearly assembled in 1996. For this reason I think it is unlikely to be a custom model.

A long and speculative journey later, I think this was something the engineers designed for fun, and also to test out the new features of the software which are all in-use in here. They put it in the catalogue (caveat: a catalogue listing all of the PM5644 versions has never been found) on the off chance that someone might buy it, and eventually (somebody) pulled the trigger, and here it now is. A very interesting piece.