NEC System Unit (1984)

NEC System Unit (1984)
  • Model: S430
  • Device: System unit
  • Released in: February 1984


  • Operating system: ACOS-4
  • Number of arithmetic processing units: 1
  • Max. main memory capacity: 16MB
  • Max. number of channels: 12
  • Max. data transfer speed: 20 Mb/s
  • CPU element: CMOS
  • Memory element: 256Kbit DRAM


S430 machine was introduced as a mid-size machine which gained popularity as the successor of ACOS System 350 in February 1984. The S430 system contained the main memory which consists of 256 kilobit DRAMs, 16000 gate CMOS custom LSIs for the central processing unit, and was equipped with a 4,400 gate CMOS gate arrays and other high density logic LSIs.

S430 system was a machine with expanded functionality, and also achieved smaller size, higher speed, lower power consumption, and higher reliability which marks a great improvement in the computing industry.

S430 has relatively closer features with S350. S340 has additional features like paging capability and dynamic address transformation (DAT) for input/output channel operation. These new features helps S4340 to work on wider range of tasks such as data processing, office automation, CAD and R&D.