English: Operating en:IBM 1620 computer (Model 1 Level H) at the Computer History Museum. I took this photo and edited it.
This computer was restored by a team of volunteers over a two year period after having sat idle for over 15 years. This machine was originally built in about 1964 (based on part datecodes). The only severe problem encountered was that the en:core memory is completely inoperative due to corrosion (caused by incorrect solder flux when the machine was built) and had to be replaced with SRAM chips. As an illustration of the change in price of computers; the original core memory (60,000 decimal digits) cost about $90,000 in 1964 (this would be over $500,000 in 2000 dollars due to inflation), we replaced this with 1MByte of SRAM totaling $40 and used only about 4.25% of this memory (the rest is unused due to the decimal based addressing of the 1620 and only 6 bits of each byte are used due to the decimal data format of the 1620). In other words, $90,000 of core was effectively replaced by less than $2 of SRAM storage (with the remaining $38 dumped as waste)... memory is almost free now. Less than a dozen transistors were replaced (of the about 5,000 in the computer) to repair the electronics; except for one, all were original IBM transistors from the period.
GNU 자유 문서 사용 허가서 1.2판 또는 자유 소프트웨어 재단에서 발행한 이후 판의 규정에 따라 본 문서를 복제하거나 개작 및 배포할 수 있습니다. 본 문서에는 변경 불가 부분이 없으며, 앞 표지 구절과 뒷 표지 구절도 없습니다. 본 사용 허가서의 전체 내용은 GNU 자유 문서 사용 허가서 부분에 포함되어 있습니다.http://www.gnu.org/copyleft/fdl.htmlGFDLGNU Free Documentation Licensetruetrue
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이 라이선스 틀은 GFDL 라이선스 변경의 일부로 이 파일에 추가되었습니다.http://creativecommons.org/licenses/by-sa/3.0/CC BY-SA 3.0Creative Commons Attribution-Share Alike 3.0truetrue
기존 올리기 기록
The original description page was here. All following user names refer to en.wikipedia.
2006-06-22 16:52 Crazytales 375×246×8 (46134 bytes) Reverted to earlier revision
2006-06-22 16:52 Crazytales 350×230×8 (15905 bytes) Reverted to earlier revision
2003-10-18 22:00 RTC 375×246×8 (46134 bytes) Better quality version of the picture I uploaded before.
2003-10-11 20:04 RTC 350×230×8 (15905 bytes) Operating [[IBM 1620]] computer (Model 1 Level G) at the Computer History Museum. I took this photo and edited it.
{{BotMoveToCommons|en.wikipedia}} {{Information |Description={{en|Operating en:IBM 1620 computer (Model 1 Level H) at the Computer History Museum. I took this photo and edited it. This computer was restored by a team of volunteers over a two year p