With the console typewriter working, and the ability to load core images, I was now ready to try and run some diagnostics. The first issue I ran into was that the main diagnostics, CU01, was initialized for 80K of core. That the core image file was larger wasn’t an issue: the Windows based support program knows to only send the first 40K. However, there was a flag denoting machine size that needed to be “patched” — which I did using my emulator, and then saved as a new core image.<\/p>\n\n\n\n
Loading the diagnostic, it typed out its identifier, but then quickly errored out with an Assembly Channel error on a Subtract instruction where the destination B-field was initially positive, but turned negative during the subtraction. This was not the first place I expected to see an issue – figured it would more likely relate to some trigger or other. But nope, this was a simple issue in the Assembly Channel.<\/p>\n\n\n\n
The problem arose because the ALD diagrams I have are mostly for an IBM 1410 with the Accelerator special feature, however, most of the ALD diagrams for the Assembly channel proper (ALD 15.50.xx.1) are for the non-accelerated version whereas the Assembly channel controls (ALD 15.49.xx.1) are for the accelerated version. There were several signals that ended up either not being used, or having no source as a result:<\/p>\n\n\n\n
These all relate to cases where the B field ends up with a sign other than its original sign. I suspect that the idea was that these signals provided earlier gating to the assembly channel rather than just deriving them from the adder with additional gate delays.<\/p>\n\n\n\n
After fixing the Subtract issues which involved just the “B” bit on page 15.50.06.1, (going from positive to negative) I immediately ran into the same issue on the first pass of the diagnostic during the same test, changing from negative to a positive result. Fixing this involved pages 15.50.05.1 (mostly). As a result the pages for the Assembly channel have some gates who’s note at the top is “FUDGED”. \ud83d\ude09<\/p>\n\n\n\n
With that, so long as I didn’t enable I\/O overlap and Priority Alert (interrupts) during the test, CU01 completed successfully! Frankly this was something of a surprise: It tests most of the instructions and ways of moving data and they all just worked. <\/p>\n\n\n\n
Also, the run time of about 3.75 minutes matches very well with the information in the diagnostic listing for a 1410 with the Accelerated logic feature.<\/p>\n\n\n\n
So then, I ran it again, but with overlapped I\/O and priority features turned on in the diagnostic. It ran fine for about a minute, but then failed during overlapped execution of a multiply instruction. More on this during the next installment.<\/p>\n\n\n\n
<\/p>\n","protected":false},"excerpt":{"rendered":"
With the console typewriter working, and the ability to load core images, I was now ready to try and run some diagnostics. The first issue I ran into was that the main diagnostics, CU01, was initialized for 80K of core. That the core image file was larger wasn’t an issue: the Windows based support program … Continue reading “IBM 1410 FPGA: Diagnostics!!!”<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5,9,15],"tags":[16],"post_folder":[],"class_list":["post-1581","post","type-post","status-publish","format-standard","hentry","category-computers","category-hardware","category-ibm1410","tag-ibm1410-2"],"_links":{"self":[{"href":"https:\/\/www.computercollection.net\/index.php\/wp-json\/wp\/v2\/posts\/1581","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.computercollection.net\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.computercollection.net\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.computercollection.net\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.computercollection.net\/index.php\/wp-json\/wp\/v2\/comments?post=1581"}],"version-history":[{"count":4,"href":"https:\/\/www.computercollection.net\/index.php\/wp-json\/wp\/v2\/posts\/1581\/revisions"}],"predecessor-version":[{"id":1586,"href":"https:\/\/www.computercollection.net\/index.php\/wp-json\/wp\/v2\/posts\/1581\/revisions\/1586"}],"wp:attachment":[{"href":"https:\/\/www.computercollection.net\/index.php\/wp-json\/wp\/v2\/media?parent=1581"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.computercollection.net\/index.php\/wp-json\/wp\/v2\/categories?post=1581"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.computercollection.net\/index.php\/wp-json\/wp\/v2\/tags?post=1581"},{"taxonomy":"post_folder","embeddable":true,"href":"https:\/\/www.computercollection.net\/index.php\/wp-json\/wp\/v2\/post_folder?post=1581"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}