TRS-80 Tandy Computer 3 (CoCo3) 512K Memory upgrade and Hitachi 6309 CPU Combo

The smallest RAM upgrade available for the Tandy Color Computer 3 (CoCo3). Great for a second CoCo3. About the 512K board 512K SRAM - low power consumption, no external power source needed. This is a Hitachi 6309 with a external clock CPU option - noted with the E designation.