{"id":14256,"date":"2026-06-21T12:57:15","date_gmt":"2026-06-21T12:57:15","guid":{"rendered":"https:\/\/www.fambach.net\/?p=14256"},"modified":"2026-06-21T12:57:17","modified_gmt":"2026-06-21T12:57:17","slug":"retro_pojekt-isa-8bit-backplane","status":"publish","type":"post","link":"https:\/\/www.fambach.net\/en\/retro_pojekt-isa-8bit-backplane\/","title":{"rendered":"Retro Project - ISA 8-Bit Backplane"},"content":{"rendered":"<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_73 ez-toc-wrap-left counter-hierarchy ez-toc-counter ez-toc-grey ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Contents\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewbox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewbox=\"0 0 24 24\" version=\"1.2\" baseprofile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1' ><li class='ez-toc-page-1 ez-toc-heading-level-1'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/www.fambach.net\/en\/retro_pojekt-template-3\/#Link_zum_Projekt\" title=\"Link to the project\">Link to the project<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-1'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/www.fambach.net\/en\/retro_pojekt-template-3\/#Ansichten\" title=\"Views\">Views<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-1'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/www.fambach.net\/en\/retro_pojekt-template-3\/#Fakten\" title=\"Facts\">Facts<\/a><ul class='ez-toc-list-level-2' ><li class='ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/www.fambach.net\/en\/retro_pojekt-template-3\/#Schaltplane\" title=\"Circuit diagrams\">Circuit diagrams<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/www.fambach.net\/en\/retro_pojekt-template-3\/#Dokumentation\" title=\"Documentation\">Documentation<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-1'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/www.fambach.net\/en\/retro_pojekt-template-3\/#Zusammenbau\" title=\"Assembly\">Assembly<\/a><ul class='ez-toc-list-level-2' ><li class='ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/www.fambach.net\/en\/retro_pojekt-template-3\/#Platine\" title=\"Record\">Record<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/www.fambach.net\/en\/retro_pojekt-template-3\/#Bauteile\" title=\"Components\">Components<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/www.fambach.net\/en\/retro_pojekt-template-3\/#Aufbau\" title=\"Structure\">Structure<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"https:\/\/www.fambach.net\/en\/retro_pojekt-template-3\/#Varianten\" title=\"Variations\">Variations<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-11\" href=\"https:\/\/www.fambach.net\/en\/retro_pojekt-template-3\/#Reihenfolge\" title=\"Order\">Order<\/a><\/li><\/ul><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-1'><a class=\"ez-toc-link ez-toc-heading-12\" href=\"https:\/\/www.fambach.net\/en\/retro_pojekt-template-3\/#Inbetriebnahme\" title=\"Commissioning\">Commissioning<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-1'><a class=\"ez-toc-link ez-toc-heading-13\" href=\"https:\/\/www.fambach.net\/en\/retro_pojekt-template-3\/#Sonstiges\" title=\"Miscellaneous\">Miscellaneous<\/a><ul class='ez-toc-list-level-2' ><li class='ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-14\" href=\"https:\/\/www.fambach.net\/en\/retro_pojekt-template-3\/#Generelle_Tips\" title=\"General Tips\">General Tips<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-15\" href=\"https:\/\/www.fambach.net\/en\/retro_pojekt-template-3\/#Lotstellen\" title=\"Soldering points\">Soldering points<\/a><\/li><\/ul><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-1'><a class=\"ez-toc-link