Early 1970's AMD 1402A - Rare white ceramic fifty year old Shift Register/Memory

Description: This sale is for one white ceramic and gold chip as pictured. May have tiny spots of age discoloration like those shown in the photos, but overall they are excellent specimens. Straight from the original manufacturers shipping tube. The chip shown is the quality you should expect to receive. Cutting open a fifty year old gold plated chip, isn't something I like to do without good reason. The inside photos here justify the sacrifice of one piece. Look closely at the die and you can see the register chains, clock lines, and power distribution. Wish I had a better scope. For a short period of time in the early years of solid state calculating and computing this type device became popular as a solid state memory element, but within just a few years they virtually disappeared as RAM dominated and packaging technology advanced. Pin count was a major issue that made serial memory chips attractive in the early seventies. At that time few large pin count packages existed, nor the equipment to make and handle them. Compare the AMD 1024 bit 1402A, to the 64 bit Intel 3101 RAM device. The 1402A put sixteen times the storage into the same 16 pin count package. Although far slower than RAM, it was a major reduction in both memory size and power consumption in applications where memory speed is not an issue. The 1404/1403 versions used the same die and came in metal cans using even less space and pins. Shift registers made of chained flip-flops are used to implement many logical operations in computers. When those flip-flops are arranged in long chains they can be and were used as serialized memory. The bits move through the chain with precision timing, advanced by a two phase master clock. A simple counter running off the same master clock could then be used to track witch bit was currently present at the input or output. I know it sounds cumbersome, but in the early seventies there were no widely available alternatives to memory this dense and easy to use. Fairchild, TI and their offshoots AMD, Intel, Mostek all produced several versions of Shift Register/FIFO memory during this time. These were some of the pioneers of the technology and some of the very few companies that had the capability to produce such devices. The white ceramics and metal can packages are both rare finds today. I got a great deal on them, so I'm passing it on. See many other tech collectibles in my ebay store and hope you enjoyed looking.

Price: 22.5 USD

Location: Huntsville, Alabama

End Time: 2025-01-08T17:00:14.000Z

Shipping Cost: 5 USD