Editing IBM 7030 Stretch (section)

==Hardware implementation==
[[File:IBM 7030 Stretch circuit board.jpg|right|thumbnail|A circuit board from the IBM 7030, in the [[Bradbury Science Museum]], [[Los Alamos, New Mexico]].]]
The 7030 CPU uses [[emitter-coupled logic]] (originally called ''current-steering logic'')<ref name="Rymaszewski">{{cite journal |author-first=E. J. |author-last=Rymaszewski |year=1981 |title=Semiconductor Logic Technology in IBM |journal=IBM Journal of Research and Development |volume=25 |issue=5 |pages=607–608 |issn=0018-8646 |doi=10.1147/rd.255.0603 |display-authors=etal}}</ref> on 18 types of [[Standard Modular System]] cards. It uses 4,025 double cards (as shown) and 18,747 single cards, holding 169,100 transistors, requiring a total of 21&nbsp;kW power.<ref name=Bloch1959>{{cite conference|url=http://www.bitsavers.org/pdf/ibm/7030/Bloch_EngrDesOfStretch_1959.pdf|title=The Engineering Design of the Stretch Computer|author=Erich Bloch|author-link=Erich Bloch|conference=Eastern Joint Computer Conference|year=1959}}</ref>{{rp|54}} It uses high-speed NPN and PNP germanium [[drift transistor]]s, with cut-off frequency over 100&nbsp;MHz, and using ~50&nbsp;mW each.<ref name=Bloch1959/>{{rp|57}} Some ''third level'' circuits use a third voltage level. Each logic level has a delay of about 20 ns. To gain speed in critical areas [[emitter-coupled logic|emitter-follower logic]] is used to reduce the delay to about 10 ns.<ref name="Bloch1959"/>{{rp|55}}

It uses the same core memory as the [[IBM 7090]].<ref name="Bloch1959"/>{{rp|58}}