{"id":579,"date":"2013-06-26T21:52:07","date_gmt":"2013-06-26T21:52:07","guid":{"rendered":"http:\/\/retroramblings.net\/?p=579"},"modified":"2013-07-06T11:19:06","modified_gmt":"2013-07-06T11:19:06","slug":"from-the-what-are-you-nuts-department","status":"publish","type":"post","link":"https:\/\/retroramblings.net\/?p=579","title":{"rendered":"From the “What, are you nuts?” department!"},"content":{"rendered":"

I have an Amiga with a ZPU processor!<\/p>\n

So what possessed me to create such a perverse combination? Quite simply that it synthesizes in about a third of the time that a TG68-based equivalent would, which speeds up the development cycle significantly while I’m bug hunting.<\/p>\n

(I will admit there’s an element of “because I can” there, too!)<\/p>\n

\"ZPUChipRAMTest\"<\/a><\/p>\n

This not-very-exciting screenshot shows a simple program running on the ZPU, and testing the reliability of reads and writes to Chip RAM through the Vampire500.\u00a0 The program simply sets up a 2-colour high-res screen, clears the framebuffer, and then repeatedly adds 1 to each longword within the framebuffer.\u00a0 Any glitches in either reading or writing would thus be cumulative, so if I can leave the program running for a while and if the pattern on screen remains in nice neat columns (which it does), I can be sure that no glitches have occurred. (Or that any errors are perfectly consistent!)<\/p>\n

Of course, a ZPU-based Amiga is of no practical use whatsoever, besides assisting in debugging the Vampire500 – but I find myself idly wondering how practical it would be to use a more modern CPU – such as, perhaps, the OR1200 – and then emulate the 68000 in firmware?<\/p>\n

Anyhow, pipe-dreams aside, the next task will be to take a checksum of the Kickstart ROM, since ROM reads are the only kind I haven’t yet tested.<\/p>\n","protected":false},"excerpt":{"rendered":"

I have an Amiga with a ZPU processor! So what possessed me to create such a perverse combination? Quite simply that it synthesizes in about a third of the time that a TG68-based equivalent would, which speeds up the development … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3,4],"tags":[],"class_list":["post-579","post","type-post","status-publish","format-standard","hentry","category-amiga","category-fpga"],"_links":{"self":[{"href":"https:\/\/retroramblings.net\/index.php?rest_route=\/wp\/v2\/posts\/579","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/retroramblings.net\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/retroramblings.net\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/retroramblings.net\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/retroramblings.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=579"}],"version-history":[{"count":7,"href":"https:\/\/retroramblings.net\/index.php?rest_route=\/wp\/v2\/posts\/579\/revisions"}],"predecessor-version":[{"id":586,"href":"https:\/\/retroramblings.net\/index.php?rest_route=\/wp\/v2\/posts\/579\/revisions\/586"}],"wp:attachment":[{"href":"https:\/\/retroramblings.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=579"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/retroramblings.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=579"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/retroramblings.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=579"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}