{"id":754,"date":"2015-02-15T16:33:37","date_gmt":"2015-02-15T16:33:37","guid":{"rendered":"http:\/\/www.randomorbit.co.uk\/wordpress\/?p=754"},"modified":"2015-02-21T13:48:42","modified_gmt":"2015-02-21T13:48:42","slug":"commode-4032","status":"publish","type":"post","link":"https:\/\/www.randomorbit.co.uk\/?p=754","title":{"rendered":"Commodore 4032."},"content":{"rendered":"<p><a href=\"http:\/\/www.randomorbit.co.uk\/wordpress\/wp-content\/uploads\/2015\/02\/Pet4032-StartUp.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignleft size-medium wp-image-757\" src=\"http:\/\/www.randomorbit.co.uk\/wordpress\/wp-content\/uploads\/2015\/02\/Pet4032-StartUp-300x169.jpg\" alt=\"Pet4032-StartUp\" width=\"300\" height=\"169\" srcset=\"https:\/\/www.randomorbit.co.uk\/wordpress\/wp-content\/uploads\/2015\/02\/Pet4032-StartUp-300x169.jpg 300w, https:\/\/www.randomorbit.co.uk\/wordpress\/wp-content\/uploads\/2015\/02\/Pet4032-StartUp-1024x575.jpg 1024w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a>A friend at work, knowing that I was interested in retro computing, arrived one day with this splendid example of a <a href=\"http:\/\/en.wikipedia.org\/wiki\/Commodore_PET#PET_4000_series_.2F_CBM_8000_series\">Commodore 4032.<\/a>. Sadly when I powered it up I only got a &#8220;Bingley beep&#8221; sound but there was at least some signs of life.<\/p>\n<p>I moved around the board with a scope and found the clock looked good, as did the horizontal and vertical video signals.<\/p>\n<p>More searching found that the _INT_ line to the 6502 was low. I reasoned that it should be mostly high. The 6520 PIA controller driving the IEEE port is connected to that line and as I didn&#8217;t need IEEE at the moment I pulled the chip out. Power up and Bingo! now running.<a href=\"http:\/\/www.randomorbit.co.uk\/wordpress\/wp-content\/uploads\/2015\/02\/Pet4032-J7-pin5.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignleft size-medium wp-image-758\" src=\"http:\/\/www.randomorbit.co.uk\/wordpress\/wp-content\/uploads\/2015\/02\/Pet4032-J7-pin5-300x169.jpg\" alt=\"Pet4032-J7-pin5\" width=\"300\" height=\"169\" srcset=\"https:\/\/www.randomorbit.co.uk\/wordpress\/wp-content\/uploads\/2015\/02\/Pet4032-J7-pin5-300x169.jpg 300w, https:\/\/www.randomorbit.co.uk\/wordpress\/wp-content\/uploads\/2015\/02\/Pet4032-J7-pin5-1024x575.jpg 1024w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><\/p>\n<p>&nbsp;<\/p>\n<p>I replaced the 6520 and all is now well.<\/p>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>A friend at work, knowing that I was interested in retro computing, arrived one day with this splendid example of a Commodore 4032.. Sadly when I powered it up I only got a &#8220;Bingley beep&#8221; sound but there was at least some signs of life. I moved around the board with a scope and found &hellip; <a href=\"https:\/\/www.randomorbit.co.uk\/?p=754\" class=\"more-link\">Continue reading <span class=\"screen-reader-text\">Commodore 4032.<\/span> <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_coblocks_attr":"","_coblocks_dimensions":"","_coblocks_responsive_height":"","_coblocks_accordion_ie_support":"","footnotes":""},"categories":[78,77,33],"tags":[],"class_list":["post-754","post","type-post","status-publish","format-standard","hentry","category-78","category-commodore","category-c84-retro-tech"],"featured_image_src":null,"author_info":{"display_name":"andy","author_link":"https:\/\/www.randomorbit.co.uk\/?author=1"},"_links":{"self":[{"href":"https:\/\/www.randomorbit.co.uk\/index.php?rest_route=\/wp\/v2\/posts\/754","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.randomorbit.co.uk\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.randomorbit.co.uk\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.randomorbit.co.uk\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.randomorbit.co.uk\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=754"}],"version-history":[{"count":4,"href":"https:\/\/www.randomorbit.co.uk\/index.php?rest_route=\/wp\/v2\/posts\/754\/revisions"}],"predecessor-version":[{"id":761,"href":"https:\/\/www.randomorbit.co.uk\/index.php?rest_route=\/wp\/v2\/posts\/754\/revisions\/761"}],"wp:attachment":[{"href":"https:\/\/www.randomorbit.co.uk\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=754"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.randomorbit.co.uk\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=754"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.randomorbit.co.uk\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=754"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}