How it Works

Instead of storing data in relatively fragile, rewritable hard drives, tapes, or optical discs, 3D Printed ROM employs many thousands of batteries of precision ejection nozzle to simultaneously physically print your data into a solid, permanent, and simply addressable electronic circuit, layer by layer.

Your data is stored in a solid block of conductive metal and insulative hard resin that can be destroyed, but only with some extreme effort, such as using a hammer, chainsaw, or kiln/furnace.

The result is a Write Once Read Many-times (WORM), tamper-proof, permanent solution for record keeping, cryptographic, identification, or hashing keys, and secure code.

No more blockchains. No more managing many redundant copies across dozens of drives. No more replacing failed drives, periodic data refreshing, and so on. Just write it once. It never changes. Ever.

Two Products

The first product is a Write Once, Read Many-times (WORM) data storage device named the Diom Eon Drive for secure, permanent record keeping. A large, rugged, heavy, and effectively immovable device, built for maximum physical and data security and described further on the Eon Drive page.

The second product is much smaller. The Diom Block is pre-written blocks of data for direct integration into secure electronic or computer systems, including mobile systems. These smaller, pre-encoded modules are typically one of the following:

1. Long crypto or hash keys used for secure communication or data authentication between devices.
2. Program instructions for secure computing devices.
3. Very long unique identifiers or access keys for use in security fobs or product tracing devices.

Capacity

The initial capacity of an early-stage Write Once, Read Many-times (WORM) data storage device, capable of achieving 10 bits per millimetre in each dimension, provides approximately one gigabyte of storage within a typical 200 × 200 × 200 mm memory block.

Later, more developed products will have much greater capacities, as shown in the table below.

Diode Matrix Memory

Diode matrix memory is an early form of non-volatile read-only memory (ROM). It stores data in a grid, or matrix, of diodes. An often-overlooked digital memory type, diode matrix memory was prevalent for a time before silicon-based memory and magnetic tapes and hard drives became dominant.

Early diode matrix memory was typically built by hand as a 2D grid of wires on a wooden frame. In the grid, a 2D plane containing a series of equally spaced parallel row wires is offset a small distance from a second parallel 2D plane containing equally spaced column wires oriented at a 90° angle to the row wires.

The two separate planes of wires form a grid with small gaps at the intersections of the column and row wires. Using the rows as address lines and columns as data lines, each intersection becomes a place where a bit of data can be stored. By physically soldering diodes by hand at the intersections, a high bit (1) can be represented. Leaving a gap at an intersection represents a low bit (0). Layers of these grids of wires can be stacked on top of each other to increase the capacity of the system.

Diodes are required because, if simple bridging connections or resistors were used instead, part of the current from an output data wire would flow backward through other high-bit connections on that same output data wire to unselected input address wires. This creates weaker stray currents on unselected address wires, which in turn pass unintended data through unaddressed connections, diffusing the intended output signal. The accumulation of this diffusion quickly makes it impossible to distinguish the correct bit states.

A Little History

Methods similar to, or equivalent to diode matrix memory were first used in the 1940s and 1950s in programmable industrial machines and the earliest computers. These systems were often built by hand by carpenters, electricians, and technicians.

In the 1950s and 1960s, diode matrix memory was used in mainframe computers, where it helped store microprograms and firmware that did not need to be altered frequently. IBM, for example, utilized diode matrix memory in some of its early computers for control functions and fixed programs. The Whirlwind Project, which assisted with early military aircraft design, and the Minuteman I intercontinental ballistic missile guidance system both used diode matrix memory.

The decline of diode matrix memory came in the 1970s, as semiconductor-based ROM technologies such as PROM (Programmable ROM) and EPROM (Erasable Programmable ROM) emerged. These new technologies offered greater density, smaller physical size, and the ability to be programmed or reprogrammed without rebuilding, making them more versatile and cost-effective. By the late 1970s, diode matrix memory had been largely replaced by integrated-circuit-based ROMs in computers and other electronics.

While silicon-wafer, optical, and magnetic-field-based memory types dominated for decades due to the advantages of mass production, today’s trend toward flexible manufacturing systems and additive manufacturing makes the concept of diode matrix memory, with its many advantages, once again a feasible solution for specific data-storage applications.

This modern implementation of diode matrix memory utilizes thousands of batteries of ejection nozzles, rapidly printing circuits that contain row and column wires, diodes, and insulating material instead of air gaps for zeros. By combining conductive, insulating, and semiconductive materials from different ejection nozzles within each battery, an addressable diode matrix memory can once again be a practical and profitable venture.