UNIVAC I
| UNIVAC I | |
| Manufacturer: | Remington Rand |
|---|---|
| Year Design Started: | Early 1947 |
| Year First Shipped: | March. 1951 |
| Form Factor: | mainframe |
| Word Size: | 72 bits |
| Logic Type: | vacuum tubes |
| Design Type: | serial asynchronous |
| Clock Speed: | 2.25 Mhz (basic - serial machine; add - 120 μsec for operation, 525 μsec for complete instruction) |
| Memory Speed: | 400 μ sec (maximum) |
| Physical Address Size: | 3 digits (decimal) |
| Predecessor(s): | EDVAC |
| Successor(s): | UNIVAC II |
| Price: | US$1250-1500K (system) |
The UNIVAC I ('UNIVersal Automatic Computer'; originally, just plain 'UNIVAC', until later models appeared) was the first commercially-available computer in the US.
It was a vacuum tube machine, using mercury delay lines for main memory, with 1000 words organized as 100 lines of 10 words each (to reduce access times). The CPU operated in serial mode (to match the memory). Its word size was 72 bits, with two instructions per word.
The only input/output devices were magnetic tape units, the 'UNISERVO'. Data could be tranferred to and from tape with offline peripherals which allowed use of printing, keyboard input, and punched cards.
A careful, slow power-on procedure, in which the filaments in the tubes were slowly warmed up, produced very reliable operation. (No doubt prior experience with tubes in the ENIAC had educated the UNIVAC's builders.)
