{"id":43,"date":"2009-06-17T13:53:06","date_gmt":"2009-06-17T20:53:06","guid":{"rendered":"http:\/\/peterwong.net\/blog\/?p=43"},"modified":"2009-06-17T13:53:06","modified_gmt":"2009-06-17T20:53:06","slug":"portable-scsi-drives","status":"publish","type":"post","link":"https:\/\/peterwong.net\/blog\/portable-scsi-drives\/","title":{"rendered":"Portable SCSI Drives"},"content":{"rendered":"<p>About a week ago, I was tinkering with a few external SCSI drives. These external drives are those that draw power from one of the ports in a computer, instead of a wall wart or a direct power plug. In the process, I was humbled to learn a couple of lessons in electronics (I\u2019m a software guy). <\/p>\n<p>A couple of them are enclosures that draw power from an ADB port that is available on the Apple IIgs and older Macintoshes.&#160; The ADB port can be used as a source for +5v.&#160; These enclosures house 2.5\u201d SCSI drives that were normally used in older Apple laptops before they switched to using IDE drives.&#160; These drives just need +5v and do not need the additional +12v source that the bigger 3.5\u201d drives need.<\/p>\n<p><a href=\"\/\/peterwong.net\/blog\/wp-content\/uploads\/2009\/06\/scsienclosureadb11.jpg\"><img loading=\"lazy\" decoding=\"async\" style=\"border-right-width: 0px; display: inline; border-top-width: 0px; border-bottom-width: 0px; border-left-width: 0px\" title=\"SCSIEnclosureADB1-1\" border=\"0\" alt=\"SCSIEnclosureADB1-1\" src=\"\/\/peterwong.net\/blog\/wp-content\/uploads\/2009\/06\/scsienclosureadb11-thumb.jpg\" width=\"244\" height=\"164\" \/><\/a> <\/p>\n<p><a href=\"\/\/peterwong.net\/blog\/wp-content\/uploads\/2009\/06\/scsienclosureadb21.jpg\"><img loading=\"lazy\" decoding=\"async\" style=\"border-right-width: 0px; display: inline; border-top-width: 0px; border-bottom-width: 0px; border-left-width: 0px\" title=\"SCSIEnclosureADB2-1\" border=\"0\" alt=\"SCSIEnclosureADB2-1\" src=\"\/\/peterwong.net\/blog\/wp-content\/uploads\/2009\/06\/scsienclosureadb21-thumb.jpg\" width=\"244\" height=\"164\" \/><\/a> <\/p>\n<\/p>\n<p>One of the 2.5\u201d drives I used was a 1GB Microtech RoadRunner drive.&#160; It is a slim IDE drive bolted to a SCSI-IDE adapter resulting in the same form factor as a regular 2.5\u201d drive.&#160; Kind of helpful to know, since those old 2.5\u201d SCSI drives are getting harder to find.<\/p>\n<p>My first humbling lesson is learning that using the wrong polarity will kill something.&#160; Both enclosures have a barrel attachment to the power line connecting to the ADB port.&#160; Connection looked the same, but the first one was center-positive.&#160; I tried using the same center-positive line in the other enclosure and poof! \u2013 the ADB port in my IIgs just\u2026 died.&#160; Keyboard and mouse stopped working, +5v source not coming out, and so on.&#160; I could have attempted to bring out my soldering stuff, but eventually (remember that I\u2019m not a hardware guy), I ended up sourcing another IIgs motherboard from a fellow Apple enthusiast.<\/p>\n<p>The next couple of SCSI enclosures I worked with were for 3.5\u201d SCSI drives.&#160; As mentioned, 3.5\u201d drives typically need +12v and +5v.&#160; These enclosures were meant to connect to the DB-19 drive connector at the back of the IIgs or a chained external diskette drive.