CDC 3000 сериялы ЭЕМ: Тарихы мен сипаттамасы

The CDC 3000 series ("thirty six hundred" or "thirty one hundred") are a family of mainframe computers from Control Data Corporation (CDC). The first member, the CDC 3600, was a 48 bit system introduced in 1963. The same basic design led to the cut down CDC 3400 of 1964, and then the 24 bit CDC 3300, 3200 and 3100 introduced between 1964 and 1965. The 3000 series replaced the earlier CDC 1604 and CDC 924 systems. The line was a great success and became CDC's cash cow through the 1960s. | 714 kHz (1.4μs cycle)
| 1.536 megabyte (262144 x 48 bits) to be produced was the CDC 3600; first delivered in June 1963. First deliveries of the CDC 3400 and CDC 3800 were in December 1965. These machines were designed for scientific computing applications; they were the upgrade path for users of the CDC 1604 machines. However these machines were overshadowed by the upcoming 60 bit CDC 6000 series machines when the CDC 6600 was introduced in December 1964 and delivered in 1965. Some high end computer labs purchased these machines as stopgaps, while waiting for delivery of their 6600 machine. (CDC had indicated that the 6600 machines would use the same assembly language.)

The lower 3000 series use a 24 bit word size. They are based on the earlier CDC 924 a 24 bit version of the (48 bit) CDC 1604. The first lower 3000 to be released was the CDC 3200 (May 1964), followed by the smaller CDC 3100 and it included a FORTRAN and a COBOL compiler. Its console looked like this.

The instruction set of the upper 3000 series is composed mostly of 24 bit instructions (packed two per word), but also contained some 48 bit instructions. The lower 3000 is based on a 24 bit subset of those available on the upper 3000 systems. It is therefore possible to write programs which will run on all 3000 systems. And as these systems were based on the prior 1604 and 924 instruction sets, some backward compatibility also exists. However the systems do diverge from each other in areas such as relocation and the BDP instructions.

All 3000 series computers use magnetic core memory. The CDC 3500 machine use the same core memory modules as used in the CDC 6000 / Cyber 70 series computers.

The lower 3000 CPU uses a 24 bit architecture: instructions are 24 bits in length, as are the two operand registers A and Q. There are four index registers of 15 bits, B0 through B3, though B0 is always zero (zero when read; writes do not affect the value). There is no status (flags or condition code) register. Up to 32,768 words of core memory, 24 bits per word, can be directly addressed, and multiple banks can be switched in. Two or three memory bank configurations are the most common. Each instruction contains six bits of opcode, one bit specifying whether indirect addressing used, two bits of index register address and fifteen bits of address. Arithmetic uses ones' complement, so there are two forms of zero: positive zero and negative zero. The A and Q register can function as a combined 48 bit register for certain arithmetic instructions. The E register has 48 bits. The 3600 CPU can execute around one million instructions per second (1 MIPS), giving it supercomputer status in 1965. FORTRAN, COBOL, and ALGOL were available. The assembly language was called COMPASS. These were available from CDC. An APL system for the upper 3000 series computers was developed at the University of Massachusetts Amherst. This system was made available to other users of the upper 3000 series.

There were many CDC 3000 series machines in Australia. CSIRO had a 3600 installed in Canberra in 1964, with satellite 3200 machines in Melbourne, Sydney, and probably Brisbane and Adelaide. The Bureau of Census and Statistics had a 3600, 3300, and a 3500 in Canberra, with a 3200 in each of the six state capitals several of which were upgraded to 3300s about 1970. Monash University had a 3200 delivered in 1964. Defence Signals Directorate had at least one. BHP had two 3300 machines at each of its Newcastle and Port Kembla Data centres. They were replaced by 3500s in 1977, and remained in operation until the mid 1980s.