I'm a hobbyhist -- and relatively new to microcontrollers -- and I'd like to set up two or more AVR microcontrollers (90S8515s, if it matters) such that they can both read and write to some shared SRAM. I'd like to know to how I should build the circuit so the micros don't interfere with each other (e.g., prevent two of them from writing at the same time, etc.). I'm interested in both typical and low-cost methods (in case they are not the same ;-) ) of designing such a system.
If my question is easily answered in an undergrad textbook, please forgive me. If such is the case, I'd appreciate book suggestions and the relevant topics.
Thank you for your help.