UNIVAC 1103A

The UNIVAC 1103A or Univac Scientific was an upgraded version introduced in March, 1956. Significant new features on the 1103A were its magnetic core memory, and the addition of interrupts to the processor. The UNIVAC 1103A had up to 12,288 words of 36 bit magnetic core memory, in one to three banks of 4,096 words each. Fixed-point numbers had a 1 bit sign and a 35 bit value, with negative values represented in ones' complement format. Floating-point numbers had a 1 bit sign, an 8 bit characteristic, and a 27 bit mantissa. Instructions had a 6 bit operation code and two 15-bit operand addresses.