Computer history: System 17 equipment

CDC System 17 computer hardware characteristics

Below is the description of the Control Data Corporation (CDC) System 17 computer equipment that was in use at the TNO Physics Laboratory between the seventies and eighties.

Type/Model	Description
DISK SUBSYSTEMS
CDC 1733-2	CARTRIDGE DISK CONTROLLER Single direct memory access channel connection. The controller has absolute cylinder addressing and a daisy chain capability to control up to four cartridge disk drives with seek-overlap capability in any combination. Occupies five pre-assigned positions in CPU enclosure.
CDC 856-4	CARTRIDGE DISK DRIVE Cartridge disk drive with voice coil positioning. Stores 2.2 million words on a fixed disk plus 2.2 words on a removable disk. Each disk has two surfaces, 400 tracks per surface, 29 sectors per track, and 96 words per sector. The average positioning time is 35 milliseconds. The rotational speed is 2400 rpm. The transfer rate is 156.000 words per second. Includes floor mount cabinet. Requires 848-29 disk cartridges (not included).
TAPE SUBSYSTEMS
CDC 1732-2/615	7- and 9-track tape drive. 37.5 ips, 556/800 bpi NRZI and 1600 bpi Phased encoded (PE).
UNIT RECORD
Papertape station	400 characters per second, paper tape reader capable of reading 5, 7 or 8 level tape, 150 characters per second paper tape punch, includes common control cabinet and power supply.
GRAPHICS
Digigraphics workstation	Digigraphic with light pen Vector-oriented 22-inch flat face CRT console, screen capacity of up to 2,000 inches of curves or up to 1800 characters of any size or font, includes character generator and light pen. It required a controller that controls a single 274 graphics console for light pen-based computer-aided design, research and control application, contains 4096 words memory buffer, and operates from one 1700 data channel. Cycle time was 1.67 microseconds; the refresh cycle was 25 ms. TNO’s system had 8K words.
COMPUTER
System 17	The Control Data Corporation (CDC) System 17 had the 1784 processor and a memory of 16 K words of 16 bits plus 2 parity bits each (=32 Kbyte). The processor cycle time was 0.9 μs. It had two index registers of 8 bits. The average processing time for an addition was 2 μs, a multiplication 7 μs and a divide 9 μs. System 17 evolved to System 18, a system that was the basis for the later 2551 Data Communication computer. A 16 Kwords version of the CDC 1700 was priced Dfl 368.617 in the Spring of 1969. Papertape equipment at that time would cost some Dfl 50.000. System 17(00) (Photo courtesy of computerhistory.org)