[ insider_reports_insider ]
The History Of NSA Computers, Up Until 1964. Part II.
Alex Trent
Staff Writer
2010-06-03
 Insider Reports RSS Feed
Recently a formerly classified document was declassified describing how the NSA used computers to crack codes.
 | | The History Of NSA Computers, Up Until 1964. Part II |  |
In Part I, we talked about ATLAS I. The NSA's first real computer. The successor to ATLAS I was named, appropriately enough, ATLAS II.
Even before ATLAS I arrived, ATLAS II's construction was being planned. ATLAS II had several important improvements over ATLAS I. Instead of drum storage, it had high speed electronic static storage in the amount of 1,024 words. The word size was 36 bits instead of ATLAS I's 24, two address logic instead of one, more sophisticated instruction code, and the basis of all computing today, input-output program controlled instructions. Having two-address logic instead of one was very powerful for computers of this age. The new instruction codes included another first, a 'repeat' instruction, some arithmetic instructions, a scaling factor ability, and index jumping capability.
There were actually two ATLAS II's. One arrived in October of 1953 and another in December of 1954. The second ATLAS II's only modification to the original design was the replacement of the electro-static tube memory with high-speed ferrite-core memory. In the planning of ATLAS II, the design had originally planned to use Raytheon magnetic-tape with one character per frame. But to conform to the established data representation that required three frames per character, the change was made to use three. Later, the NSA seems to have regretted this decision as they tried to redesign the magnetic-tape operations, but never succeeded in making the system more efficient.
The ATLAS II computers were very reliable systems for the most part, but the first ATLAS II required a bit more maintenance because of its electrostatic tube storage. The first UNIVAC commercial line of computers the 1101 and the 1103 were based on ATLAS I and ATLAS II respectively. The SOLO, the first transistorized computer, was based on ATLAS II. The two ATLAS II computers were taken out of operation in 1960 and 1962.
Next time, we'll cover the NSA's computers called ABNER and BAKER.
For more in depth reading see: http://www.governmentattic.org/3docs/NSA-HGPEDC_1964.pdf.
View All Articles by Alex Trent
About the Author:
Alex is a staff writer for SecurityProNews.
More insider_reports_insider Articles
Insider Reports RSS Feed
|
|
iEntry 10th Anniversary
RSS
Archive
