Now that we all know what Erik does NOT make (guys, he definetly does not make toys!!!), I guess what does he make...
;-)

I agree with you, Erik, anyway: this tecnique of using a single clock source for two micros is not good. Usually I do not make toys, too (although some toys are very technological), but I was UPGRADING an old project with two micro placed ad a few mm each other on the same PCB and that unfortunately used the same clock source.

Maybe this technique is not the best of the world, but it worked with the AT89S53, AT89S8252, and maybe it works with any other 8051, but it does not work with AT89S8253.

That's all, I just wanted to let you know that.

BTW, also using TF2 to generate a software interrupt is not exactly the right way to use it... I know.