How does shipping work for orders on MRO Exchange?

Most orders ship within 1–2 business days via UPS. Larger equipment ships via freight carrier, and customers can use the shipping estimator on the product page for a location-specific quote. Local pickup is also available at the Fairfield, IL facility, typically ready within 4 hours.

What payment methods does MRO Exchange accept?

MRO Exchange accepts all major credit cards, PayPal, and Shop Pay. Purchase order and wire transfer payment is also available, with payment due prior to shipment. Custom terms are available for established accounts.

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

$899.99 USD

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✓ 30-day returns on every item — return policy

ConditionSurplus - Untested MPN501-04090-00 / 502-03274-00 Stock #0226-00721

30-day returns on every item. Photos reflect the actual item’s current condition — see our return policy and condition guide.

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⚡ Same-day shipping available — order by 11 am CT ($100 add-on at checkout)

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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

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Shipping & Handling

Most orders ship within 1–2 business days via UPS, but expedited same-day handling is available as an add-on to orders in cart. Larger equipment ships via freight carrier. Use the shipping estimator above for a location-specific quote. Local pickup is also available at our Fairfield, IL facility, typically ready within 4 hours.

Returns & Condition

All items are sold as-described based on the photos and condition listed. If an item arrives differing from its description, it may be eligible for return or refund. See our full condition guide for details on our grading terms.

Payment Options

We accept all major credit cards, PayPal, and Shop Pay. Purchase order and wire transfer payment is also available by selecting "Purchase Order / Wire Transfer" at checkout. Payment is due prior to shipment. Contact us for custom terms on established accounts. Tax exemptions are honored if proper documentation is provided.