ASIC and FPGA designer Sven Anderson continues his "Retrospective" series with reflections on the (r)evolution he's seen with regard to computer memories.
When the Intel 1103 memory first came out, Ericsson started to replace the huge magnetic-core memory units in their systems with memory boards populated with much smaller semiconductor memories. In this way they could fit much more memory in the telephone switches while -- at the same time -- reducing power consumption.
Starting in 1975, Ericsson began to purchase hundreds of thousands of 1103 memories, and the engineers soon ran into the same problems as they had with the standard logic devices -- poor quality. They also realized that the expensive tester they had bought from Tektronix just a few years ago was not suited for testing memories. This was due to the fact that long algorithmic test patterns had to be generated in irder to test memory devices, but the S-3260 system had only a 1K shift register behind every tester channel.
Thus, the search for a dedicated memory tester commenced. Eventually, the MacroData MD104-M was selected...
MacroData started 1969 in Woodland Hills, Calif., and its first memory tester -- the MD100 -- was a great success. This became the major tester for early semiconductor memories, including the 1103, the 2048, and the 4096. The test board plugged right into the front panel and for every pin there was a lamp that switched on every time the pin went high. Running at up to 5MHz, this tester could generate walking ones, marching ones, galloping ones, and butterfly patterns.
A MacroData MD-100 memory chip tester.
When Intel needed a new tester for their growing memory business, MacroData won the order with their new MD-104M memory tester. An example of this tester is shown in the following picture, which was taken on the test floor at Ericsson.
A MacroData MD-104M memory chip tester on the test floor at Ericsson.
In front of the tester is an automatic package handler with a heat chamber. The memory devices were tested at an elevated temperature to make sure they would function in the warm working environment.
This tester was delivered to Ericsson in 1976. In July of that year, a group of test engineers from Ericsson in Sweden were sent to Woodland Hills in California for a four-week training class. As you can see in the following picture, bell-bottoms were still popular at that time (yes, it is me in the blue jeans and with the big glasses).
Spending four weeks so close to Los Angeles gave us plenty of time to visit all the major tourist attractions. For example, a few of the things we experienced were as follows:
- Sea World in San Diego
- Busch Gardens in Van Nuys (closed in 1979)
- Universal Studios
- Hollywood Bowl listening to Roberta Flack singing "Killing you softly"
Also, I cannot neglect the fact that the movie Jaws had its premier in 1975 and quickly became the highest-grossing film in history at that time. In April 1976, the Jaws attraction opened at Universal Studios in Hollywood, and in July 1976, I shot the following picture of the giant shark:
You have to admit that this was perfect timing. And the interesting thing with regard to this column is that no memory was used at all, because this image was captured an old-fashioned 35mm camera using Kodachrome film. In those days, I never dreamed that one day I would own a digital camera capable of holding thousands of images -- all made possible by the r(evolution) in semiconductor memory.