ez-toc-heading-16\" href=\"https:\/\/www.fambach.net\/en\/retro_pojekt-template-3\/#Probleme\" title=\"Problems\">Problems<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-1'><a class=\"ez-toc-link ez-toc-heading-17\" href=\"https:\/\/www.fambach.net\/en\/retro_pojekt-template-3\/#Fazit\" title=\"Conclusion\">Conclusion<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-1'><a class=\"ez-toc-link ez-toc-heading-18\" href=\"https:\/\/www.fambach.net\/en\/retro_pojekt-template-3\/#Verwandte_Beitrage\" title=\"Related Posts\">Related Posts<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-1'><a class=\"ez-toc-link ez-toc-heading-19\" href=\"https:\/\/www.fambach.net\/en\/retro_pojekt-template-3\/#Quellen\" title=\"Sources\">Sources<\/a><ul class='ez-toc-list-level-2' ><li class='ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-20\" href=\"https:\/\/www.fambach.net\/en\/retro_pojekt-template-3\/#Zum_Projekt\" title=\"To the project\">To the project<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-21\" href=\"https:\/\/www.fambach.net\/en\/retro_pojekt-template-3\/#Retro_Seiten\" title=\"Retro pages\">Retro pages<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-22\" href=\"https:\/\/www.fambach.net\/en\/retro_pojekt-template-3\/#Retro_Foren\" title=\"Retro Forensics\">Retro Forensics<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-23\" href=\"https:\/\/www.fambach.net\/en\/retro_pojekt-template-3\/#Retro_Shops\" title=\"Retro Shops\">Retro Shops<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-1'><a class=\"ez-toc-link ez-toc-heading-24\" href=\"https:\/\/www.fambach.net\/en\/retro_pojekt-template-3\/#Logbuch\" title=\"Logbook\">Logbook<\/a><\/li><\/ul><\/nav><\/div>\n\n<p>Here comes the circuit board, the one that all <a href=\"https:\/\/github.com\/skiselev\">Sergey Kiselev<\/a> Projects connect. The backplane consists of 7x 8-bit ISA slots, an ATX connector, two LEDs and a power button. Other than that, it doesn't have much more to offer apart from forming a real 8088 PC from all the 8-bit ISA cards.<\/p>\n\n\n\n<h1 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Link_zum_Projekt\"><\/span>Link to the project<span class=\"ez-toc-section-end\"><\/span><\/h1>\n\n\n\n<p><a href=\"https:\/\/github.com\/skiselev\/isa8_backplane\">Link to the project<\/a><\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Series contributions<\/h2>\n\n\n\n<p><a href=\"https:\/\/www.fambach.net\/en\/?p=14252\">ISA 8-bit 8088 Board<\/a> \u2013 The main processor board with 8088 or V20<\/p>\n\n\n\n<p><a href=\"https:\/\/www.fambach.net\/en\/?p=14256\">ISA 8-bit Backplane<\/a> \u2013 Motherboard with ISA slots for the built ISA cards<\/p>\n\n\n\n<p><a href=\"https:\/\/www.fambach.net\/en\/?p=14259\">ISA 8-Bit Super VGA Card<\/a> \u2013 Card based on Trident TVGA9000i chip<\/p>\n\n\n\n<p><a href=\"https:\/\/www.fambach.net\/en\/retro_pojekt-8bit-isa-ethernet-card-isa8_eth\/\">ISA 8-bit Ethernet Card<\/a> \u2013 Modern network card based on the Realtek 8019 chip<\/p>\n\n\n\n<p><\/p>\n\n\n\n<h1 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Ansichten\"><\/span>Views<span class=\"ez-toc-section-end\"><\/span><\/h1>\n\n\n\n<figure class=\"wp-block-gallery has-nested-images columns-1 is-cropped wp-block-gallery-1 is-layout-flex wp-block-gallery-is-layout-flex\">\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"2890\" height=\"1816\" data-id=\"15837\" src=\"https:\/\/www.fambach.net\/wp-content\/uploads\/20260621_111028.jpg\" alt=\"ISA Backplane - Perspektivisch\" class=\"wp-image-15837\"\/><figcaption class=\"wp-element-caption\">ISA Backplane \u2013 Future Outlook<\/figcaption><\/figure>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"2599\" height=\"2048\" data-id=\"15835\" src=\"https:\/\/www.fambach.net\/wp-content\/uploads\/20260621_110944-1.jpg\" alt=\"ISA