GE A20B-0004-0500 Control Program Memory PCB

Technical Specifications

Physical Layout and Component Distribution

This A20B-0004-0500 memory board measures 7.2 inches in length. Its width reaches 5.0 inches with a thickness of 1.2 inches. The total weight comes to approximately 0.85 pounds. Manufacturers populated this PCB with 112 discrete components. These components include memory chips, address decoders, and bypass capacitors. The four-layer board design minimizes signal reflection and cross-talk.

Memory Architecture and Storage Resources

A20B-0004-0500 provides four 28-pin EPROM sockets on the board. Each socket accepts industry-standard 27256 or 27512 EPROM chips. The total program storage capacity reaches 512 kilobytes. For temporary data, the board includes 128 kilobytes of static RAM. A 3.6V lithium battery backs up the static RAM contents. This battery maintains data for approximately five years under normal use.

Energy Storage and Power Requirements

The memory PCB integrates six 47µF tantalum capacitors. These capacitors filter high-frequency noise from the power supply. For stable operation, the board requires a 5V DC supply with ±5% tolerance. Total current consumption measures 180 milliamps from the 5V bus. Address decoding logic uses CMOS technology for low power draw. Consequently, the board generates minimal heat during extended operation.

System Integration and Application Use

You will find this board inside GE CNC control cabinets. It stores machine tool operating parameters and part programs. The A20B-0004-0500 operates reliably from 0°C to 55°C ambient. Field technicians can replace EPROM chips without removing the entire PCB. Therefore, this memory board offers convenient firmware updates for legacy equipment.