{"id":39456,"date":"2026-02-13T20:00:00","date_gmt":"2026-02-13T19:00:00","guid":{"rendered":"https:\/\/www.jungsi.de\/?p=39456"},"modified":"2026-06-03T10:12:11","modified_gmt":"2026-06-03T08:12:11","slug":"kempston-joystick-interface-sinclair-zx-spectrum","status":"publish","type":"post","link":"https:\/\/www.jungsi.de\/en\/kempston-joystick-interface-sinclair-zx-spectrum\/","title":{"rendered":"Kempston Joystick Interface [Sinclair ZX Spectrum]"},"content":{"rendered":"<p class=\"wp-block-paragraph\"><strong>Kempston Joystick Interface (1983) \u2013 the standard that gave the Spectrum that \u2018arcade feel\u2019<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">When I think back to my Spectrum days, one thing stands out above all else: the keyboard. I played an astonishing amount back then without ever using a joystick \u2013 simply because I didn\u2019t have the right interface. It was only later that I realised just how much a small accessory can change the gaming experience. And that\u2019s exactly what the Kempston Joystick Interface is: unassuming, robust \u2013 and, for many games, still the most obvious joystick option today.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Key facts<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Year of publication: 1983<\/li>\n\n\n\n<li>Manufacturer: Kempston Micro Electronics Ltd.<\/li>\n\n\n\n<li>System: Sinclair ZX Spectrum (\u00fcber den Expansionsport \/ Edge-Connector)<\/li>\n\n\n\n<li>Connection: 9-pin D-Sub (Atari standard) for joysticks<\/li>\n\n\n\n<li>Special feature: Communication via a dedicated I\/O port (Kempston standard); not a pure keyboard emulation<\/li>\n<\/ul>\n\n\n\n<!--more-->\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Two versions in my collection: \u2018standing\u2019 and \u2018lying down\u2019<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">I have two Kempston interfaces in my collection \u2013 and they differ in one respect that you notice straight away in everyday use:<\/p>\n\n\n\n<p class=\"wp-block-paragraph translation-block\"><em>Option 1: The \u2018upright\u2019 design<\/em><br>In this design, the interface is positioned quite high at the back of the Spectrum. This looks striking and sometimes requires less depth at the rear, but \u2013 depending on the joystick cable \u2013 can exert greater leverage on the connector.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"768\" src=\"https:\/\/www.jungsi.de\/blog\/wp-content\/uploads\/Kempston-Joystick-Interface-2-oben-1024x768.jpg\" alt=\"\" class=\"wp-image-39593\" srcset=\"https:\/\/www.jungsi.de\/blog\/wp-content\/uploads\/Kempston-Joystick-Interface-2-oben-1024x768.jpg 1024w, https:\/\/www.jungsi.de\/blog\/wp-content\/uploads\/Kempston-Joystick-Interface-2-oben-300x225.jpg 300w, https:\/\/www.jungsi.de\/blog\/wp-content\/uploads\/Kempston-Joystick-Interface-2-oben.jpg 1400w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">Kempston Joystick Interface \u2013 Version 1 (top view); when connected to the Spectrum, the design appears rather \u2018upright\u2019.<\/figcaption><\/figure>\n<\/div>\n\n\n<p class=\"wp-block-paragraph translation-block\"><em>Option 2: The \u2018horizontal\u2019 design<\/em><br>This version sits flatter and often looks \u2018neater\u2019 on the computer because it rests on top of it. However, you may need a little more space behind the Spectrum, depending on how the computer is positioned.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"410\" height=\"308\" src=\"https:\/\/www.jungsi.de\/blog\/wp-content\/uploads\/2012\/07\/Kempston-Interface.jpg\" alt=\"Kempston Interface\" class=\"wp-image-1221\" srcset=\"https:\/\/www.jungsi.de\/blog\/wp-content\/uploads\/2012\/07\/Kempston-Interface.jpg 410w, https:\/\/www.jungsi.de\/blog\/wp-content\/uploads\/2012\/07\/Kempston-Interface-300x225.jpg 300w\" sizes=\"auto, (max-width: 410px) 100vw, 410px\" \/><figcaption class=\"wp-element-caption\">Kempston Joystick Interface \u2013 Version 2 (top view); this model sits more \u2018flat\u2019 on the Spectrum.<\/figcaption><\/figure>\n<\/div>\n\n\n<p class=\"wp-block-paragraph translation-block\"><strong>What both models have in common: no through-wired expansion port<\/strong><br>Interesting (and important in practice): on both of my interfaces, the expansion port is not routed out as an additional socket. This means that, with these variants, the Kempston interface is usually the last device on the expansion port. Anyone wishing to operate several expansions simultaneously (e.g. printer interface, memory or disk expansion) will then need either a different solution or a separate expansion hub.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>What makes the Kempston so special<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">There was never a single standard joystick for the Spectrum. Many joystick solutions work via keyboard mapping: the joystick internally \u2018presses\u2019 specific keys (cursor, number pad, etc.). The Kempston interface is different: it transmits the joystick status via its own hardware port. This makes the input for games and programmes very direct \u2013 and that is precisely why \u2018Kempston\u2019 became a standard over time.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In short: if a game offers \u2018Kempston\u2019 in the menu, there\u2019s a very good chance it will be responsive and enjoyable to play.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>How the query works (explained simply)<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The joystick state is returned as a number. Neutral is 0. Each direction has a fixed value, and firing adds another value to this. Diagonal movements are created by adding the values together.