Backplane - Vorderseite\" class=\"wp-image-15835\"\/><figcaption class=\"wp-element-caption\">ISA Backplane \u2013 Front View<\/figcaption><\/figure>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"2831\" height=\"2084\" data-id=\"15836\" src=\"https:\/\/www.fambach.net\/wp-content\/uploads\/20260621_110956-1.jpg\" alt=\"ISA Backplane - R\u00fcckseite\" class=\"wp-image-15836\"\/><figcaption class=\"wp-element-caption\">ISA Backplane \u2013 Rear<\/figcaption><\/figure>\n<\/figure>\n\n\n\n<h1 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Fakten\"><\/span>Facts<span class=\"ez-toc-section-end\"><\/span><\/h1>\n\n\n\n<ul>\n<li>7x 8-bit ISA slots<\/li>\n\n\n\n<li>Power LED \/ Activity LED<\/li>\n\n\n\n<li>Power button<\/li>\n\n\n\n<li>20-pin ATX connector<\/li>\n\n\n\n<li>Pin header for power LED and button<\/li>\n\n\n\n<li>-5V voltage regulator to generate -5V from ATX power supply's -12V<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Schaltplane\"><\/span>Circuit diagrams<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<div data-wp-interactive=\"core\/file\" class=\"wp-block-file\"><object data-wp-bind--hidden=\"!state.hasPdfPreview\"  class=\"wp-block-file__embed\" data=\"https:\/\/www.fambach.net\/wp-content\/uploads\/ISA8_Backplane-Schematic-1.0.pdf\" type=\"application\/pdf\" style=\"width:100%;height:600px\" aria-label=\"Embed of ISA8_Backplane-Schematic-1.0.\"><\/object><a id=\"wp-block-file--media-1d640cf1-21db-4b3a-b123-e7514d1a3861\" href=\"https:\/\/www.fambach.net\/wp-content\/uploads\/ISA8_Backplane-Schematic-1.0.pdf\">ISA8_Backplane-Schematic-1.0<\/a><a href=\"https:\/\/www.fambach.net\/wp-content\/uploads\/ISA8_Backplane-Schematic-1.0.pdf\" class=\"wp-block-file__button wp-element-button\" download aria-describedby=\"wp-block-file--media-1d640cf1-21db-4b3a-b123-e7514d1a3861\">Download<\/a><\/div>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Dokumentation\"><\/span>Documentation<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>No additional documentation is available, all information can be found on GitHub. <a href=\"https:\/\/github.com\/skiselev\/isa8_backplane\">Link to the project<\/a>.<\/p>\n\n\n\n<h1 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Zusammenbau\"><\/span>Assembly<span class=\"ez-toc-section-end\"><\/span><\/h1>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Platine\"><\/span>Record<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<figure class=\"wp-block-table is-style-stripes\"><table><thead><tr><th>Description<\/th><th>Worth<\/th><\/tr><\/thead><tbody><tr><td>Gerber available <\/td><td>Yes<\/td><\/tr><tr><td>Gerber file<\/td><td><a href=\"https:\/\/github.com\/skiselev\/isa8_backplane\/tree\/master\/gerber\">Link<\/a><\/td><\/tr><tr><td>Ordered where<\/td><td>JLCPCB<\/td><\/tr><tr><td>Piece<\/td><td>5<\/td><\/tr><tr><td>Price including tax and delivery<\/td><td>25\u20ac<\/td><\/tr><tr><td>Special features<\/td><td>Leedfree, Blue<\/td><\/tr><\/tbody><\/table><figcaption class=\"wp-element-caption\">PCB order data<\/figcaption><\/figure>\n\n\n\n<p>Here are the Gerber files saved. Please check the original site for anything newer.<\/p>\n\n\n\n<div class=\"wp-block-file\"><a id=\"wp-block-file--media-a90fa077-77a9-400b-9211-89148cea6255\" href=\"https:\/\/www.fambach.net\/wp-content\/uploads\/isa8Bit_backplane.zip\">isa8Bit_backplane<\/a><a href=\"https:\/\/www.fambach.net\/wp-content\/uploads\/isa8Bit_backplane.zip\" class=\"wp-block-file__button wp-element-button\" download aria-describedby=\"wp-block-file--media-a90fa077-77a9-400b-9211-89148cea6255\">Download<\/a><\/div>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Bauteile\"><\/span>Components<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p><\/p>\n\n\n\n<p>I ordered the components from various retailers. The price for one unit was around \u20ac20.