Hewlett Packard, 9815A desktop programmable - Calculator - 1970-1980

# Rare Vintage HP 9815A Computing Calculator (1975) – Working & Boots Up!

Up for sale is a true milestone in computer history: the Hewlett-Packard 9815A Desktop Computer / Programmable Calculator. Introduced in 1975, this iconic machine represents a major architectural leap for HP. It was their very first desktop system to move away from multi-chip custom architectures to a standard microprocessor—the legendary Motorola 6800.

For retro-computing enthusiasts, collectors, or museums, this is an absolute centerpiece that beautifully showcases mid-1970s hardware engineering.

### Why the HP 9815A is a Holy Grail for Collectors:
* Microprocessor Pioneer: Driven by an early Motorola 6800 CPU paired with HP’s proprietary Loveland NMOS II support chips.
* Iconic Display: Features the beautiful, bright single-line gas-plasma display, fully sharp and readable.
* Tape Drive Innovation: The first HP machine designed around the revolutionary mini-cartridge DC100 tape system.
* Integrated Printer: Comes with the built-in 16-character thermal strip printer.
* Classic HP Feel: Uses HP's renowned RPN (Reverse Polish Notation) logic with an incredibly satisfying, tactile keyboard click.

### Specifications:
* Manufacturer: Hewlett-Packard (Calculator Products Division)
* Release Year: 1975
* Logic: RPN (Reverse Polish Notation) with a 4-level stack
* Expandability: Features two rear I/O slots for interfacing (e.g., HP-IB).

### Condition Report (Actual Status):
* Technical Condition: Working and operational! The machine powers on perfectly, the gas-plasma display is bright and sharp, and all keys register with a solid click.
* Printer Condition: The thermal printer mechanism works beautifully! It prints crisp, dark, and clear characters on the paper strip.
* Tape Drive & Tapes: The tape drive mechanism itself is fully functional and spins the tapes as intended. However, due to the natural degradation of the 50-year-old magnetic DC100 tape media (magnetic oxide loss), the tapes do not consistently read or output all data blocks/programs. The machine hardware itself is fine; the vintage tape media has simply aged.
* Cosmetic Condition: Excellent vintage condition with some signs of age. The chassis is clean, labels are intact, and it looks great on a desk.
* Included Accessories: [e.g., Original power cord / 10 DC100 tapes.

### Shipping & Packaging:
* International Shipping: Available worldwide. This heavy machine will be packed with extreme care using heavy-duty bubble wrap and a double-walled box to ensure safe transit.

Don't miss the chance to own a rare, functioning piece of computing history. Perfect for display, serious collectors, or as a museum-grade investment!