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><em>Typical values (Kempston standard)<\/em><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Right: 1<\/li>\n\n\n\n<li>Links: 2<\/li>\n\n\n\n<li>Down: 4<\/li>\n\n\n\n<li>Up: 8<\/li>\n\n\n\n<li>Fire: +16<\/li>\n\n\n\n<li>Centre: 0<\/li>\n\n\n\n<li>Diagonal: Sum of the directions (e.g. up + right = 8 + 1 = 9)<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><em>Mini test in BASIC<\/em><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">If you want to check the interface quickly, you can do so without even needing a special programme:<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>10 PRINT IN 31\n20 GO TO 10\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">In neutral mode, the display should always show 0. If you press a directional button or the fire button, the values will change accordingly.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><em>Practical tip: mechanical stress and correct attachment<\/em><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The Spectrum\u2019s expansion port is handy, but it\u2019s not indestructible \u2013 especially after decades of use. That\u2019s why there are a few things I bear in mind whenever I\u2019m adding extensions to the Spectrum:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Always apply it straight across; don\u2019t let it tilt<\/li>\n\n\n\n<li>Do not press with force<\/li>\n\n\n\n<li>When peeling, make sure to keep the blade straight (do not tear sideways)<\/li>\n\n\n\n<li>Route the joystick cable so that it does not constantly pull on the interface<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">It is the design itself (\u2018upright\u2019 vs. \u2018horizontal\u2019) that makes all the difference here: the flatter version often looks more relaxed on a shelf or on a table, whilst the taller version is sometimes more space-saving.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"600\" height=\"450\" src=\"https:\/\/www.jungsi.de\/blog\/wp-content\/uploads\/2012\/12\/Kempston-Joystick-Interface-und-Quickshot-Joystick.jpg\" alt=\"\" class=\"wp-image-2476\" srcset=\"https:\/\/www.jungsi.de\/blog\/wp-content\/uploads\/2012\/12\/Kempston-Joystick-Interface-und-Quickshot-Joystick.jpg 600w, https:\/\/www.jungsi.de\/blog\/wp-content\/uploads\/2012\/12\/Kempston-Joystick-Interface-und-Quickshot-Joystick-300x225.jpg 300w\" sizes=\"auto, (max-width: 600px) 100vw, 600px\" \/><\/figure>\n<\/div>\n\n\n<p class=\"wp-block-paragraph\"><strong>Why the Kempston is an essential accessory for me these days<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">I find it almost ironic: I used to play without a joystick at all. These days, for me, a Kempston interface is one of those accessories that instantly makes the Spectrum feel \u2018complete\u2019 \u2013 not because it\u2019s technically spectacular, but because it changes the feel of the game so dramatically.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">And with two different designs in the collection, it\u2019s even better: it really brings home the point that there wasn\u2019t just \u2018the\u2019 Kempston interface, but also variants that feel quite different in everyday use \u2013 even if, ultimately, they both deliver the same standard.<\/p>","protected":false},"excerpt":{"rendered":"<p>Kempston Joystick Interface (1983) \u2013 der Standard, der dem Spectrum das \u201eArcade-Gef\u00fchl\u201c gab Wenn ich an meine Spectrum-Zeit zur\u00fcckdenke, dann war das vor allem: Tastatur. \u2026<\/p>","protected":false},"author":2,"featured_media":39593,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"ngg_post_thumbnail":0,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":true,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_feature_clip_id":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_post_was_ever_published":false,"_links_to":"","_links_to_target":""},"categories":[102],"tags":[4843,4737,666],"class_list":["post-39456","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-zx-spectrum","tag-englisch-verfuegbar","tag-hardware","tag-sinclair"],"wp-worthy-pixel":{"ignored":false,"public":"b4f0f151ec9749d98f24cd3d6c494d81","server":"","url":"https:\/\/vg02.met.vgwort.de\/na\/b4f0f151ec9749d98f24cd3d6c494d81"},"wp-worthy-type":"normal","jetpack_sharing_enabled":true,"jetpack_featured_media_url":"https:\/\/www.jungsi.de\/blog\/wp-content\/uploads\/Kempston-Joystick-Interface-2-oben.jpg","_links":{"self":[{"href":"https:\/\/www.jungsi.de\/en\/wp-json\/wp\/v2\/posts\/39456","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.jungsi.de\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.jungsi.de\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.jungsi.de\/en\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.jungsi.de\/en\/wp-json\/wp\/v2\/comments?post=39456"}],"version-history":[{"count":1,"href":"https:\/\/www.jungsi.de\/en\/wp-json\/wp\/v2\/posts\/39456\/revisions"}],"predecessor-version":[{"id":42435,"href":"https:\/\/www.jungsi.de\/en\/wp-json\/wp\/v2\/posts\/39456\/revisions\/42435"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.jungsi.de\/en\/wp-json\/wp\/v2\/media\/39593"}],"wp:attachment":[{"href":"https:\/\/www.jungsi.de\/en\/wp-json\/wp\/v2\/media?parent=39456"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.jungsi.de\/en\/wp-json\/wp\/v2\/categories?post=39456"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.jungsi.de\/en\/wp-json\/wp\/v2\/tags?post=39456"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}