<\/p>\n<p><a href=\"\/\/peterwong.net\/blog\/wp-content\/uploads\/2009\/06\/micronettechnologymp205.jpg\"><img loading=\"lazy\" decoding=\"async\" style=\"border-right-width: 0px; display: inline; border-top-width: 0px; border-bottom-width: 0px; border-left-width: 0px\" title=\"MicroNetTechnologyMP-20-5\" border=\"0\" alt=\"MicroNetTechnologyMP-20-5\" src=\"\/\/peterwong.net\/blog\/wp-content\/uploads\/2009\/06\/micronettechnologymp205-thumb.jpg\" width=\"244\" height=\"164\" \/><\/a> <\/p>\n<p><a href=\"\/\/peterwong.net\/blog\/wp-content\/uploads\/2009\/06\/ncspro85c1.jpg\"><img loading=\"lazy\" decoding=\"async\" style=\"border-right-width: 0px; display: inline; border-top-width: 0px; border-bottom-width: 0px; border-left-width: 0px\" title=\"NCS Pro 85C-1\" border=\"0\" alt=\"NCS Pro 85C-1\" src=\"\/\/peterwong.net\/blog\/wp-content\/uploads\/2009\/06\/ncspro85c1-thumb.jpg\" width=\"244\" height=\"164\" \/><\/a> <\/p>\n<\/p>\n<p>The former is a MicroNet Technology MP-20 with a 20MB SCSI drive.&#160; It has a power cable from a DB-19 plug to a 5-pin DIN connector.&#160; From tracing the lines and referencing the DB-19 pinouts, the 5-pin DIN connector has the following pinout:<\/p>\n<p><a href=\"\/\/peterwong.net\/blog\/wp-content\/uploads\/2009\/06\/din5dm.gif\"><img loading=\"lazy\" decoding=\"async\" style=\"border-right-width: 0px; display: inline; border-top-width: 0px; border-bottom-width: 0px; border-left-width: 0px\" title=\"din5dm\" border=\"0\" alt=\"din5dm\" src=\"\/\/peterwong.net\/blog\/wp-content\/uploads\/2009\/06\/din5dm-thumb.gif\" width=\"57\" height=\"49\" \/><\/a> <\/p>\n<ul>\n<li>Pin 1:&#160; +5v <\/li>\n<li>Pin 2:&#160; Ground <\/li>\n<li>Pin 3:&#160; +12v <\/li>\n<li>Pin 4:&#160; NC <\/li>\n<li>Pin 5:&#160; NC <\/li>\n<\/ul>\n<p>The latter was an NCS Pro 85C with an 80MB SCSI drive.&#160; These were both impressive and expensive back in the days.&#160; For some reason, I don\u2019t have the power cable for this.&#160; The power cable was supposed to connect from the DB-19 port and into the 3-pin mini-DIN socket behind the enclosure.<\/p>\n<p><a href=\"\/\/peterwong.net\/blog\/wp-content\/uploads\/2009\/06\/ncspro85c2.jpg\"><img loading=\"lazy\" decoding=\"async\" style=\"border-right-width: 0px; display: inline; border-top-width: 0px; border-bottom-width: 0px; border-left-width: 0px\" title=\"NCS Pro 85C-2\" border=\"0\" alt=\"NCS Pro 85C-2\" src=\"\/\/peterwong.net\/blog\/wp-content\/uploads\/2009\/06\/ncspro85c2-thumb.jpg\" width=\"244\" height=\"164\" \/><\/a> <\/p>\n<p>Not having been humbled enough with my polarity fiasco, I proceeded to wire up my own cable for the drive.&#160; I had an extra DuoDisk cable that I cut up to get the DB-19 end, but was stumped on the mini-DIN connector.<\/p>\n<p>My first attempt involved noticing that LocalTalk cables (the ones that run the network length, not the ones that attach to the serial port) have those connectors.&#160; After performing once more the ritual dance of sacrificing a very good piece of hardware to make something else, I found out that the LocalTalk cable only had two lines.&#160; Well, duh!&#160; Networking only needs two lines.&#160; The gods weren\u2019t looking favorably at me that day.