<\/p>\n\n\n\n<figure class=\"wp-block-table is-style-stripes\"><table><thead><tr><th>Reference<\/th><th>Component type \/ Value<\/th><th>Quantity<\/th><th>Description<\/th><th>(approx.) Price in \u20ac<\/th><th>Check<\/th><\/tr><\/thead><tbody><tr><td><\/td><td>ISA 8-Bit Backplane<\/td><td>1<\/td><td>I ordered mine from JLCPCB<\/td><td>\u00a35.00<\/td><td><\/td><\/tr><tr><td>U1<\/td><td>74HCT74<\/td><td>1<\/td><td>Integrated Circuit (IC): DIP-14 Package<br>Mouser 595-SN74AHCT74N<\/td><td>0.60 EUR<\/td><td><\/td><\/tr><tr><td>U2<\/td><td>74HCT14<\/td><td>1<\/td><td>Integrated Circuit (IC): DIP-14 Package<br>Mouser 595-SN74AHCT14N<\/td><td>0.60 EUR<\/td><td><\/td><\/tr><tr><td>U3<\/td><td>LM7905C<\/td><td>1<\/td><td>Integrated Circuit (IC): -5V Voltage Regulator<br>Mouser 512-LM7905CT<\/td><td>0.50 EUR<\/td><td><\/td><\/tr><tr><td>U1, U2<\/td><td>DIP-14<\/td><td>2<\/td><td>IC Socket: 300 mil socket<br>Mouser 517-4814-3000-CP<\/td><td>0.40 EUR<\/td><td><\/td><\/tr><tr><td>D1<\/td><td>3 mm LED, blue<\/td><td>1<\/td><td>LED display<br>Mouser 696-SSL-LX3054USBD<\/td><td>0.30 EUR<\/td><td>x<\/td><\/tr><tr><td>D2<\/td><td>3 mm LED, two-colour red\/green<\/td><td>1<\/td><td>LED display<br>Mouser 696-SSL-LX3054IGW<\/td><td>0.40 EUR<\/td><td>x<\/td><\/tr><tr><td>D3, D4<\/td><td>1N4148<\/td><td>2<\/td><td>Diode<br>Mouser 512-1N4148<\/td><td>0.20 EUR<\/td><td>x<\/td><\/tr><tr><td>SW1<\/td><td>6 mm<\/td><td>1<\/td><td>Short-stroke push button: Short-stroke push button, straight<br>Mouser 653-B3F-1000<\/td><td>0.30 EUR<\/td><td><\/td><\/tr><tr><td>Page 1<\/td><td>ATX<\/td><td>1<\/td><td>Connector: 20-Pin power connector<br>Mouser 538-46015-2006<\/td><td>0.80 EUR<\/td><td><\/td><\/tr><tr><td>P2, P3<\/td><td>Pen holder<\/td><td>2<\/td><td>Connector: 4-pin, 2.54 mm pitch<br>Mouser 649-68002-104HLF<\/td><td>0.20 EUR<\/td><td><\/td><\/tr><tr><td>BUS1-BUS7<\/td><td>ISA slot<\/td><td>7<\/td><td>Connector: 62-pin card edge connector, 2.54 mm pitch<br>Mouser 571-6-5530843-5<\/td><td>3.80 euros<\/td><td><\/td><\/tr><tr><td>C1 \u2013 C19<\/td><td>10 \u00b5F<\/td><td>19<\/td><td>Capacitor: 16V, MLCC, 5 mm pitch<br>Mouser 810-FG28X5R1E106MR06<\/td><td>\u00a31.20<\/td><td><\/td><\/tr><tr><td>C20<\/td><td>1 \u00b5F<\/td><td>1<\/td><td>Capacitor: MLCC, 5 mm pitch<br>Mouser 810-FG28X5R1H105KRT0<\/td><td>0.20 EUR<\/td><td><\/td><\/tr><tr><td>C21, C22<\/td><td>0.1 \u00b5F<\/td><td>2<\/td><td>Capacitor: MLCC, 5 mm pitch<br>Mouser 594-K104K15X7RF53H5<\/td><td>0.20 EUR<\/td><td><\/td><\/tr><tr><td>R1, R2<\/td><td>10 kOhm, wired<\/td><td>2<\/td><td>Resistance<br>Mouser 291-10K-RC<\/td><td>0.30 EUR<\/td><td>x<\/td><\/tr><tr><td>R3<\/td><td>1 kOhm, wirewound<\/td><td>1<\/td><td>Resistance<br>Mouser 291-1K-RC<\/td><td>0.30 EUR<\/td><td>x<\/td><\/tr><tr><td>R4 \u2013 R7<\/td><td>470 Ohm, wirewound<\/td><td>4<\/td><td>Resistance<br>Mouser 291-470-RC<\/td><td>0.30 EUR<\/td><td>x<\/td><\/tr><tr><td>RR1 \u2013 RR5<\/td><td><\/td><td><\/td><td>Resistor network: do not populate<br>(Optional, should not be populated.)<\/td><td>0.00 EUR<\/td><td>\u2013<\/td><\/tr><\/tbody><tfoot><tr><td><\/td><td><\/td><td><\/td><td>Total material costs (guideline value)<\/td><td>17.00 EUR<\/td><td><\/td><\/tr><\/tfoot><\/table><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Aufbau\"><\/span>Structure<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Varianten\"><\/span>Variations<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>Recommended logic family <strong>CMOS 74HCT series<\/strong><\/p>\n\n\n\n<ul>\n<li>Possible alternatives: <strong>74AHCT<\/strong> or <strong>74ACT<\/strong><\/li>\n\n\n\n<li>TTL-ICs (74LS, 74ALS, 74F) work but consume more power.