{"id":21806,"date":"2025-07-21T13:19:47","date_gmt":"2025-07-21T17:19:47","guid":{"rendered":"https:\/\/carleton.ca\/scs\/?page_id=21806"},"modified":"2026-06-22T14:49:46","modified_gmt":"2026-06-22T18:49:46","slug":"vin93","status":"publish","type":"page","link":"https:\/\/carleton.ca\/scs\/vintage-computing\/item\/vin93\/","title":{"rendered":"Tandy Color Computer 3 (CoCo 3)"},"content":{"rendered":"\n<section class=\"w-screen px-6 cu-section cu-section--white ml-offset-center md:px-8 lg:px-14\">\n    <div class=\"space-y-6 cu-max-w-child-5xl  md:space-y-10 cu-prose-first-last\">\n\n            <div class=\"cu-textmedia flex flex-col lg:flex-row mx-auto gap-6 md:gap-10 my-6 md:my-12 first:mt-0 max-w-5xl\">\n        <div class=\"justify-start cu-textmedia-content cu-prose-first-last\" style=\"flex: 0 0 100%;\">\n            <header class=\"font-light prose-xl cu-pageheader md:prose-2xl cu-component-updated cu-prose-first-last\">\n                                    <h1 class=\"cu-prose-first-last font-semibold !mt-2 mb-4 md:mb-6 relative after:absolute after:h-px after:bottom-0 after:bg-cu-red after:left-px text-3xl md:text-4xl lg:text-5xl lg:leading-[3.5rem] pb-5 after:w-10 text-cu-black-700 not-prose\">\n                        Tandy Color Computer 3 (CoCo 3)\n                    <\/h1>\n                \n                                \n                            <\/header>\n\n                    <\/div>\n\n            <\/div>\n\n    <\/div>\n<\/section>\n\n\n\n<div class=\"wp-block-buttons is-layout-flex wp-block-buttons-is-layout-flex\">\n<div class=\"wp-block-button is-style-fill\"><a class=\"wp-block-button__link wp-element-button\" href=\"https:\/\/carleton.ca\/scs\/vintage-computing\/item\">Vintage Computing Collection<\/a><\/div>\n<\/div>\n\n\n\n<h2 id=\"tandy-color-computer-3-coco-3\" class=\"wp-block-heading\">Tandy Color Computer 3 (CoCo 3)<\/h2>\n\n\n\n<p>[Vin93]<\/p>\n\n\n\n<figure class=\"wp-block-image alignright\"><a href=\"https:\/\/carleton.ca\/scs\/wp-content\/uploads\/sites\/260\/PXL_20260204_194903763-scaled.jpg\"><img loading=\"lazy\" decoding=\"async\" width=\"400\" height=\"300\" src=\"https:\/\/carleton.ca\/scs\/wp-content\/uploads\/sites\/260\/PXL_20260204_194903763-400x300.jpg\" alt=\"Tandy Color Computer 3 (CoCo 3)\" class=\"wp-image-23393\" srcset=\"https:\/\/carleton.ca\/scs\/wp-content\/uploads\/sites\/260\/PXL_20260204_194903763-400x300.jpg 400w, https:\/\/carleton.ca\/scs\/wp-content\/uploads\/sites\/260\/PXL_20260204_194903763-160x120.jpg 160w, https:\/\/carleton.ca\/scs\/wp-content\/uploads\/sites\/260\/PXL_20260204_194903763-240x180.jpg 240w, https:\/\/carleton.ca\/scs\/wp-content\/uploads\/sites\/260\/PXL_20260204_194903763-768x577.jpg 768w, https:\/\/carleton.ca\/scs\/wp-content\/uploads\/sites\/260\/PXL_20260204_194903763-1536x1153.jpg 1536w, https:\/\/carleton.ca\/scs\/wp-content\/uploads\/sites\/260\/PXL_20260204_194903763-2048x1538.jpg 2048w, https:\/\/carleton.ca\/scs\/wp-content\/uploads\/sites\/260\/PXL_20260204_194903763-800x600.jpg 800w, https:\/\/carleton.ca\/scs\/wp-content\/uploads\/sites\/260\/PXL_20260204_194903763-360x270.jpg 360w\" sizes=\"auto, (max-width: 400px) 100vw, 400px\" \/><\/a><\/figure>\n\n\n\n<p>The Tandy Color Computer 3 (CoCo 3), released in 1986, was a significant home computer in North America, known for its backward compatibility, upgraded memory (128KB expandable to 512KB), and enhanced graphics via the custom GIME chip<span class=\"whitespace-nowrap\">.