Ethan, I can remember (several years ago) my first 6809 kit (bus-based) that had a 512x256 pixel-addressable graphics option. That Euro board was TTL and one littlr PROM for RAS/CAS generation. Originally it had 4116 on them, but 3 power voltages with requirements in the order how they came up (and went away) from the 4116's made me change the 4116 into 4164's. 3-quarter of all the 4164's is not used, but they are single +5V. Works perfect, but I can't remember what I did with the two old 4116 power supply pins. AFAIK is is obvious when you compare the pin of both, at least it was t me at that time. Ah yes, there was also one extra "address" pin, IIRC. Tie that to GND or +5, or put a switch (or software controlled output pin to it) There is your basic "bank-switching"! success, - Henk, PA8PDP.