Giddings & Lewis CMOS Memory Board 501-04090-00 / 502-03274-00

Used in Giddings & Lewis CNC control systems, the 501-04090-00 CMOS Memory Board is a full-size backplane-mounted circuit board identified by part number 501-04090-00 and assembly number 502-03274-00, with a manufacture date of 12/83. The board label reads "CMOS MEMORY BD." and is manufactured by Giddings & Lewis. The board features multiple rows of CMOS memory ICs across a large green PCB with gold-finger edge connectors on both sides. Battery backup is provided by three Panasonic BR-2/3A 3V lithium cells along with a Gold Cap supercapacitor rated at 5.5V 0.33F, which together maintain CMOS memory contents during power-off conditions. Silkscreen designators indicate multiple memory banks labeled 0-16K, 16K-32K, 32K-48K, and 48K-64K, suggesting a total addressable capacity across those ranges. Board markings also reference part 302-70164-00 and 88164-00 on a small sub-assembly. A barcode label with internal tracking number 102000 is affixed to the lower left corner. This board is associated with the Giddings & Lewis Series 900 or similar CNC controller platforms that utilized large-format CMOS memory expansion boards. The secondary part number 502-03274-00 is also visible on the board label.

Stock # 0226-721