<\/span>&nbsp;Its claim to fame was offering advanced color graphics and multitasking capabilities on the Motorola 6809E processor at a time when 8-bit machines were becoming obsolete, carving a devoted niche among enthusiasts and educational users<span class=\"whitespace-nowrap\">.<\/span> While never rivalling sales of giants like Commodore or Apple, the CoCo 3 enjoyed moderate popularity in north America.<\/p>\n\n\n\n<p>&nbsp;<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Manufacturer<\/strong>: Tandy Corporation (Radio Shack)<\/li>\n\n\n\n<li><strong>Type<\/strong>: Home computer<\/li>\n\n\n\n<li><strong>Released<\/strong>: 1986<\/li>\n\n\n\n<li><strong>Cost at release<\/strong>: USD $219 (CAD ~$750 adjusted for inflation)<\/li>\n\n\n\n<li><strong>Cost of a full system<\/strong>: USD $665 (CAD ~$2,250 adjusted for inflation<\/li>\n\n\n\n<li><strong>MIPS<\/strong>: 0.5 (500 KIPS)<\/li>\n<\/ul>\n\n\n\n<h3 id=\"hardware-specifications\" class=\"wp-block-heading\"><span class=\"NormalTextRun SCXW169789978 BCX0\">Hardware Specifications<\/span><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>CPU<\/strong>: Motorola 68B09E, 1.79MHz (switchable between 0.89MHz and 1.79MHz)<\/li>\n\n\n\n<li><strong>RAM<\/strong>: 128KB standard, expandable to 512KB (third-party upgrades up to 2MB)<\/li>\n\n\n\n<li><strong>ROM<\/strong>: 32KB, featuring Microsoft Extended Color BASIC with enhancements by Microware<\/li>\n\n\n\n<li><strong>Graphics<\/strong>: Custom GIME (Graphics Interrupt Memory Enhancement) chip. Resolutions up to 640\u00d7225 pixels (machine code). Up to 16 simultaneous colors from a 64-color palette<\/li>\n\n\n\n<li><strong>Text Modes<\/strong>: Up to 80\u00d728 characters per screen<\/li>\n\n\n\n<li><strong>Sound<\/strong>: 1-channel (6-bit DAC), output through television<\/li>\n\n\n\n<li><strong>Storage<\/strong>: Cassette interface and support for floppy disk drives (using \u2018Program Pak\u2019 cartridges)<\/li>\n\n\n\n<li><strong>Input\/Outputs<\/strong>: 2 joystick ports, Analog RGB, composite, and TV outputs, RS-232 serial port, Cartridge expansion slot<\/li>\n\n\n\n<li><strong>Keyboard<\/strong>: Full-stroke, 53-key keyboard with added arrow keys, CTRL, ALT, F1, and F2<\/li>\n\n\n\n<li><strong>Weight<\/strong>: About 2.8kg (6.2lbs)<\/li>\n<\/ul>\n\n\n\n<h3 id=\"operating-system-programming-languages\" class=\"wp-block-heading\"><span class=\"TextRun SCXW50331614 BCX0\" lang=\"EN-US\" xml:lang=\"EN-US\" data-contrast=\"auto\"><span class=\"NormalTextRun SCXW50331614 BCX0\">Operating System &amp; Programming Languages<\/span><\/span><span class=\"EOP SCXW50331614 BCX0\" data-ccp-props=\"{&quot;335559685&quot;:0}\">&nbsp;<\/span><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>O\/S<\/strong>: Microsoft Extended Color BASIC (with Microware Super Extended Color BASIC enhancements). Optional: OS-9 Level II, a multitasking and multiuser operating system, was widely used for more advanced applications such as programming, word processing, and database management.