This is a derivative of QUAD by Steve Adolph.
Removed the resistor-cap power-on-reset. The bank-selection logic is powered at all times by VMEM along with the ram.
New PCB design.
PCB from OSHPark or PCBWAY
BOM
Note for PCBWAY: On the PCBWAY order form, change "Min Track/Spacing:" to "6/6mil"
Initially that setting will say 4/4mil and the price will be over $50.
All tracks and spaces are well over 6 mils, so change "Min Track/Spacing:" to "6/6mil" and the price drops to $5
Use the software & directions for the original QUAD
Note, this version of the device will select an unpredictable random bank on the first power-on after installing.
Don't assume you are in bank #0 until after you use either the simple bank-switch program or 0QUAD to explicitly switch to a bank the first time.
Steve Adolph for sharing his original design and allowing this derivative.