{"id":52,"date":"2013-11-26T21:24:13","date_gmt":"2013-11-26T21:24:13","guid":{"rendered":"http:\/\/www.randomorbit.co.uk\/wordpress\/?p=52"},"modified":"2015-09-05T21:30:27","modified_gmt":"2015-09-05T20:30:27","slug":"380-entering-a-hiatus","status":"publish","type":"post","link":"https:\/\/www.randomorbit.co.uk\/?p=52","title":{"rendered":"380Z entering a hiatus…"},"content":{"rendered":"

The progress has been a bit slow on the 380Z<\/a> front at the moment.<\/p>\n

As you may have read<\/a>, It displays nonsense on the screen and doesn’t do much else. I wondered if this was just a fault with the display controller card or more. At startup the machine is supposed to display a boot prompt and wait for a key press. however, I don’t have a keyboard. The keyboard interface is a simple parallel port with 8 bits for the decoded key code and a strobe to say that the data is ready. To try and make some progress I made a simple one key keyboard built into a 15 way connector.<\/p>\n

All it does is permanently tie the lines needed to send a ‘b’ and then it has a push button on the strobe line. I push the button and the 380Z thinks I’ve pressed a ‘b’.<\/p>\n

 <\/p>\n

This didn’t change anything and so I think the problem is more with the logic board.<\/p>\n

 <\/p>\n

ROMS?<\/h2>\n

It has been suggested that the ROMS (EPROMS) might have lost their memory. I think their original life expectancy was only about 10 years and we’re way past that now. I would like to read them and compare them with the image files<\/a> that I have. The chips used are TMS-2716, 2kx x8-bit EPROM from Texas Instruments. Their power requirements are the same as the 2708s and different to non-TI 2716s. I have been able to borrow an EPROM programmer and I have the needed adapter on order from the USA but unfortunately the seller has had some problems with his supplier and it’s taking longer than I had hoped.<\/p>\n

When it gets here I’ll be on the case.<\/p>\n

 <\/p>\n","protected":false},"excerpt":{"rendered":"

The progress has been a bit slow on the 380Z front at the moment. As you may have read, It displays nonsense on the screen and doesn’t do much else. I wondered if this was just a fault with the display controller card or more. At startup the machine is supposed to display a boot … Continue reading 380Z entering a hiatus…<\/span> →<\/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":[47,44],"tags":[],"class_list":["post-52","post","type-post","status-publish","format-standard","hentry","category-c93-blog-posts","category-c96-rml380z"],"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\/52","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=52"}],"version-history":[{"count":3,"href":"https:\/\/www.randomorbit.co.uk\/index.php?rest_route=\/wp\/v2\/posts\/52\/revisions"}],"predecessor-version":[{"id":72,"href":"https:\/\/www.randomorbit.co.uk\/index.php?rest_route=\/wp\/v2\/posts\/52\/revisions\/72"}],"wp:attachment":[{"href":"https:\/\/www.randomorbit.co.uk\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=52"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.randomorbit.co.uk\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=52"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.randomorbit.co.uk\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=52"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}