{"id":13548,"date":"2017-09-24T11:30:59","date_gmt":"2017-09-24T10:30:59","guid":{"rendered":"http:\/\/www.jungsi.de\/?p=13548"},"modified":"2026-08-24T15:24:25","modified_gmt":"2026-08-24T13:24:25","slug":"gammadisk-sinclair-zx-spectrum","status":"publish","type":"post","link":"https:\/\/www.jungsi.de\/en\/gammadisk-sinclair-zx-spectrum\/","title":{"rendered":"Gammadisk [Sinclair ZX Spectrum]"},"content":{"rendered":"<p class=\"wp-block-paragraph translation-block\">The <em>Gammadisk interface<\/em> is a special floppy disk interface for the <em>Sinclair ZX Spectrum<\/em>. The original is extremely hard to find, and reproductions are no longer available either. I am therefore especially pleased that <em>Claus-Peter Casper<\/em> assembled a complete unit for me. Many thanks again!<\/p>\n\n\n\n<p class=\"wp-block-paragraph translation-block\">This interface was manufactured in limited quantities in 1986 by the German company *MIDAS*. It is software-compatible with the Betadisk interface from *Technology Research* (UK). However, the Gammadisk featured improvements over the original\u2014specifically, the addition of an 8255 3-port PIO, which enabled the inclusion of ports for a Kempston joystick and a printer.<br>The floppy disks (720k DD) are compatible with the Betadisk 48 (successfully tested). *Claus-Peter Casper* took the trouble to create a new PCB layout (as original schematics were unavailable) and produce replicas of the interface housed in an excellent case.<\/p>\n\n\n\n<!--more-->\n\n\n\n<p class=\"wp-block-paragraph\">The housing contains two circuit boards: one holds the control circuitry for the joystick and printer ports as well as the power supply for a floppy disk drive, while the second board houses the controller and connector for the disk drive itself. The two boards are linked via an adapter; additionally, the interface port is routed externally to allow for the connection of further interfaces. The NMI button (known as the \"Magic Button\" on the original unit) is located on the left side. Unlike the Beta Disk interface\u2014where the Spectrum is powered through the interface itself\u2014the Gamma interface allows the Spectrum to be powered directly, as usual.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Technical data:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Floppy controller SAB-1793 (no other!)<\/li>\n\n\n\n<li>3-Port-PIO 8255<\/li>\n\n\n\n<li>NMI push-button<\/li>\n\n\n\n<li>34-pol. Shugart-Bus<\/li>\n\n\n\n<li>Joystick port<\/li>\n\n\n\n<li>Printer connection<\/li>\n\n\n\n<li>I\/O bank switching<\/li>\n\n\n\n<li>fed-through system bus<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Up to four drives can be connected to the interface. The drives must be configured accordingly (DS0, DS1, etc.). Ideally, DD drives that can be configured via jumpers should be used.<\/p>\n\n\n<div class=\"wp-block-image wp-image-14075\">\n<figure class=\"aligncenter\"><img loading=\"lazy\" decoding=\"async\" width=\"800\" height=\"600\" src=\"https:\/\/www.jungsi.de\/blog\/wp-content\/uploads\/gamma-disk-interface-rueckseite-1.jpg\" alt=\"R\u00fcckseite\" class=\"wp-image-14075\" srcset=\"https:\/\/www.jungsi.de\/blog\/wp-content\/uploads\/gamma-disk-interface-rueckseite-1.jpg 800w, https:\/\/www.jungsi.de\/blog\/wp-content\/uploads\/gamma-disk-interface-rueckseite-1-300x225.jpg 300w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><figcaption class=\"wp-element-caption\">back<\/figcaption><\/figure>\n<\/div>\n\n\n<p class=\"wp-block-paragraph translation-block\">After switching on the Spectrum with the interface connected, BASIC starts up if no autoboot disk is inserted. TR-DOS is activated using<br><em>RANDOMIZE USR 15360<\/em> (+ Enter)<br>or<br><em>RANDOMIZE USR 99<\/em> (+ Enter)<br>Return to BASIC using<br><em>RETURN<\/em> (+ Enter)<\/p>\n\n\n\n<p class=\"wp-block-paragraph translation-block\">The printer interface is initialized using<br><em>RANDOMIZE USR 44<\/em><br>Afterward, <em>LLIST<\/em> and <em>LPRINT<\/em> can be used, and a COPY routine allows the screen to be printed out at a scaled size. The Gammadisk interface contains a 27C256 EPROM with two 16K memory banks. The first 16K section holds the ZX ROM with the adapted printing routines, while the second 16K section contains TR-DOS 4.12.