Here's one guys attempt at a digital Philips generator (PM5544).

http://homepages.ihug.com.au/~daz2002/tech/TP/index.html

If you're familiar with the Philips generators, the patterns are all analogically developed. The chips are all soldered in. Digital would clearly be the way to go.
The Tektronix generator I have (TSG170A) the patterns are read out of proms.

I just take a digital image of the Philips pattern from the web and play it on a digital media player capable of handling still images.