CDC 3000 series

The upper 3000 series uses a 48-bit word size. The first 3000 machine{{cite web == Lower 3000 series ==

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 (February 1965), and the CDC 3300 (December 1965). The final machine in the series, the CDC 3500, was released in March 1967 and uses integrated circuits instead of discrete components. The 3300 and 3500 have optional relocation capabilities, floating-point arithmetic, and BDP (Business + Data Processing) instructions. These machines were targeted towards business and commercial computing. == The 3150 ==

Control Data Corporation's CDC 3150 was described as a "batch computer," and it included a FORTRAN{{cite web == Instruction sets ==

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. == Memory ==

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. == Architecture ==

The lower 3000 CPU uses a 24-bit architecture:{{cite web 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. Much of the basic architecture design of the 3000 series was done by Seymour Cray, then passed on to others to complete as he moved on to designing the CDC 6000 series. Several of the innovative features that made the 6600 'the first supercomputer' can be seen in prototype in the 3000 series. == Software ==

The operating systems for the upper 3000 are called SCOPE (Supervisory Control Of Program Execution). Tape SCOPE is a serial batch OS with no buffering for card reading or print spooling. Drum SCOPE upgraded performance and features print spooling. CDC developed a OS for the 3800 called SUMMIT (Simultaneous Usage of Multiprogramming, Multiprocessing with Interactive Timesharing) to take advantage of hardware's advanced features. Because CDC focused all its resources in advancing the 6600 system, SUMMIT was never released. The earliest operating system for the lower 3000 series was called RTS OS. However, it was quickly replaced with MSOS (Mass Storage OS). The premier operating system for the CDC 3300 and CDC 3500 is called MASTER (Multi Access, Shared Time Executive Routine). MASTER is a multi-tasking, disk-based OS but still oriented for batch jobs. Card jobs are cached to disk and printer output spooled. MASTER optimizes memory usage with page-mapping hardware. An operating system called REAL-TIME SCOPE exists for both lower- and upper-3000 systems. A disk-based version of SCOPE was eventually made available for the upper-3000 systems. == Character set ==

The operating systems for the CDC 3xxx typically use six-bit characters, so the 64 character set does not contain lowercase letters. The character set contained (in display code order): : A-Z 0-9 + - * / ( ) $ = (space) , . # [ ] % " _ ! & ' ? @ \ ^ ; This six-bit extension of the four-bit BCD encoding is referred to as BCDIC (BCD interchange code.) IBM later extended this code further to create the eight-bit "extended BCDIC", or EBCDIC code. Depending on the device, some characters are rendered differently, especially the line printer and some terminals: Note the absence of control characters, especially carriage return and line feed. These are encoded by the record structure. == Partial list of users ==

United States Oregon State University offered a CDC 3300 for use from the mid-to-late 1960s up until about 1980. The U.S. Internal Revenue Service used CDC 3000 series computers for many years. A number of CDC 3000s were installed in France, either in academic computing centers, in software companies or in the aeronautics, nuclear and oil industries. The University of Oslo had a CDC 3300 (1967 - 1976) One CDC 3300 was installed in the late 1960s in England, in Computation Research & Development Ltd, a London-based subsidiary of the civil engineering designers Freeman Fox & Partners. It was used for engineering calculations and commercial computing. It was de-commissioned in 1974. The German Meteorological Service Deutscher Wetterdienst used a CDC 3800 and CDC 3400 for numerical weather prediction in late 1960s. Oceania 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. Communist bloc Communist-ruled Hungary obtained a CDC 3300 machine between 1969 and 1971. It was administered by the National Academy of Sciences throughout the 1970s, mainly for running scientific computations. Other CDC 3300 systems installed in former Eastern Bloc countries • Central Statistical Office, Prague. • Romanian Aircraft, Bucharest (3500 System) == Standard peripherals ==

• 405 - Card reader. 80 column 'high-speed' punched card reader • 415 - Card punch, 80 column card punch • 501 - Line printer, rotating drum, 136 character wide printer. Note that there were no lower case letters. • 505 - Line printer • 512 - Line printer, chain type • 601 - Magnetic tape drive • 604 - Magnetic tape drive • 607 - Magnetic tape drive • 609 - Magnetic tape drive (9-track) • 700 series - Optical page reader • 800 - Rotating magnetic memory series • 808 - Rotating disks, approx 32 inches per disk, approx 32-36 disks per spindle. • 852 - Disk drive with removable media pack, 2 to 3 million seven 7-bit characters, six disks (10 recording surfaces)/pack. Data-compatible with IBM 1311 • 853 - Similar to 852, 4 million characters. Media mechanically interchangeable with IBM 1311, but not recorded data • 854 - Similar to 853, 8 million characters • 915 - Optical page reader The CDC 6000 series were also initially marketed with many of the same peripherals. ==Images==