{"id":3737,"date":"2017-04-13T06:12:29","date_gmt":"2017-04-13T04:12:29","guid":{"rendered":"http:\/\/www.retro.co.za\/blog\/?p=3737"},"modified":"2017-04-13T12:43:31","modified_gmt":"2017-04-13T10:43:31","slug":"early-in-line-memory-modules","status":"publish","type":"post","link":"http:\/\/www.retro.co.za\/blog\/?p=3737","title":{"rendered":"Early in-line memory modules"},"content":{"rendered":"<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-3739\" src=\"http:\/\/www.retro.co.za\/blog\/wp-content\/uploads\/2017\/04\/IMG_9817r.jpg\" alt=\"IMG_9817r\" width=\"640\" height=\"340\" srcset=\"http:\/\/www.retro.co.za\/blog\/wp-content\/uploads\/2017\/04\/IMG_9817r.jpg 640w, http:\/\/www.retro.co.za\/blog\/wp-content\/uploads\/2017\/04\/IMG_9817r-300x159.jpg 300w\" sizes=\"auto, (max-width: 640px) 100vw, 640px\" \/><\/p>\n<p>Predecessor of the <a href=\"https:\/\/en.wikipedia.org\/wiki\/SIMM\">SIMM<\/a>?<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-3738\" src=\"http:\/\/www.retro.co.za\/blog\/wp-content\/uploads\/2017\/04\/IMG_9816r.jpg\" alt=\"IMG_9816r\" width=\"640\" height=\"894\" srcset=\"http:\/\/www.retro.co.za\/blog\/wp-content\/uploads\/2017\/04\/IMG_9816r.jpg 640w, http:\/\/www.retro.co.za\/blog\/wp-content\/uploads\/2017\/04\/IMG_9816r-215x300.jpg 215w\" sizes=\"auto, (max-width: 640px) 100vw, 640px\" \/><\/p>\n<p>This comes from a piece of medical equipment made by the <em>other<\/em> S&amp;W, Simonsen &amp; Weel, Denmark, circa 1979.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-3740\" src=\"http:\/\/www.retro.co.za\/blog\/wp-content\/uploads\/2017\/04\/IMG_9769r.jpg\" alt=\"IMG_9769r\" width=\"800\" height=\"105\" srcset=\"http:\/\/www.retro.co.za\/blog\/wp-content\/uploads\/2017\/04\/IMG_9769r.jpg 800w, http:\/\/www.retro.co.za\/blog\/wp-content\/uploads\/2017\/04\/IMG_9769r-300x39.jpg 300w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><\/p>\n<p>Each module has 8 x <a href=\"https:\/\/4donline.ihs.com\/images\/VipMasterIC\/IC\/AMDI\/AMDID077\/AMDID077-5-13.pdf?hkey=EF798316E3902B6ED9A73243A3159BB0\">AM2808PC<\/a>\u00a01024-bit dynamic shift registers, driven by a <a href=\"http:\/\/html.alldatasheet.com\/html-pdf\/127791\/NSC\/DS0025CN\/55\/1\/DS0025CN.html\">DS0025CN<\/a> two-phase clock driver. That&#8217;s one kilobyte of storage per module, and you have to keep on clocking the data around the ring otherwise the capacitors making up the memory discharge and forget.<\/p>\n<p>It&#8217;s a lot simpler than a <a href=\"http:\/\/forums.xkcd.com\/viewtopic.php?t=15611\">mercury delay line memory<\/a>, but functionally it&#8217;s not that much different.<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Predecessor of the SIMM? This comes from a piece of medical equipment made by the other S&amp;W, Simonsen &amp; Weel, Denmark, circa 1979. Each module has 8 x AM2808PC\u00a01024-bit dynamic shift registers, driven by a DS0025CN two-phase clock driver. That&#8217;s one kilobyte of storage per module, and you have to keep on clocking the data around the ring otherwise the capacitors making up the memory discharge and forget. It&#8217;s a lot simpler than a mercury delay line memory, but functionally it&#8217;s not that much different. &nbsp; &nbsp; &nbsp;<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[66,83],"tags":[],"class_list":["post-3737","post","type-post","status-publish","format-standard","hentry","category-computers","category-get-off-my-lawn"],"_links":{"self":[{"href":"http:\/\/www.retro.co.za\/blog\/index.php?rest_route=\/wp\/v2\/posts\/3737","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.retro.co.za\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.retro.co.za\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.retro.co.za\/blog\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"http:\/\/www.retro.co.za\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=3737"}],"version-history":[{"count":1,"href":"http:\/\/www.retro.co.za\/blog\/index.php?rest_route=\/wp\/v2\/posts\/3737\/revisions"}],"predecessor-version":[{"id":3741,"href":"http:\/\/www.retro.co.za\/blog\/index.php?rest_route=\/wp\/v2\/posts\/3737\/revisions\/3741"}],"wp:attachment":[{"href":"http:\/\/www.retro.co.za\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3737"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.retro.co.za\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3737"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.retro.co.za\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3737"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}