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>LEDs<\/strong><\/h3>\n\n\n\n<ul>\n<li><strong>Power LED (D1):<\/strong> Recommended 3mm blue LED; 5mm or other colours also work<\/li>\n\n\n\n<li><strong>Activity LED (D2):<\/strong> recommended 3 mm red\/green bi-colour LED with <strong>two connections<\/strong> (antiparallelly connected LED crystals)<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Capacitors<\/strong><\/h3>\n\n\n\n<ul>\n<li>Recommended: Ceramic multilayer capacitors with 5 mm pitch<\/li>\n\n\n\n<li>2.5 mm pitch or axial capacitors can be adapted by bending the leads<\/li>\n\n\n\n<li>Electrolytic or tantalum capacitors for C1\u2013C19 (10 \u00b5F) are possible \u2014 <strong>Observe polarity!<\/strong><\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Reihenfolge\"><\/span>Order<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>The instructions on Github were more detailed than I would have written them, so I've translated them, changed the order slightly, and reproduced them here. <a href=\"https:\/\/github.com\/skiselev\/isa8_backplane\/blob\/master\/Building_Instructions.md\">This way to the original<\/a>.<\/p>\n\n\n\n<ol>\n<li>Check circuit board for visible defects (scratches, short circuits)<\/li>\n\n\n\n<li>Clean PCB with alcohol<\/li>\n\n\n\n<li>Solder components from low to high<\/li>\n\n\n\n<li>Solder diodes D3 and D4 in place \u2014 <strong>Consider polarity<\/strong> (Black ring = marking)<\/li>\n\n\n\n<li>Solder resistors R1\u2013R7<\/li>\n\n\n\n<li>Voltage regulator U3 shape and solder in \u2014 hole for heatsink must align with PCB hole<\/li>\n\n\n\n<li>Solder capacitors C1\u2013C22 \u2014 <strong>Consider polarity<\/strong>, falls polarised<\/li>\n\n\n\n<li>Solder in DIP sockets U1 and U2 \u2014 <strong>Observe alignment<\/strong><\/li>\n\n\n\n<li>Solder LEDs D1 and D2 <strong>Note polarity at D1<\/strong><\/li>\n\n\n\n<li>Solder pin headers P2\u2013P3<\/li>\n\n\n\n<li>Solder switch SW1<\/li>\n\n\n\n<li>Solder ATX power connector P1<\/li>\n\n\n\n<li>Solder ISA card connectors BUS1\u2013BUS7<\/li>\n\n\n\n<li>Carefully check all solder joints; re-solder if necessary.<\/li>\n\n\n\n<li>Optional: Check for short circuits and supply voltages with a multimeter<\/li>\n\n\n\n<li>Clean the board thoroughly with alcohol, wipes, and a toothbrush<\/li>\n\n\n\n<li>Carefully insert ICs into the sockets \u2014 align pins on a hard, non-static surface if necessary<\/li>\n\n\n\n<li>Check the orientation of the ICs; ensure no pins are bent<\/li>\n\n\n\n<li>Re-inspect finished circuit board<\/li>\n\n\n\n<li>Install Micro-8088-Board and other ISA cards, connect power supply<\/li>\n\n\n\n<li>Turn on, test, install software \u2014 <strong>and have fun!<\/strong><\/li>\n<\/ol>\n\n\n\n<h1 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Inbetriebnahme\"><\/span>Commissioning<span class=\"ez-toc-section-end\"><\/span><\/h1>\n\n\n\n<p>You can supply power to the backplane, and you should do so before plugging in a card, but otherwise, it can't do much itself. It's more of a link.<\/p>\n\n\n\n<h1 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Sonstiges\"><\/span>Miscellaneous<span class=\"ez-toc-section-end\"><\/span><\/h1>\n\n\n\n<h2 class=\"wp-block-heading\">Data sheets<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">7474<\/h3>\n\n\n\n<p>Source: <a href=\"https:\/\/www.alldatasheet.com\/view.jsp?Searchword=7474\">https:\/\/www.alldatasheet.com\/view.jsp?Searchword=7474<\/a><\/p>\n\n\n\n<div data-wp-interactive=\"core\/file\" class=\"wp-block-file\"><object data-wp-bind--hidden=\"!state.hasPdfPreview\"  class=\"wp-block-file__embed\" data=\"https:\/\/www.fambach.net\/wp-content\/uploads\/SN5474.pdf\" type=\"application\/pdf\" style=\"width:100%;height:600px\" aria-label=\"Embed of SN5474.