Displaying characters and graphics on a TV with a Z80 computer.

[Volt]

Hello, my first post! 

I have been building a Z80 computer for the past couple of months and I have hit a bit of a brick wall, the problem is that I want to be able to plug my computer into a TV (PAL, preferably composite). So have been searching for IC's that may do the trick, I have taken a look a the MC6847, MC6845 and 6561 VIC but their a bit complicated for me at the moment.

My main constraint is that I don't want to use a microcontroller (So the Arduino TVout library is ruled out for me), therefor is there a simpler way/IC for printing to a TV screen?

Thanks for reading, hope I have given enough info and sorry for bad grammar/spelling. 

[BulletMagnet83]

http://www.waveguide.se/?article=bitmapped-video-interface

Perhaps this will be useful? I've literally just finished reading it.

[alank2]

This guy is doing it with an AVR, but you might find some good info and ideas:

http://www.batsocks.co.uk/products/Other/TellyMate.htm

[BulletMagnet83]

Actually, thinking about it some more... all the devices you've mentioned are geared up for a 68xx / 65xx type of bus, and rely on shared memory. They might be a pain in the arse to rig up to a Z80 (though possible, you'll need to do some fiddling).

What might be the best option is to get hold of a TMS9918/29 instead. The Sega Master System used a similar and mostly-compatible VDC with a Z80 CPU, and the 9918 & variants use their own separate DRAM-based video memory. It handles all the timings and addressing for you, so no need to worry about the black arts of DRAM.  IIRC, you write to it just like an I/O port, and would need some sort of interrupt setup so that the video memory is only updated during the vertical blanking interval.

Search for a schematic of the master system and you'll get a feel for how it all fits together.

[Volt]

I have been looking at your suggestions, I think the Bitmapped video interface may be the best way at the moment until I can get my hands on a TMS9918, it seems simple to build and program for.

Thanks for your help