Thanks a lot for the help. Well,this circuit is very simple, I know, but it's only the beginning. I only need to know how to connect peripherals to the CPU. So leds and switches are sufficient! :)
My plans are to use the 80c390 to control a robot...in a (I hope^_^) near future!
I was suspecting that using RD is preferable for stretching acces cycles...now i've got the confirm!Thanks!
I've modifyed the circuit and I hope that now all is ok(please have a look^_^).
In the circuit is missing the rs232 interface because my protel library with rs232 drivers doesn't work...
So, you say that on the reset input is only needed the button + the resistor?
My idea for programming the ram is to put a loader into the CPU and download the programs via serial link.
The problem is to put the loader in the CPU...
My idea is:
-program the sram with a program that loads the loader into the cpu using a simple parallel port programmer wich i've designed.
-run the cpu with this sram and let the program save the loader in the internal NV-SRAM;
But software is the next step. For now i only would like an hardware design that is correct.So, the only errors (and i think tere'll be a lot!;)) can be only in software.If something doesn't work and i'm not sure about the hardware, i go crazy trying to fix the problem.
Thanks again and excuse me for my poor english...(i'm italian).