\"><\/object><a id=\"wp-block-file--media-1350163a-327d-40b8-bf60-c014dd88f2d4\" href=\"https:\/\/www.fambach.net\/wp-content\/uploads\/SN5474.pdf\">SN5474<\/a><a href=\"https:\/\/www.fambach.net\/wp-content\/uploads\/SN5474.pdf\" class=\"wp-block-file__button wp-element-button\" download aria-describedby=\"wp-block-file--media-1350163a-327d-40b8-bf60-c014dd88f2d4\">Download<\/a><\/div>\n\n\n\n<h3 class=\"wp-block-heading\">7414<\/h3>\n\n\n\n<p>Source: <a href=\"https:\/\/www.alldatasheet.com\/datasheet-pdf\/pdf\/27375\/TI\/7414.html\">https:\/\/www.alldatasheet.com\/datasheet-pdf\/pdf\/27375\/TI\/7414.html<\/a><\/p>\n\n\n\n<div data-wp-interactive=\"core\/file\" class=\"wp-block-file\"><object data-wp-bind--hidden=\"!state.hasPdfPreview\"  class=\"wp-block-file__embed\" data=\"https:\/\/www.fambach.net\/wp-content\/uploads\/SN5414.pdf\" type=\"application\/pdf\" style=\"width:100%;height:600px\" aria-label=\"Embed of SN5414.\"><\/object><a id=\"wp-block-file--media-0a401b91-7663-4412-b679-70b1fa7a1230\" href=\"https:\/\/www.fambach.net\/wp-content\/uploads\/SN5414.pdf\">SN5414<\/a><a href=\"https:\/\/www.fambach.net\/wp-content\/uploads\/SN5414.pdf\" class=\"wp-block-file__button wp-element-button\" download aria-describedby=\"wp-block-file--media-0a401b91-7663-4412-b679-70b1fa7a1230\">Download<\/a><\/div>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Generelle_Tips\"><\/span>General Tips<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Lotstellen\"><\/span>Soldering points<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>Check the solder joints on the ICs again carefully, preferably with a microscope or magnifying glass, for short circuits and contact. Measure with a multimeter or continuity tester.<\/p>\n\n\n\n<p>For small solder joints on through-hole components, use flux if possible; it makes life easier and increases the quality of the connection.<\/p>\n\n\n\n<h1 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Probleme\"><\/span>Problems<span class=\"ez-toc-section-end\"><\/span><\/h1>\n\n\n\n<p><\/p>\n\n\n\n<h1 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Fazit\"><\/span>Conclusion<span class=\"ez-toc-section-end\"><\/span><\/h1>\n\n\n\n<figure class=\"wp-block-table is-style-stripes\"><table><thead><tr><th>Description<\/th><th>Worth<\/th><\/tr><\/thead><tbody><tr><td>Successful<\/td><td>Yes<\/td><\/tr><tr><td>Price per piece<\/td><td>~20\u20ac<\/td><\/tr><tr><td>Soldering time<\/td><td>1 hour<\/td><\/tr><tr><td>Function<\/td><td>Gut<\/td><\/tr><tr><td>Is it worth it<\/td><td>Yes, a nice addition to the set<\/td><\/tr><tr><td>Restrictions<\/td><td>8-bit, no additional functionality<\/td><\/tr><\/tbody><\/table><figcaption class=\"wp-element-caption\">Conclusion to the project<\/figcaption><\/figure>\n\n\n\n<h1 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Verwandte_Beitrage\"><\/span>Related Posts<span class=\"ez-toc-section-end\"><\/span><\/h1>\n\n\n<ul class=\"display-posts-listing\">\n<li class=\"listing-item\"><a class=\"title\" href=\"https:\/\/www.fambach.net\/en\/retro_pojekt-isa-8bit-backplane\/\">Retro Project - ISA 8-Bit Backplane<\/a><\/li>\n<li class=\"listing-item\"><a class=\"title\" href=\"https:\/\/www.fambach.net\/en\/retro_pojekt-voltage-blaster\/\">Retro Project \u2013 Voltage Blaster<\/a><\/li>\n<li class=\"listing-item\"><a class=\"title\" href=\"https:\/\/www.fambach.net\/en\/retro_pojekt-8bit-isa-ethernet-card-isa8_eth\/\">Retro Project \u2013 8-Bit ISA Ethernet Card (isa8_eth)<\/a><\/li>\n<li class=\"listing-item\"><a