The remaining tasks are:
- Finish routing the connections between the circuit blocks.
- Define the inter-board connector pin-out.
- Route the inter-board connector.
- Add some bypass capacitors between the VDD and GND planes
I'm tired of posting screenshots that don't look any different that the previous picture. I considered posting that picture of a bunny with a pancake on his head, but it's been overdone. I just stumbled on a pic of the single bit DRAM cell on a breadboard, so I decided to post that:
This was when I was still trying to figure out how important the "bootstrap loads" were to the operation of the system. Rather than using lower-value passive resistors for this, I was considering using PNP transistors in a current mirror configuration; the three TO-92 components in the upper right of the breadboard are two active loads and the current reference. Also note that all the MOSFETs are BSS83s, as this predated my experiments with the FDV301s.