<\/li>\n\n\n\n<li><strong>Programming Languages<\/strong>:\n<ul class=\"wp-block-list\">\n<li>BASIC:\n<ul class=\"wp-block-list\">\n<li>Color BASIC (built-in)<\/li>\n\n\n\n<li>Extended Color BASIC (built-in)<\/li>\n\n\n\n<li>Super Extended Color BASIC (Microware extension, built-in)<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li>Assembly Language (Machine Code): Supported directly via the Motorola 6809E processor<\/li>\n\n\n\n<li>C: Available under OS-9 and other development environments<\/li>\n\n\n\n<li>Pascal: Third-party Pascal implementations were available, especially under OS-9<\/li>\n\n\n\n<li>FORTRAN: Available for the system when using OS-9<\/li>\n\n\n\n<li>Logo (educational)<\/li>\n\n\n\n<li>Forth<\/li>\n\n\n\n<li>BASIC09 (under OS-9)<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<h3 id=\"notables\" class=\"wp-block-heading\">Notables<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Widely known as &#8220;CoCo 3&#8221; among enthusiasts.<\/li>\n\n\n\n<li>One of the few home computers using the Motorola 6809E, considered one of the most advanced 8-bit CPUs for its time.<\/li>\n\n\n\n<li>Introduced the proprietary GIME (Graphics Interrupt Memory Enhancement) chip for improved graphics and memory management.<\/li>\n\n\n\n<li>Could run almost all software and use most peripherals from the earlier CoCo 1 and 2, making it a standout for upgradeability in the home computer era.<\/li>\n\n\n\n<li>OS-9 Level II brought full preemptive multitasking and multiuser support; this was rare for affordable home computers in the 1980s.<\/li>\n\n\n\n<li>All RAM Mode: Used an \u201call RAM\u201d technique to sidestep software licensing constraints, copying ROM routines to RAM and patching in new features\u2014unusual for its era.<\/li>\n<\/ul>\n\n\n\n<p><strong>Donated by<\/strong>: Dr. Arlen Michaels<\/p>\n\n\n\n<div class=\"wp-block-buttons is-layout-flex wp-block-buttons-is-layout-flex\">\n<div class=\"wp-block-button is-style-fill\"><a class=\"wp-block-button__link wp-element-button\" href=\"https:\/\/carleton.ca\/scs\/vintage-computing\/item\">Vintage Computing Collection<\/a><\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>Tandy Color Computer 3 (CoCo 3) [Vin93] The Tandy Color Computer 3 (CoCo 3), released in 1986, was a significant home computer in North America, known for its backward compatibility, upgraded memory (128KB expandable to 512KB), and enhanced graphics via the custom GIME chip.&nbsp;Its claim to fame was offering advanced color graphics and multitasking capabilities [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":0,"parent":19704,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_acf_changed":false,"_cu_dining_location_slug":"","footnotes":"","_links_to":"","_links_to_target":""},"cu_page_type":[90,123],"class_list":["post-21806","page","type-page","status-publish","hentry","cu_page_type-vintage-computing","cu_page_type-vintage-inventory"],"acf":{"cu_post_thumbnail":""},"_links":{"self":[{"href":"https:\/\/carleton.ca\/scs\/wp-json\/wp\/v2\/pages\/21806","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/carleton.ca\/scs\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/carleton.ca\/scs\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/carleton.ca\/scs\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/carleton.ca\/scs\/wp-json\/wp\/v2\/comments?post=21806"}],"version-history":[{"count":4,"href":"https:\/\/carleton.ca\/scs\/wp-json\/wp\/v2\/pages\/21806\/revisions"}],"predecessor-version":[{"id":25135,"href":"https:\/\/carleton.ca\/scs\/wp-json\/wp\/v2\/pages\/21806\/revisions\/25135"}],"up":[{"embeddable":true,"href":"https:\/\/carleton.ca\/scs\/wp-json\/wp\/v2\/pages\/19704"}],"wp:attachment":[{"href":"https:\/\/carleton.ca\/scs\/wp-json\/wp\/v2\/media?parent=21806"}],"wp:term":[{"taxonomy":"cu_page_type","embeddable":true,"href":"https:\/\/carleton.ca\/scs\/wp-json\/wp\/v2\/cu_page_type?post=21806"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}