AMD AM2764ADC 64K 8K x 8 UV Erasable EPROM 28-Pin Ceramic DIP Vintage Memory IC

Original AMD AM2764ADC ultraviolet-erasable programmable read-only memory in the desirable 28-pin ceramic DIP package with exposed quartz erase window. The device provides 65,536 bits of storage organized as 8K x 8 and operates from a nominal 5 V supply.

The device is marked AM2764ADC and 12.5V PGM, identifying the 12.5 V programming-voltage version. The ceramic windowed package allows the stored contents to be erased using the proper ultraviolet EPROM eraser so the device can be reprogrammed.

The reverse of the package is clearly marked MALAYSIA, documenting the country of assembly/manufacture for this example.

This device was recovered from donor equipment and is being offered as a vintage donor pull for restoration, experimentation, or legacy equipment support.

Lifecycle: OBSOLETE.

HISTORICAL BACKGROUND: Advanced Micro Devices was founded in Sunnyvale, California in 1969 by Jerry Sanders and a group of semiconductor-industry veterans. AMD became one of the major American semiconductor manufacturers, producing logic devices, memory, microprocessors, programmable devices, and numerous second-source components for the rapidly expanding computer and industrial electronics markets.

During the late 1970s and 1980s, UV-erasable EPROMs became one of the most important forms of nonvolatile semiconductor memory. Before electrically erasable EEPROM and flash memory became commonplace, EPROMs provided equipment manufacturers and engineers with a practical way to permanently store firmware while retaining the ability to erase and rewrite the device during development, servicing, or equipment upgrades.

The 2764 generation represented a substantial increase in capacity over earlier devices such as the 2708, 2716, and 2732. A 2764 stores 64 kilobits arranged as 8,192 eight-bit words, providing 8 KB of firmware storage in a single 28-pin package.

Devices of this class became common in early personal computers, industrial controllers, communications equipment, test instruments, embedded systems, development hardware, arcade-related electronics, and many other microprocessor-controlled products of the 1980s and early 1990s.

The transparent window in the ceramic package exposes the silicon die to ultraviolet light. Extended exposure to the correct UV wavelength removes the stored charge from the floating-gate memory cells, returning the EPROM to an erased condition so that new firmware can be programmed.

The ceramic DIP construction itself is also significant. Windowed ceramic packages were considerably more expensive to manufacture than later plastic OTP versions, but they were necessary when repeated erasure and reprogramming were required. Original ceramic AMD EPROMs are therefore increasingly collected alongside their continued practical use in vintage-computer and industrial-equipment restoration.

This particular example was assembled in Malaysia, reflecting the global semiconductor manufacturing network AMD and other American semiconductor companies developed during the period while design and corporate operations remained centered in the United States.