<br>Commands are issued from BASIC just as with the Betadisk\u2014for example: <em>RANDOMIZE USR 15363 : REM: CAT<\/em><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Kopieren<\/strong><br>Mit nur einem Laufwerk wird zum Kopieren ganzer Disketten das Dienstprogramm &#8222;copydisk&#8220; benutzt.<br>Mit zwei Laufwerken steht der Befehl &#8222;<em>COPY<\/em>&#8220; zur Verf\u00fcgung \u2013 z.&nbsp;B.: <em>COPY &#8222;B:*&#8220;,&#8220;A:*&#8220;<\/em> (kopiert alle Dateien von Laufwerk B nach Laufwerk A)<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Der an der linken Seite angebrachte NMI-Knopf unterscheidet sich etwas in seiner Funktionsweise vom Betadisk-Interface. Beim Original wurde beim Dr\u00fccken des Magic-Buttons einfach eine einzelne Datei auf die Diskette mit dem Namen &#8222;@&#8220; geschrieben. Das n\u00e4chste Bet\u00e4tigen des Knopfs \u00fcberschreibt diese Daten,&nbsp;wenn sie vorher nicht umbenannt wurden. Das Gammadisk l\u00f6st das eleganter: wird der NMI gedr\u00fcckt, gibt es mehr M\u00f6glichkeiten:<br>B \u2013 Break: das laufende Programm wird unterbrochen und man kehrt in den BASIC-Editor zur\u00fcck<br>D \u2013 DOS: das System wird komplett zur\u00fcckgesetzt und befindet sich im gleichen Zustand wie nach dem Einschalten<br>R \u2013 Reset: bewirkt dasselbe wie ein <em>RANDOMIZE USR 0.<\/em>&nbsp;Programme und Daten gehen verloren, DOS wird jedoch nicht aufgerufen.<br>S \u2013 SAVE: ruft eine Eingabezeile auf, in der man einen Namen vergeben kann \u2013 danach wird das Programm in drei Teilen gespeichert:<br>&nbsp; &nbsp; 1) BASIC-Lader<br>&nbsp; &nbsp; 2) Bildschirminhalt<br>&nbsp; &nbsp; 3) Maschinencode<br>Nach dem Speichern wird das Programm fortgesetzt. Die gespeicherten Programme k\u00f6nnen dann wie gewohnt umbenannt, kopiert, gel\u00f6scht und geladen werden.<br><br><strong>Gammadisk mit Vision<\/strong><br>Durch eine Initiative des ZX-Teams (auch in Zusammenarbeit mit Claus-Peter Casper) ist es seit 2021 m\u00f6glich, ein anderes ROM f\u00fcr das Gammadisk zu verwenden.<br>Zum Einsatz kommt das Beta-Disk-ROM in der Version 4.83 zusammen mit der grafischen Oberfl\u00e4che &#8222;Vision&#8220; von Individual Software in der Version 1.7.<br>Als Steuerung kommt neben der Tastatur der Kempston-Joystick-Anschluss des Gammadisk zum Einsatz.<br>Dies alles wird durch den Austausch des EPROMs 27C256 mit einer gepatchten Version des ZX-Teams m\u00f6glich.<\/p>\n\n\n    <a href=\"https:\/\/www.jungsi.de\/en\/?dl=gammadisk-sinclair-zx-spectrum\/\" class=\"dl-box\">\n        <span class=\"dl-box__icon\" aria-hidden=\"true\">\u2b07<\/span>\n        <span class=\"dl-box__info\">\n            <span class=\"dl-box__label\">Gammadisk Vision17c-v483-KEMPSTON-PATCHED.ROM<\/span>\n                            <span class=\"dl-box__meta\">25,5 KB<\/span>\n                    <\/span>\n        <span class=\"dl-box__count\">18\u00d7<\/span>\n    <\/a>\n    \n\n\n\n<p class=\"wp-block-paragraph\"><strong>Links<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph translation-block\"><a href=\"http:\/\/www.casperonline.de\/zx\/index.html\" target=\"_blank\" rel=\"noopener noreferrer\">Gammadisk page by Claus-Peter Casper<\/a><br><a href=\"https:\/\/www.8bit-wiki.de\/Sinclair\/ZX_Spectrum\/interfaces\/Gamma-Disk\/\" target=\"_blank\" rel=\"noreferrer