{"id":945,"date":"2022-11-19T06:44:30","date_gmt":"2022-11-19T06:44:30","guid":{"rendered":"http:\/\/tlindner.macmess.org\/?p=945"},"modified":"2022-11-19T06:47:59","modified_gmt":"2022-11-19T06:47:59","slug":"6809-exchange-and-transfer-opcodes","status":"publish","type":"post","link":"http:\/\/tlindner.macmess.org\/?p=945","title":{"rendered":"6809 Exchange and Transfer Opcodes"},"content":{"rendered":"<p>It was recently brought to my attention that <a href=\"https:\/\/colorcomputerarchive.com\/repo\/Documents\/Books\/Motorola%206809%20and%20Hitachi%206309%20Programming%20Reference%20%28Darren%20Atkinson%29.pdf\" title=\"Motorola 6809 and Hitachi 6309 Programming Reference\">Darren Atkinson<\/a> has a really good summary of the invalid register exchange and transfer opcodes in the 6809.<\/p>\n<p>So good, that I should use the information to make MAME&#8217;s 6809 better match real hardware.<\/p>\n<p>That will be a future post. In the mean time, I wrote a little program to exercise all of the invalid combinations and print results to the CoCo&#8217;s screen memory. This way I can, eventually, verify the implementation.<\/p>\n<p>The software package is here: <a href=\"http:\/\/tlindner.macmess.org\/wp-content\/uploads\/2022\/11\/Test-Exg-TFR.zip\">Test-Exg-TFR.zip<\/a><\/p>\n<p>Here is a screen shot from a real CoCo 2B with a 6809 running my program:\n<a href=\"http:\/\/tlindner.macmess.org\/wp-content\/uploads\/2022\/11\/REAL-coco2b.png\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/tlindner.macmess.org\/wp-content\/uploads\/2022\/11\/REAL-coco2b.png\" alt=\"REAL coco2b\" width=\"906\" height=\"512\" class=\"alignnone size-full wp-image-946\" \/><\/a><\/p>\n<p>And here is a screen shot form a real CoCo 3 with a 6309 running the same program:\n<a href=\"http:\/\/tlindner.macmess.org\/wp-content\/uploads\/2022\/11\/REAL-CoCo3h.png\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/tlindner.macmess.org\/wp-content\/uploads\/2022\/11\/REAL-CoCo3h.png\" alt=\"REAL CoCo3h\" width=\"956\" height=\"720\" class=\"alignnone size-full wp-image-947\" \/><\/a><\/p>\n<p>By &#8220;invalid&#8221;, I mean the combinations of registers that Motorola didn&#8217;t document. Combinations like specifying different width registers when exchanging or transferring. Or the use of the register bit patterns not defined by Motorola.<\/p>","protected":false},"excerpt":{"rendered":"<p>It was recently brought to my attention that Darren Atkinson has a really good summary of the invalid register exchange and transfer opcodes in the 6809. So good, that I should use the information to make MAME&#8217;s 6809 better match &hellip; <a href=\"http:\/\/tlindner.macmess.org\/?p=945\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-945","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"jetpack_featured_media_url":"","_links":{"self":[{"href":"http:\/\/tlindner.macmess.org\/index.php?rest_route=\/wp\/v2\/posts\/945","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/tlindner.macmess.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/tlindner.macmess.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/tlindner.macmess.org\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/tlindner.macmess.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=945"}],"version-history":[{"count":8,"href":"http:\/\/tlindner.macmess.org\/index.php?rest_route=\/wp\/v2\/posts\/945\/revisions"}],"predecessor-version":[{"id":956,"href":"http:\/\/tlindner.macmess.org\/index.php?rest_route=\/wp\/v2\/posts\/945\/revisions\/956"}],"wp:attachment":[{"href":"http:\/\/tlindner.macmess.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=945"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/tlindner.macmess.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=945"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/tlindner.macmess.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=945"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}