{"id":7786,"date":"2015-10-07T00:01:09","date_gmt":"2015-10-07T07:01:09","guid":{"rendered":"http:\/\/www.wambooli.com\/blog\/?p=7786"},"modified":"2015-10-09T06:59:11","modified_gmt":"2015-10-09T13:59:11","slug":"a-trip-down-port-lane","status":"publish","type":"post","link":"https:\/\/www.wambooli.com\/blog\/?p=7786","title":{"rendered":"A Trip Down Port Lane"},"content":{"rendered":"

Back in the early days of the PC, it seemed like each peripheral used its own interface.
\n
\nFigure 1 is from the 4th Edition of PCs For Dummies<\/em>, published in 1996. It illustrates the connectors common to a PC of that era.<\/p>\n

\"Figure

Figure 1. Common connectors on a mid-1990s vintage PC.<\/p><\/div>\n

Any PC port or plug-in-hole-thing formerly available but no longer common, is known as a legacy port<\/em>. Today, legacy technology is trivia, but at one time, knowing these connections and holes was an important part of using a PC. For a trip down memory-mapped lane, consider these one time vital but now legacy ports:<\/p>\n

Keyboard.<\/strong> The original PC featured a dedicated keyboard port with only 5 holes. Next to it on the very first IBM PC was a cassette recorder port — the old CAS:<\/code> device. That’s right, you could use the BASIC programming language on the original IBM PC model 5150 to save and fetch data to a cassette tape. And, yes, I actually did that once or twice.<\/p>\n

Serial or RS-232 ports.<\/strong> These ports existed on early PCs as a common form of computer expansion, although the only two items people typically connected were a modem or a computer mouse. The port changed size from 25-pins down to 9-pins. You could also connect a printer or a scanner to the port, and I remember the publishing house I once worked at had a high-speed serial printer.<\/p>\n

Printer\/Centronics\/Parallel ports.<\/strong> The original PC didn’t come with a printer port. The port was part of the video expansion hardware, which is a weird combination. The printer port eventually proved to be pretty flexible because it was possible to chain several devices together. That popularity instantly waned when the USB standard was introduced.<\/p>\n

Joystick port.<\/strong> This oddball port could host a joystick, but it was known in the IBM PC technical manual as the A-to-D port, for Analog to Digital. In theory, you could connect a variety of analog devices to the port and it was frequently used for experimentation. it was also one of the first legacy ports to vanish from the PC’s rear end.<\/p>\n

VGA Port.<\/strong> For centuries this port was the location where you connected a color monitor. The VGA port was the same size as the 9-pin serial port, but it featured 25-pins. Still, people would jab one cable into the wrong connector all the time. The VGA port is the only legacy port that still appears on PCs today.<\/p>\n

Keyboard & Mouse.<\/strong> The original keyboard port was replaced by another, smaller keyboard port with the introduction of the IBM PS\/2 system in 1987. Both the keyboard and mouse ports looked identical, so they were color coded: Green for the mouse and purple for the keyboard. Or was it the other way around? Whatever.<\/p>\n

Other legacy port standards littered the PC landscape for several generations of PCs. These include IEEE or 1394 ports (aka “Firewire”), eSATA, SCSI, S Video, Infrared, and a few other hokey and silly ports. Things are so much more sane these days.<\/p>\n","protected":false},"excerpt":{"rendered":"

Gone by not forgotten ports and holes of the past.<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[15],"class_list":["post-7786","post","type-post","status-publish","format-standard","hentry","category-main","tag-pc"],"_links":{"self":[{"href":"https:\/\/www.wambooli.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/7786","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.wambooli.com\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.wambooli.com\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.wambooli.com\/blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.wambooli.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=7786"}],"version-history":[{"count":4,"href":"https:\/\/www.wambooli.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/7786\/revisions"}],"predecessor-version":[{"id":7798,"href":"https:\/\/www.wambooli.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/7786\/revisions\/7798"}],"wp:attachment":[{"href":"https:\/\/www.wambooli.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=7786"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.wambooli.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=7786"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.wambooli.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=7786"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}