Did it with a PIC 18 chip - this provides a 32 or 40x24 PAL mono text display, and a degree of graphics capability through character pattern redefinition (on the fly). Control of the display can be via serial or parallel interface and the whole circuit is based on the PIC chip plus two resistors, two de-coupling capacitors and a crystal.
As the PIC video routines are entirely interrupt driven, only portB outputs and 1 bit of portC used along with TMR0, it's possible to run other applications on the PIC (even written in BASIC if done correctly), and still have perfect video output.
PM me if you are interested and I can send pictures, source and circuits..... (think of a ZX81 on a chip and you won't be far off)!
PS Used Rickards site as a good source of info - well worth a look.....