74LS189

74LS189 64-Bit RAM with 3-State Output IC

The 74LS189 (also known as the 74189) is a high-speed 64-bit RAM IC organized as a 16-word by 4-bit array, making it a reliable and essential component for maintaining and restoring classic arcade and pinball machines. Many vintage game boards rely on RAM chips like this one to store critical game data, settings, and scores — making a quality replacement like the 74LS189 a must-have for any serious arcade technician or restoration enthusiast.

Housed in a standard DIP-16 package, this IC features fully decoded on-chip address inputs that are buffered to minimize loading, ensuring stable and accurate performance in demanding game board environments. The 3-state outputs enter a high impedance state when the Chip Select (CS) input is HIGH, and output data is presented as the complement of the stored data during Read mode — consistent with the behavior expected by period-correct arcade and pinball hardware.

• 64-bit RAM organized as a 16-word × 4-bit array
• 3-state outputs for bus-compatible operation
• High-speed performance suitable for classic game board applications
• Fully decoded, buffered address inputs to minimize loading
• Output data is complement of stored data in Read mode
• Standard DIP-16 through-hole package
• Compatible with 74189 pinout and applications