Seymour Cray and his team at Control Data Corporation created and created the 48-bit CDC 1604 computer (CDC). One of the first transistorised computers to be commercially successful was the 1604. In November 1959, the IBM 7090 was delivered (earlier). According to legend, Cray’s previous project, the ERA-UNIVAC 1103, was given the 1604 name by adding CDC’s initial street address (501 Park Avenue). Shortly after, a 24-bit version that had been reduced in size was created and given to NASA.
In January 1960, the first 1604 was delivered to the U.S. Navy Post Graduate School for use in applications supporting significant Fleet Operations Control Centers, particularly for weather forecasting in Hawaii, London, and Norfolk, Virginia. Over 50 systems had been created by 1964. The CDC 3600, which replaced the 1604 and added five op codes, “was mostly compatible” with it.
The Soviet nuclear weapons labs employed the 1604 design. Their BESM-6 computer, which went into production in 1968, was created with software compatibility with the CDC 1604 in mind , but it operated 10 times faster and had more registers.
The CDC 1604’s magnetic core memory has a 32K by 48-bit word capacity and a 6.4 microsecond cycle time. It was divided into two banks of 16K words each, one bank containing odd addresses and the other bank containing even addresses. The average effective memory access time was 4.8 microseconds since the two banks were phased 3.2 microseconds apart. About 100,000 processes are carried out by the computer every second.
The CPU was equipped with a 15-bit programme counter (P), six 15-bit index registers, a 48-bit auxiliary arithmetic register (Q), and a 48-bit accumulator (A). The Q register was typically used in tandem with A to create double-length registers AQ or QA, participate in operations involving multiplication, division, and logical products (masking), and temporarily store the contents of A while using A for another task.
Two 24-bit instructions were contained in each 48-bit word. The instruction format was 6-3-15: three bits for the “designator” (index register for memory access instructions, condition for jump (branch) instructions), six bits for the operation code, and fifteen bits for the memory location (or shift count, for shift instructions).
The United States’ first operational solid-rocket ICBM system was the Minuteman I. Two completely different ground station designs that were created separately exist today. The single silo design, which was more compact and attractive, had two redundant CDC 1604 computer systems, each with twin cabinets that held four 200 bps magnetic tape drives. Information for targeting control and guiding was pre-calculated using the computers. Prior to launch, results based on the current weather and targeting data were transferred into the missile. The Octave Chanute Aerospace Museum in Rantoul, Illinois, has model displays of both of these ICBM ground station concepts, including block replicas of the CDC 1604 computers.
The CDC 924 was a 24-bit computer that allowed “any input-output devices capable of interfacing with the 160 and/or 1604 computer” to be used. Its six independent channels allowed for three simultaneous input operations while three channels simultaneously conducted output.
The 924’s advanced features, which contained 64 instructions, included six registers for indexes. Indirect addressing was reserved for the value “7”. An order to perform (in what the hardware reference manual called “a subroutine of a single instruction”). It consisted strong Storage Search guidelines.