noopener\">Gammadisk documents in the 8-bit wiki<\/a><\/p>\n\n\n\n<p class=\"has-text-align-center wp-block-paragraph\"><iframe loading=\"lazy\" src=\"https:\/\/www.youtube.com\/embed\/ftEWeFT5G1k\" width=\"560\" height=\"315\" frameborder=\"0\" allowfullscreen=\"allowfullscreen\"><\/iframe><\/p>\n\n\n\n<figure class=\"wp-block-gallery has-nested-images columns-3 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=\"600\" height=\"800\" data-id=\"14078\" src=\"https:\/\/www.jungsi.de\/blog\/wp-content\/uploads\/gamma-disk-interface-1.jpg\" alt=\"Gamma Disk Interface\" class=\"wp-image-14078\" srcset=\"https:\/\/www.jungsi.de\/blog\/wp-content\/uploads\/gamma-disk-interface-1.jpg 600w, https:\/\/www.jungsi.de\/blog\/wp-content\/uploads\/gamma-disk-interface-1-225x300.jpg 225w\" sizes=\"auto, (max-width: 600px) 100vw, 600px\" \/><figcaption class=\"wp-element-caption\">Gamma Disk Interface<\/figcaption><\/figure>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"800\" height=\"600\" data-id=\"14075\" src=\"https:\/\/www.jungsi.de\/blog\/wp-content\/uploads\/gamma-disk-interface-rueckseite-1.jpg\" alt=\"R\u00fcckseite\" class=\"wp-image-14075\" srcset=\"https:\/\/www.jungsi.de\/blog\/wp-content\/uploads\/gamma-disk-interface-rueckseite-1.jpg 800w, https:\/\/www.jungsi.de\/blog\/wp-content\/uploads\/gamma-disk-interface-rueckseite-1-300x225.jpg 300w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><figcaption class=\"wp-element-caption\">back<\/figcaption><\/figure>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"800\" height=\"600\" data-id=\"14074\" src=\"https:\/\/www.jungsi.de\/blog\/wp-content\/uploads\/gamma-disk-interface-rueckseite-2-1.jpg\" alt=\"R\u00fcckseite\" class=\"wp-image-14074\" srcset=\"https:\/\/www.jungsi.de\/blog\/wp-content\/uploads\/gamma-disk-interface-rueckseite-2-1.jpg 800w, https:\/\/www.jungsi.de\/blog\/wp-content\/uploads\/gamma-disk-interface-rueckseite-2-1-300x225.jpg 300w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><figcaption class=\"wp-element-caption\"> back<\/figcaption><\/figure>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"800\" height=\"600\" data-id=\"14070\" src=\"https:\/\/www.jungsi.de\/blog\/wp-content\/uploads\/gamma-disk-interface-anschluesse-1.jpg\" alt=\"Anschl\u00fcsse\" class=\"wp-image-14070\" srcset=\"https:\/\/www.jungsi.de\/blog\/wp-content\/uploads\/gamma-disk-interface-anschluesse-1.jpg 800w, https:\/\/www.jungsi.de\/blog\/wp-content\/uploads\/gamma-disk-interface-anschluesse-1-300x225.jpg 300w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><figcaption class=\"wp-element-caption\">Connections<\/figcaption><\/figure>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"800\" height=\"600\" data-id=\"14073\" src=\"https:\/\/www.jungsi.de\/blog\/wp-content\/uploads\/gamma-disk-interface-nmi-taster-1.jpg\" alt=\"NMI Taster\" class=\"wp-image-14073\" srcset=\"https:\/\/www.jungsi.de\/blog\/wp-content\/uploads\/gamma-disk-interface-nmi-taster-1.jpg 800w, https:\/\/www.jungsi.de\/blog\/wp-content\/uploads\/gamma-disk-interface-nmi-taster-1-300x225.jpg 300w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><figcaption class=\"wp-element-caption\">NMI push-button<\/figcaption><\/figure>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"800\" height=\"600\" data-id=\"14072\" src=\"https:\/\/www.jungsi.de\/blog\/wp-content\/uploads\/gamma-disk-interface-interfaceanschluss-1.jpg\" alt=\"Interfaceanschluss\" class=\"wp-image-14072\" srcset=\"https:\/\/www.jungsi.de\/blog\/wp-content\/uploads\/gamma-disk-interface-interfaceanschluss-1.jpg 800w, https:\/\/www.jungsi.de\/blog\/wp-content\/uploads\/gamma-disk-interface-interfaceanschluss-1-300x225.jpg 300w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><figcaption