{"id":121,"date":"2026-09-12T10:05:21","date_gmt":"2026-09-12T10:05:21","guid":{"rendered":"https:\/\/darrenizzard.com\/?p=121"},"modified":"2026-09-12T10:05:59","modified_gmt":"2026-09-12T10:05:59","slug":"beech-bbc-micro-emulator-0-5","status":"publish","type":"post","link":"https:\/\/darrenizzard.com\/index.php\/2026\/09\/12\/beech-bbc-micro-emulator-0-5\/","title":{"rendered":"Beech (BBC Micro Emulator ) 0.5"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">Some major fixes to the sound output.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>ENVELOPE decay and SOUND volumes use a 2dB step instead of a linear ramp, matching the real SN76489 chip.<\/li>\n\n\n\n<li>Music 500\/5000 should be much improved*, thanks to a discussion on stardot.org.uk which hoglet messaged me about literally years ago. Thanks for that and sorry for the extremely long wait until I dealt with it.<\/li>\n<\/ul>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><tbody><tr><td>Windows 32-bit binary<\/td><td><a href=\"https:\/\/darrenizzard.com\/wp-content\/uploads\/2026\/09\/Beech-x86.zip\">Beech-x86.zip<\/a><\/td><\/tr><tr><td>Windows 64-bit binary<\/td><td><a href=\"https:\/\/darrenizzard.com\/wp-content\/uploads\/2026\/09\/Beech-x64.zip\">Beech-x64.zip<\/a><\/td><\/tr><tr><td>Source<\/td><td><a href=\"https:\/\/darrenizzard.com\/wp-content\/uploads\/2026\/09\/Beech-src.zip\">Beech-src.zip<\/a><\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Usage, requirements, and other info at the original post: <a href=\"https:\/\/darrenizzard.com\/index.php\/2015\/08\/24\/beech-a-bbc-micro-emulator\/\">https:\/\/darrenizzard.com\/index.php\/2015\/08\/24\/beech-a-bbc-micro-emulator\/<\/a><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><em>* I&#8217;m aware that the Music 500\/5000 output is still missing the four-pole filter at the output stage. My reading of the schematic doesn&#8217;t match how recordings sound, and while I know the b-em emulator has two filters built-in, I didn&#8217;t want to reuse those coefficients without  knowing where they came from (or indeed without permission!).<\/em><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><em>I don&#8217;t have a real device to check but if anyone could send me a good-quality photo of the board, it&#8217;d be much appreciated. The bits I&#8217;d like to see is are the four capacitors around each TL072, clear enough to read their markings. That&#8217;s C21-C24 on the right channel, C15-C18 on the left. Also the issue number silk-screened on the PCB.<\/em><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Some major fixes to the sound output. Windows 32-bit binary Beech-x86.zip Windows 64-bit binary Beech-x64.zip Source Beech-src.zip Usage, requirements, and other info at the original post: https:\/\/darrenizzard.com\/index.php\/2015\/08\/24\/beech-a-bbc-micro-emulator\/ * I&#8217;m aware that the Music 500\/5000 output is still missing the four-pole filter at the output stage. My reading of the schematic doesn&#8217;t match how recordings sound, [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4,2,3],"tags":[7,8,5,9,6],"class_list":["post-121","post","type-post","status-publish","format-standard","hentry","category-bbc-micro","category-emulators","category-retro-computing","tag-8bit","tag-bbcmicro","tag-beech","tag-emulator","tag-retro"],"_links":{"self":[{"href":"https:\/\/darrenizzard.com\/index.php\/wp-json\/wp\/v2\/posts\/121","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/darrenizzard.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/darrenizzard.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/darrenizzard.com\/index.php\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/darrenizzard.com\/index.php\/wp-json\/wp\/v2\/comments?post=121"}],"version-history":[{"count":1,"href":"https:\/\/darrenizzard.com\/index.php\/wp-json\/wp\/v2\/posts\/121\/revisions"}],"predecessor-version":[{"id":125,"href":"https:\/\/darrenizzard.com\/index.php\/wp-json\/wp\/v2\/posts\/121\/revisions\/125"}],"wp:attachment":[{"href":"https:\/\/darrenizzard.com\/index.php\/wp-json\/wp\/v2\/media?parent=121"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/darrenizzard.com\/index.php\/wp-json\/wp\/v2\/categories?post=121"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/darrenizzard.com\/index.php\/wp-json\/wp\/v2\/tags?post=121"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}