Lot of 5 large, heavily populated vintage IBM MST (Monolithic System Technology) circuit boards from the 1970s. These are the classic square aluminum-capped hybrid modules marked “IBM 22” that were used in IBM System/370 mainframes and related equipment.

All five boards are the larger, densely populated style with dozens of the silver aluminum-can chips, orange capacitors, and gold-plated edge connectors. Boards vary slightly in exact layout but are all similar in size and chip density to the examples shown in the photos.

• Untested – sold as-is for collectors, display, restoration, or parts

• Original IBM markings and date/lot codes visible

• Gold-plated edge connectors

• No major cracks or broken connectors observed

• Some boards have original IBM stickers (GA, GD, etc.)

These boards are becoming harder to find intact. Most were scrapped decades ago. Great for a vintage computer collection, museum display, or as a conversation piece.

Please review all photos carefully — what you see is what you get. Boards will be packed securely with plenty of padding.

Questions welcome. Thanks for looking!

Item specifics (suggested)

• Brand: IBM

• Type: Mainframe Circuit Board / MST Module Card

• Era: 1970s

• Country/Region of Manufacture: United States

• Vintage: Yes