class=\"wp-element-caption\">Interface connection<\/figcaption><\/figure>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"800\" height=\"600\" data-id=\"14076\" src=\"https:\/\/www.jungsi.de\/blog\/wp-content\/uploads\/gamma-disk-interface-sinclair-spectrum-48-und-diskettenlaufwerk-1.jpg\" alt=\"\" class=\"wp-image-14076\" srcset=\"https:\/\/www.jungsi.de\/blog\/wp-content\/uploads\/gamma-disk-interface-sinclair-spectrum-48-und-diskettenlaufwerk-1.jpg 800w, https:\/\/www.jungsi.de\/blog\/wp-content\/uploads\/gamma-disk-interface-sinclair-spectrum-48-und-diskettenlaufwerk-1-300x225.jpg 300w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><figcaption class=\"wp-element-caption\">Gamma Disk \u2013 Sinclair ZX Spectrum +48 and disk drive<\/figcaption><\/figure>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"800\" height=\"600\" data-id=\"14077\" src=\"https:\/\/www.jungsi.de\/blog\/wp-content\/uploads\/gamma-disk-interface-startdisk-1.jpg\" alt=\"Disk-Manager\" class=\"wp-image-14077\" srcset=\"https:\/\/www.jungsi.de\/blog\/wp-content\/uploads\/gamma-disk-interface-startdisk-1.jpg 800w, https:\/\/www.jungsi.de\/blog\/wp-content\/uploads\/gamma-disk-interface-startdisk-1-300x225.jpg 300w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><figcaption class=\"wp-element-caption\">Disk Manager<\/figcaption><\/figure>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"600\" height=\"800\" data-id=\"14071\" src=\"https:\/\/www.jungsi.de\/blog\/wp-content\/uploads\/gamma-disk-interface-handbuch-1.jpg\" alt=\"Handbuch\" class=\"wp-image-14071\" srcset=\"https:\/\/www.jungsi.de\/blog\/wp-content\/uploads\/gamma-disk-interface-handbuch-1.jpg 600w, https:\/\/www.jungsi.de\/blog\/wp-content\/uploads\/gamma-disk-interface-handbuch-1-225x300.jpg 225w\" sizes=\"auto, (max-width: 600px) 100vw, 600px\" \/><figcaption class=\"wp-element-caption\">manual<\/figcaption><\/figure>\n<\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">&nbsp;<\/p>","protected":false},"excerpt":{"rendered":"<p>Das Gammadisk-Interface ist ein besonderes Disketteninterface f\u00fcr den Sinclair ZX Spectrum. Das Original ist kaum aufzutreiben und die Nachbauten sind auch nicht mehr erh\u00e4ltlich. So \u2026<\/p>","protected":false},"author":2,"featured_media":13590,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_lmt_disableupdate":"no","_lmt_disable":"","_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_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-13548","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-zx-spectrum","tag-englisch-verfuegbar","tag-hardware","tag-sinclair"],"modified_by":"Jungsi","wp-worthy-pixel":{"ignored":false,"public":"27d2bb5e9a9e47e695c11cc018de8e2b","server":"","url":"https:\/\/vg09.met.vgwort.de\/na\/27d2bb5e9a9e47e695c11cc018de8e2b"},"wp-worthy-type":"normal","jetpack_sharing_enabled":true,"jetpack_featured_media_url":"https:\/\/www.jungsi.de\/blog\/wp-content\/uploads\/gamma-disk-interface.jpg","_links":{"self":[{"href":"https:\/\/www.jungsi.de\/en\/wp-json\/wp\/v2\/posts\/13548","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=13548"}],"version-history":[{"count":5,"href":"https:\/\/www.jungsi.de\/en\/wp-json\/wp\/v2\/posts\/13548\/revisions"}],"predecessor-version":[{"id":44293,"href":"https:\/\/www.jungsi.de\/en\/wp-json\/wp\/v2\/posts\/13548\/revisions\/44293"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.jungsi.de\/en\/wp-json\/wp\/v2\/media\/13590"}],"wp:attachment":[{"href":"https:\/\/www.jungsi.de\/en\/wp-json\/wp\/v2\/media?parent=13548"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.jungsi.de\/en\/wp-json\/wp\/v2\/categories?post=13548"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.jungsi.de\/en\/wp-json\/wp\/v2\/tags?post=13548"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}