ENIAC

context: en: ENIAC could be programmed to perform complex sequences of operations, including loops, branches, and subroutines. However, instead of the stored-program computers that exist today, ENIAC was just a large collection of arithmetic machines, which originally had programs set up into the machine by a combination of plugboard wiring and three portable function tables (containing 1200 ten-way switches each). The task of taking a problem and mapping it onto the machine was complex, and usually took weeks. Due to the complexity of mapping programs onto the machine, programs were only changed after huge numbers of tests of the current program. After the program was figured out on paper, the process of getting the program into ENIAC by manipulating its switches and cables could take days. This was followed by a period of verification and debugging, aided by the ability to execute the program step by step. A programming tutorial for the modulo function using an ENIAC simulator gives an impression of what a program on the ENIAC looked like.ENIAC's six primary programmers, Kay McNulty, Betty Jennings, Betty Snyder, Marlyn Wescoff, Fran Bilas and Ruth Lichterman, not only determined how to input ENIAC programs, but also developed an understanding of ENIAC's inner workings. The programmers were often able to narrow bugs down to an individual failed tube which could be pointed to for replacement by a technician.
qas: question: zh_tw: 程式設計過的 ENIAC 可以執行什麼？
answers: en: text: complex sequences of operations, including loops, branches, and subroutines

context: en: ENIAC was a modular computer, composed of individual panels to perform different functions. Twenty of these modules were accumulators that could not only add and subtract, but hold a ten-digit decimal number in memory. Numbers were passed between these units across several general-purpose buses (or trays, as they were called). In order to achieve its high speed, the panels had to send and receive numbers, compute, save the answer and trigger the next operation, all without any moving parts. Key to its versatility was the ability to branch; it could trigger different operations, depending on the sign of a computed result.
qas: question: zh_tw: 電子數字積分計算機是什麼型別的裝置？
answers: en: text: modular computer

context: en: In 1954, the longest continuous period of operation without a failure was 116 hours—close to five days.
qas: question: zh_tw: 116 小時大概是多少天？
answers: en: text: five

context: en: In March 1948 the converter unit was installed, which made possible programming through the reader from standard IBM cards. The "first production run" of the new coding techniques on the Monte Carlo problem followed in April.  After ENIAC's move to Aberdeen, a register panel for memory was also constructed, but it did not work.  A small master control unit to turn the machine on and off was also added.The programming of the stored program for ENIAC was done by Betty Jennings, Clippinger, Adele Goldstine and others. It was first demonstrated as a stored-program computer in April 1948, running a program by Adele Goldstine for John von Neumann. This modification reduced the speed of ENIAC by a factor of 6 and eliminated the ability of parallel computation, but as it also reduced the reprogramming time to hours instead of days, it was considered well worth the loss of performance. Also analysis had shown that due to differences between the electronic speed of computation and the electromechanical speed of input/output, almost any real-world problem was completely I/O bound, even without making use of the original machine's parallelism. Most computations would still be I/O bound, even after the speed reduction imposed by this modification.
qas: question: zh_tw: 修改消除了什麼能力？
answers: en: text: parallel computation

context: en: Several tubes burned out almost every day, leaving ENIAC nonfunctional about half the time. Special high-reliability tubes were not available until 1948. Most of these failures, however, occurred during the warm-up and cool-down periods, when the tube heaters and cathodes were under the most thermal stress. Engineers reduced ENIAC's tube failures to the more acceptable rate of one tube every two days. According to an interview in 1989 with Eckert, "We had a tube fail about every two days and we could locate the problem within 15 minutes."
qas: question: zh_tw: ENIAC 的管子多久停工一次？
answers: en: text: every two days

question: zh_tw: 兩天內有多少管更具可持續性？
answers: en: text: one