View source for UNIVAC I

{{Infobox Machine
| name = UNIVAC I
| manufacturer = [[Remington Rand]]
| <!-- architecture = [[]] -->
| year design started = Early 1947
| year first shipped = March, 1951
| form factor = [[mainframe]]
| word size = 72 bits
| physical address = 3 digits (decimal)
| logic type = [[vacuum tube]]s
| design type = serial asynchronous
| clock speed = 2.25 Mhz
| instruction speed = 120 μsec (add, excluding memory access) <!-- 525 μsec max -->
| memory speed = 400 μsec (maximum)
| predecessor = [[EDVAC]]
| successor = [[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 line]]s for [[main memory]], with 1000 [[word]]s organized as 100 lines of 10 words each (to reduce access times over fewer, larger lines). The [[Central Processing Unit|CPU]] operated in digit-serial mode (i.e. a digit at a time), to match the memory. Its [[word]] size was 72 bits, with two [[instruction]]s per word, with 12 digits/characters per word; it stored numbers with a form of [[binary-coded decimal|packed decimal]], with digits being represented as their character equivalents.

The only [[input/output]] devices were [[magnetic tape]] units, the 'UNISERVO'. Data could be transferred to and from tape with off-line [[peripheral]]s which allowed use of printing, [[keyboard]] input, and [[punched card]]s.

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.)
 
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[[Category: Computers]]