I've been working on designing a simple game (remember "Combat" on Atari 2600) for my custom system.

I have now something playable at least. So I'm quite ready for my next week-end presentation :)

Last week, I ordered a whole bunch of components, which arrived today. A lot of stuff to play with :

• Lots of passive components.
• Many 74LSxx ICs.
• Some basic PLDs.
• Adapters from SOIC to DIP.

Yeah, after many months spent at playing with programmable logic devices, I want to get "closer to the metal", and build "real things" by myself. With all that stuff, I'll be able to build complete systems, from the power supply to the TV interface. Even if the technologies employed are a bit obsolete, I think it is a necessary step for me, before trying to do things more advanced, like designing a system using surface-mount components, its PCB, and have it build by a company.

Here are the things I plan to do in the upcoming months :

• Learn to program the SX microcontroller. It is very easy to interface, and I think I could use it as a "testbench" for my future designs.
• Build a TV interface using a AD725 chip.
• Interface some microprocessors (Z80, 6502 probably) to make a simple computer. This could lead to hardware emulation of some old 8-bit systems we all know...
• Build another custom CPU, using mostly "hard-wired" logic instead of programmable logic.

Ok, I have received the XGS Pico Edition kit, and read most of Andre Lamothe's eBook (see XGameStation Website for more information). Interesting stuff indeed. I quickly built the small system, and as I have no NTSC-compatible TV, I just ran the "blinking led" example. The whole thing on the breadboard isn't very comfortable to deal with, though.

The idea of using one of these Ubicom hi-speed microcontrollers to make a GPU seems very good, but after reading all the stuff about composite video output, I think I won't use it the same way it is done in the XGS System. I will probably use some PAL enconding chip (MC1377 is one possibility, AD725 is a more recent one, and I have samples of it on their way...).
Last possibility I just thought of : use the SCART interface available at least on most TVs in France. Funny thing about SCART : it is a french acronym, but totally unused in France, where it is called "Péritel" :)