<\/p>\n<p><a href=\"\/\/peterwong.net\/blog\/wp-content\/uploads\/2009\/06\/ncspro85c4.jpg\"><img loading=\"lazy\" decoding=\"async\" style=\"border-right-width: 0px; display: inline; border-top-width: 0px; border-bottom-width: 0px; border-left-width: 0px\" title=\"NCS Pro 85C-4\" border=\"0\" alt=\"NCS Pro 85C-4\" src=\"\/\/peterwong.net\/blog\/wp-content\/uploads\/2009\/06\/ncspro85c4-thumb.jpg\" width=\"244\" height=\"164\" \/><\/a> <\/p>\n<\/p>\n<p>Off I went to the local Goodwill thrift store looking for a power adapter that uses the 3-pin mini-DIN connector.&#160; Sure enough, I found one (I think it was for a Westell DSL modem).&#160; The source voltage(s) did not matter since I would be cutting the cable.&#160; I had to shave some plastic off the connector before it would snugly fit into the socket at the SCSI enclosure box.<\/p>\n<p><a href=\"\/\/peterwong.net\/blog\/wp-content\/uploads\/2009\/06\/ncspro85c7.jpg\"><img loading=\"lazy\" decoding=\"async\" style=\"border-right-width: 0px; display: inline; border-top-width: 0px; border-bottom-width: 0px; border-left-width: 0px\" title=\"NCS Pro 85C-7\" border=\"0\" alt=\"NCS Pro 85C-7\" src=\"\/\/peterwong.net\/blog\/wp-content\/uploads\/2009\/06\/ncspro85c7-thumb.jpg\" width=\"244\" height=\"164\" \/><\/a> <\/p>\n<p>That\u2019s when I had my second humbling lesson.&#160; I followed the traces wrong and initially had +5v going into the +12v line, and vice versa.&#160; This killed two of my SCSI drives (including the original one inside the NCS Pro 85C) before I realized what was wrong. After switching the two lines, I finally got one of my other IIgs to boot off the external drive.<\/p>\n<p><a href=\"\/\/peterwong.net\/blog\/wp-content\/uploads\/2009\/06\/ncspro85c8.jpg\"><img loading=\"lazy\" decoding=\"async\" style=\"border-right-width: 0px; display: inline; border-top-width: 0px; border-bottom-width: 0px; border-left-width: 0px\" title=\"NCS Pro 85C-8\" border=\"0\" alt=\"NCS Pro 85C-8\" src=\"\/\/peterwong.net\/blog\/wp-content\/uploads\/2009\/06\/ncspro85c8-thumb.jpg\" width=\"244\" height=\"164\" \/><\/a> <\/p>\n<p>You can see in the pictures the two partitions I have in the new SCSI drive I placed inside the enclosure.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>About a week ago, I was tinkering with a few external SCSI drives. These external drives are those that draw power from one of the ports in a computer, instead of a wall wart or a direct power plug. In &hellip; <a href=\"https:\/\/peterwong.net\/blog\/portable-scsi-drives\/\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5],"tags":[10,16,20],"class_list":["post-43","post","type-post","status-publish","format-standard","hentry","category-retrocomputing","tag-apple2","tag-iigs","tag-mac"],"_links":{"self":[{"href":"https:\/\/peterwong.net\/blog\/wp-json\/wp\/v2\/posts\/43","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/peterwong.net\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/peterwong.net\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/peterwong.net\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/peterwong.net\/blog\/wp-json\/wp\/v2\/comments?post=43"}],"version-history":[{"count":0,"href":"https:\/\/peterwong.net\/blog\/wp-json\/wp\/v2\/posts\/43\/revisions"}],"wp:attachment":[{"href":"https:\/\/peterwong.net\/blog\/wp-json\/wp\/v2\/media?parent=43"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/peterwong.net\/blog\/wp-json\/wp\/v2\/categories?post=43"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/peterwong.net\/blog\/wp-json\/wp\/v2\/tags?post=43"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}