It doesn't take a Rocket Scientist to work out that this is not going to work. I'm already at the full board size Eagle support for the free version and I don't have any room for routing traces.
I need to re-think this. My options are:
- Abandon the switch and RAMDAC and have the GPU to it all.
- Come up with a better switch.
- Use dual-port SRAM.
The second option could be solved with something like a FPGA of CPLD. I need to look into the cost of these. An initial look reveals this one has 120 GPIO pins and is $31. The other cool thing about an FPGA is that I could move the CLEAR SCREEN command to the FPGA and free up the GPU too.
The third option appears infeasible at this point. I can find dual-port SRAM at good price. That said, I could de-solder some from an old video card. Hmmm, might look into this. This is the ultimate because it means I can put the GPU and RAMDAC on opposite side of a single RAM IC. This is likely to be a dead end though as I'm pretty sure all most video cards use a derivative of DRAM, and I'm not getting into that.