class=\"title\" href=\"https:\/\/www.fambach.net\/en\/retro-projekt-fdc-usb-floppy-controller\/\">Retro Project \u2013 FDC USB Floppy Disk Controller<\/a><\/li>\n<li class=\"listing-item\"><a class=\"title\" href=\"https:\/\/www.fambach.net\/en\/retro_pojekt-retro-projekt-floppy-disk-controller-isa-fdc\/\">Retro Project \u2013 Floppy Disk Controller (isa-fdc)<\/a><\/li>\n<li class=\"listing-item\"><a class=\"title\" href=\"https:\/\/www.fambach.net\/en\/retro_pojekt-template-6\/\">Retro Project \u2013 ROMOS<\/a><\/li>\n<li class=\"listing-item\"><a class=\"title\" href=\"https:\/\/www.fambach.net\/en\/retro_pojekt-usb-auf-rs232-mouse-adapter\/\">Retro Project \u2013 USB to RS232 Mouse Adapter<\/a><\/li>\n<li class=\"listing-item\"><a class=\"title\" href=\"https:\/\/www.fambach.net\/en\/retro_pojekt-retro-projekt-monotech-isa-doublerom\/\">Retro Project \u2013 Monotech ISA Double ROM<\/a><\/li>\n<li class=\"listing-item\"><a class=\"title\" href=\"https:\/\/www.fambach.net\/en\/retro_pojekt-template-4\/\">Retro Project - Greaseweazle 4.1<\/a><\/li>\n<li class=\"listing-item\"><a class=\"title\" href=\"https:\/\/www.fambach.net\/en\/retro_pojekt-template-3\/\">Retro Project \u2013 ATX Form Card<\/a><\/li>\n<\/ul>\n\n\n\n<h1 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Quellen\"><\/span>Sources<span class=\"ez-toc-section-end\"><\/span><\/h1>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Zum_Projekt\"><\/span>To the project<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p><a href=\"https:\/\/github.com\/skiselev\/isa8_backplane\">GitHub Link<\/a><\/p>\n\n\n\n<p><a href=\"https:\/\/github.com\/skiselev\/micro_8088\/blob\/master\/README.md#bill-of-materials---version-11\">Parts list<\/a><\/p>\n\n\n\n<p><a href=\"https:\/\/github.com\/skiselev\/micro_8088\/tree\/master\/gerber\">Gerber files<\/a><\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Retro_Seiten\"><\/span>Retro pages<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p><a href=\"https:\/\/archive.org\">https:\/\/archive.org<\/a> \u2013 Old software, magazines, manuals, and much more.<\/p>\n\n\n\n<p><a href=\"https:\/\/theretroweb.com\">https:\/\/theretroweb.com<\/a> \u2013 PC Hardware Directory.<\/p>\n\n\n\n<p><a href=\"https:\/\/www.winhistory.de\/index.php\">https:\/\/www.winhistory.de\/index.php<\/a> \u2013 DOS, Windows Version Descriptions.<\/p>\n\n\n\n<p>Win 3.1x Tools and Tricks<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Retro_Foren\"><\/span>Retro Forensics<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p><a href=\"https:\/\/forum.classic-computing.de\/forum\">https:\/\/forum.classic-computing.de\/forum<\/a> \u2013 German\/English forum with many retro computer enthusiasts.<\/p>\n\n\n\n<p><a href=\"https:\/\/www.vogons.org\">https:\/\/www.vogons.org<\/a> \u2013 I have found many tips on hardware here, they also have a driver directory.<\/p>\n\n\n\n<p><a href=\"https:\/\/www.dosforum.de\">https:\/\/www.dosforum.de<\/a> \u2013 Forum with strict rules and very helpful regarding DOS, Windows questions are not welcome.<\/p>\n\n\n\n<p><a href=\"https:\/\/dosreloaded.de\">https:\/\/dosreloaded.de<\/a> \u2013 DOS, hardware repairs, BIOS files and more.<\/p>\n\n\n\n<p><a href=\"https:\/\/www.winhistory-forum.net\">https:\/\/www.winhistory-forum.net<\/a> DOS and Windows history.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Retro_Shops\"><\/span>Retro Shops<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p><a href=\"https:\/\/ram-co-shop.de\">https:\/\/ram-co-shop.de<\/a> - PC parts, including newer ones, have ordered a lot from there and it's always worked.