UNIVAC 1105
| Industry | Computer hardware |
|---|---|
| Founded | 1955 |
| Products | UNIVAC 1105 |
The UNIVAC 1105 succeeded the UNIVAC 1103A and was launched by Sperry Rand in September 1958. Its construction incorporated 21 varieties of vacuum tubes, 11 different diode types, 10 types of transistors, along with three distinct core models.
Memory options consisted of either 8,192 or 12,288 words of 36-bit magnetic core memory, organized into two or three banks containing 4,096 words each. Magnetic drum memory was available in capacities of 16,384 or 32,768 words distributed over one or two drums. The system accommodated sixteen to twenty-four UNISERVO II tape drive units, each tape capable of storing up to 1.2 million words. Significant improvements over the 1103A included a buffered Input/Output mechanism featuring two buffers of 120 words, which allowed concurrent reading and writing on magnetic tape.
Data representation included fixed-point numbers with a single sign bit and a 35-bit value expressed in ones' complement, as well as floating-point numbers composed of a one-bit sign, an eight-bit exponent (characteristic), and a 27-bit mantissa. The instruction format contained a six-bit opcode and two operand addresses of 15 bits each.
Operating the full UNIVAC 1105 system necessitated considerable support infrastructure: it consumed 160 kW of electrical power (175 KVA at a power factor of 0.9) and required an air conditioning system capable of handling at least 35 tons (123 kW) for cooling. Physically, the system weighed around and occupied roughly 3,752 ft² (350 m²) within a room measuring 49 by 64 by 10 ft (15 by 20 by 3 m). Additional space totaling approximately 2,450 ft² (230 m²) was allocated for power supply equipment, refrigeration units, and other auxiliary hardware.
Cost, price and rental rates
| Component | Cost | Monthly rental |
|---|---|---|
| Base configuration: magnetic core memory of 8,192 words, magnetic drum memory of 16,384 words, central processor unit, peripheral controller, and sixteen Uniservo II drives | $1,932,000 | $33,060 |
| Optional components | ||
| Additional magnetic core memory (4,096 words) | $195,000 | $4,500 |
| Extra magnetic drum memory (16,384 words) | $60,000 | $1,500 |
| Floating point arithmetic unit | $65,000 | $1,545 |
| Uniservo II tape drive unit | $20,000 | $450 |
| Card input/output device | $55,000 | $1,310 |
| High-speed printing device | $185,000 | $3,300 |
Chapel Hill
In 1959, a UNIVAC 1105 was installed in the basement of Phillips Hall at The University of North Carolina at Chapel Hill, marking one of only three such installations. This machine primarily supported the United States Census Bureau, which operated its own system alongside that at the Armour Institute of Technology. The Chapel Hill facility's installation cost totaled $2.4 million; modifications to the basement—such as adding sixteen-inch-thick concrete walls for nuclear shielding—added an additional $1.2 million. The computer featured less than 50 kilobytes of memory capacity and could execute approximately 30,000 addition operations per second. Its dimensions extended to 60 feet in length with a weight of about 19 tons; it contained around 7,200 vacuum tubes and was equipped with a printer capable of producing up to 600 lines per minute.
See also
- UNIVAC 1100/2200 series
- List of UNIVAC products
- History of computing hardware
- List of vacuum tube computers
External links
- BRL REPORT NO. 1115 March 1961: UNIVAC 1105 authored by Martin H. Weik