System/360 Model 50

IBM System/360 Model 50

IBM System/360 Model 50
Announced April 7, 1964 and
withdrawn March 15, 1977.

The IBM System/360 Model 50 had approximately ten times the internal power of the Model 30 when performing a mix of computations. It was the most powerful unit in the medium price range with communication facilities.

Typical arithmetic operations per second

  Decimal add (5 + 5 digits) 50,000
  Fixed point add (1 word + 1 word) (32 bits) 307,600
  Fixed point multiply (1 word x 1 word) 36,000
  Fixed point divide (2 words div. by 1 word) 28,700
  Floating point multiply (1 word x 1 word) 48,200

Feeds & speeds

Speed Data width (bits)
Machine cycle time 500 nanosec.  
Logic circuits 30 nanosec. 32
Memory cycle time
    64K, 128K, 256K
2 microsec. 32
Registers
    16 general purpose
    4 floating point

500 nanosec.
1 microsecond

32
64
Control
    Read only storage

500 microsec.
 
Bulk core storage
    1,048,576 to 8,388,608
8 microsec. 32
Data rate
per channel
(Char. a Sec.)
Control units
per channel
I/O units
per channel
Channels:
    Selector
    (up to 3)

800,000

8

256 each
 
    High Speed

1,250,000
   
    Multiplexor
      Multiplex mode
      Burst mode

40,000
200,000

8

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