6502.org

Hi Greg,

Have you considered using both sides of the board to mount components? I know thats not typical but it might save you some space.

Daryl

> If I am to demultiplex any bank address of the 65C816, a 65C22 or the
> parallel interface dual UART will have to be deleted which will free up
> an address select line and an interupt line from the cpld.

You weren't talking about adding any memory when using the '816, so there's no need to latch, decode, or use the high 8 bits of address. You can still get huge benefits from the '816 even if you only use bank 0 (the first 64KB). So I don't see that you have any problem at all.

Hi Daryl,

Yes I have considered the back side. All caps and resistors (smd) are located on the back. I'm using standard routing techniques. There is really not enough room unless I start from scratch on the art work. Things are so tight now that my minumim land width and spacing is six mils which knocks out a lot of board manufactures.

Garth,
You are right. I'm just checking all possibilities. Well to be truthful, I'm afraid to move away from what I know. That's why I'm not using the 65C816 out right.

I know this is not very practical, but have you considered using another CAD program. ExpressPCB.com offers schematic and board layout software for free, although it does not autoroute and you have to use their service to make the boards.

Please contact me via email for further alternatives.

Daryl
65c02@softcom.net

Hi Garth,

I am putting this project of mine on hold an may start from scratch.
It looks like even a physical 65C816 board design would be more simple and require fewer parts. I will let you know what I come up with.

Greg