I am trying to design a developer's cart that includes two or four 8-bit EEPROMs and the maximum amount of RAM that the console can access.
![Image](http://i.imgur.com/FAnnHN9l.png)
I really only need to worry about 1 or 2MBytes of ROM, but I would like to find out how to wire up the maximum amount of RAM.
Is the maximum going to be Serial:
![Image](http://imagizer.imageshack.us/v2/640x480q90/199/6rhz.png)
or Parallel:
![Image](http://imagizer.imageshack.us/v2/640x480q90/841/awfs.png)
The cart that I want to make will have all newer parts, so no official carts have to die. Depending on whether parallel or serial can be larger, then I will design the board around that.
For example:
![Image](http://i.imgur.com/pf3uDBRl.png)
Also, if some of you are aware, the parallel SRAM mapping will normally use the /LDSW pin as the /WE. If I am not mistaken, the /LDSW pin is used as an 8-bit port for writing to certain locations. Can the /UDSW also be used to add a second writable bank of RAM? Theoretically?
![Image](http://imagizer.imageshack.us/v2/640x480q90/20/pia2.png)
Thanks all,
Jazz