<\/p>\n\n\n\n<p><a href=\"http:\/\/www.amoretro.de\/\">http:\/\/www.amoretro.de<\/a> \u2013 Sold on eBay and has a nice directory of old hardware<\/p>\n\n\n\n<p><a href=\"https:\/\/retroreiz.de\">https:\/\/retroreiz.de<\/a> \u2013 Atari, Nintendo, Sega and others.<\/p>\n\n\n\n<p><a href=\"https:\/\/www.retroworld.info\/de\">https:\/\/www.retroworld.info\/de<\/a> \u2013 Stickers, signs and more.<\/p>\n\n\n\n<p><a href=\"https:\/\/retesa-nb.de\">https:\/\/retesa-nb.de<\/a> \u2013 Older PC hardware<\/p>\n\n\n\n<p><a href=\"https:\/\/www.retro8bitshop.com\">https:\/\/www.retro8bitshop.com<\/a> \u2013 C64 tricky<\/p>\n\n\n\n<h1 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Logbuch\"><\/span>Logbook<span class=\"ez-toc-section-end\"><\/span><\/h1>\n\n\n\n<figure class=\"wp-block-table is-style-stripes\"><table><thead><tr><th>Date<\/th><th>Description<\/th><\/tr><\/thead><tbody><tr><td>30.08.2025<\/td><td>Post created and PCB ordered.<\/td><\/tr><tr><td>09.09.2025<\/td><td>Boards arrived<\/td><\/tr><tr><td>20.06.2025<\/td><td>Gathered stuff<\/td><\/tr><tr><td>21.06.2025<\/td><td>Soldered the board, unfortunately I'm missing the 20-pin ATX connector. I only have a 24-pin one that I could shorten, but I'd rather wait until the ordered one arrives.<\/td><\/tr><tr><td><\/td><td><\/td><\/tr><tr><td><\/td><td><\/td><\/tr><tr><td><\/td><td><\/td><\/tr><tr><td><\/td><td><\/td><\/tr><tr><td><\/td><td><\/td><\/tr><tr><td><\/td><td><\/td><\/tr><tr><td><\/td><td><\/td><\/tr><tr><td><\/td><td><\/td><\/tr><tr><td><\/td><td><\/td><\/tr><tr><td><\/td><td><\/td><\/tr><tr><td><\/td><td><\/td><\/tr><tr><td><\/td><td><\/td><\/tr><tr><td><\/td><td><\/td><\/tr><tr><td><\/td><td><\/td><\/tr><tr><td><\/td><td><\/td><\/tr><tr><td><\/td><td><\/td><\/tr><\/tbody><\/table><figcaption class=\"wp-element-caption\">Revision history<\/figcaption><\/figure>\n\n\n\n<p><\/p>\n\n\n\n<p><\/p>\n\n\n\n<p><\/p>\n\n\n\n<p><\/p>","protected":false},"excerpt":{"rendered":"<p>This is the motherboard that connects all of Sergey Kiselev's projects. The backplane consists of 7x 8-bit ISA slots, an ATX connector, two LEDs and a power button. Other than that, it doesn't offer much else apart from forming a genuine 8088 PC from all the 8-bit ISA cards. Link to the project Link to the project\u2026<\/p>\n<a href=\"https:\/\/www.fambach.net\/en\/retro_pojekt-template-3\/\" class=\"read-more-link\">Carry on reading <span class=\"screen-reader-text\">\"Retro Projekt &#8211; ATX Form Card\"<\/span> <span class=\"meta-nav\">\u2192<\/span><\/a>","protected":false},"author":1,"featured_media":15837,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_lmt_disableupdate":"","_lmt_disable":"","footnotes":""},"categories":[821,885],"tags":[981,983,812,884,811,982],"modified_by":"sfambach","_links":{"self":[{"href":"https:\/\/www.fambach.net\/en\/wp-json\/wp\/v2\/posts\/14256"}],"collection":[{"href":"https:\/\/www.fambach.net\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.fambach.net\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.fambach.net\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.fambach.net\/en\/wp-json\/wp\/v2\/comments?post=14256"}],"version-history":[{"count":11,"href":"https:\/\/www.fambach.net\/en\/wp-json\/wp\/v2\/posts\/14256\/revisions"}],"predecessor-version":[{"id":15845,"href":"https:\/\/www.fambach.net\/en\/wp-json\/wp\/v2\/posts\/14256\/revisions\/15845"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.fambach.net\/en\/wp-json\/wp\/v2\/media\/15837"}],"wp:attachment":[{"href":"https:\/\/www.fambach.net\/en\/wp-json\/wp\/v2\/media?parent=14256"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.fambach.net\/en\/wp-json\/wp\/v2\/categories?post=14256"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.fambach.net\/en\/wp-json\/wp\/v2\/tags?post=14256"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}