SCIDYNE :: XMEM+ / 100-7699 512K Expansion Memory for Arduino MEGA and Compatibles
Raspberry Pi to Arduino UNO Compatible Connector Board - RAM Electronics
Arduino Uno R3 & Raspberry Pi 4 Model B 4Gb Ram Other from Vellore
Expanding Arduino UNO memory with 32kB static RAM chip - MCbx
HT16K33 RAM Mapping 16x8 LED Controller Driver Module I2C 16 Segment 8 Common LED Dot Matrix Module with Keyscan for Arduino: Amazon.com: Industrial & Scientific