Hard disk 20 - wikipedia Hard disk 20 Hard Disk 20 Model Number : M0135 Connects to Macintosh Plus ; Macintosh 512K via : DB - 19 Connector Design firm Apple Inc. Manufacturer Apple Inc. Introduced September 17, 1985 ( 1985 - 09 - 17 ) Discontinued September 1987 ( 1987 - 09 ) Cost US $1,495 ( equivalent to $3,329 in 2016 ) Type Hard Disk Memory 20 MB Connection Floppy drive port at 500 kbit / s Power consumption 30 W Weight 7 lbs ( 3.2 kg ) 3.1 x 9.7 x 10.5 inches ( 7.9 x 25 x 27 cm ) The Macintosh Hard Disk 20 was the first hard drive developed by Apple Computer specifically for use with the Macintosh 512K. Introduced on September 17, 1985, it was part of Apple 's long awaited solution toward completing the Macintosh Office ( a suite of integrated business hardware & software ) announced in January 1985. It would be over a year more before Apple would release the file server software AppleShare that would link all of the hardware together. By that time the SCSI interface introduced on the Macintosh Plus in January 1986, would accommodate far faster and more efficient hard drives, rendering the Hard Disk 20 virtually obsolete. Contents 1 Features 2 History 3 See also 4 References 5 External links Features The Hard Disk 20 ( or HD20, as it was known colloquially ) contained a 20 MB 3.5 '' Rodime hard disk which provided over 50 times the data storage of the stock 400 kB disk drive. At the time when the average file size was around 10 - 20 kB and due to the vast number of those files the HD 20 could contain, Apple 's original Macintosh File System, which did not allow for directories, would have made organizing those files unwieldy. Therefore, Apple introduced it with a new System and Finder update which included the brand new Hierarchical File System allowing the user to better organize files on such a large volume. As a result, only the Macintosh 512K could access it ; the original Macintosh 128K did not have enough RAM to load the new file system. In fact, even for the Macintosh 512K to use the drive, it required an additional file in the System Folder on a special startup disk which added additional code into memory during startup. An ingenious startup routine also allowed the Mac to check for the presence of a System file on the Hard Disk, switch over to it and eject the startup disk. Unfortunately, the HD 20 could not be used as a startup disk directly without first loading the code from the floppy disk drive. With the release of the Macintosh Plus and the Macintosh 512Ke, both containing the upgraded 128 kB ROM which contained the additional code, the HD 20 could finally be used alone as a startup disk. The drive had a rotational speed of 45.73 rotations / second ( 2744 rpm ) and access time of 85 ms. While other hard drives were available on the market, Apple 's HD 20 was generally preferred mainly because Apple broke their own development rules when they offered it. Originally the Macintosh was designed with two serial ports which were to meet all the expansion needs of the user. It also included a dedicated floppy disk port for one external floppy disk. Most of the hard drives which were available on the market used the slower serial port to transfer data per Apple 's specifications. Apple instead engineered the HD 20 to use the faster floppy disk port, enabling the user to daisy - chain an external floppy disk drive as well as an additional HD 20. With few exceptions, this along with complete compatibility with the new Hierarchical File System, gave Apple an instant edge over the competition. In addition, the HD 20 had a convenient `` zero - footprint '' design which fit precisely underneath the Macintosh, merely elevating it 3 inches, but otherwise taking up no more desk - space. History In 1985, the HD 20 was an important step to solidifying the Macintosh as a true business computer and it was eagerly anticipated following its April announcement. Until Apple 's introduction a year later of the Hard Disk 20SC, the first SCSI drive they manufactured, the HD 20 was the only Apple - manufactured hard drive available for any Macintosh except the Macintosh XL. The HD20 was not compatible with any other Apple computer or other platforms. However, the HD 20 's unique design and position in the marketplace, was quickly outmoded by the advancement of the significantly faster SCSI standard which also debuted with the Macintosh Plus in January 1986. Some third party companies offered a SCSI conversion kit which replaced the controller board thus preserving the user 's investment in the expensive but proprietary Rodime drive. Apple officially dropped support for the HD 20 with System 6 as well as omitting the necessary ROM code beginning with the Macintosh II. Sales of the HD 20 continued to support the Macintosh 512Ke which had no other hard drive options until it was discontinued in late 1987. Apple quickly dropped support for the HD 20 in all of its newer Macs, only to find many business users upgrading their older systems needed a way to transfer data from the unsupported drives to the newer Macs. Only Macs with legacy technology and floppy disk ports, which were eliminated entirely from Macintosh computers in 1991, were able to continue to use the older slower technology. Manufactured in significant numbers for almost two years, The HD 20 remains as one of the few surviving hard drives a stock Macintosh 512K or 512Ke can use. See also List of Apple drives References Jump up ^ `` The Mac Plus 30 Years On ''. 2016 - 01 - 24. Retrieved 2016 - 04 - 20. ^ Jump up to : `` Apple brand HD20, HD20 SC Info ''. 2010. Retrieved 2016 - 04 - 20. Jump up ^ Macintosh 128K and 512K : SCSI Hard Drives Jump up ^ Lewis, Peter H ( October 8, 1985 ). `` Peripherals ; Apple gives its Macintosh a hard disk ''. New York Times. Retrieved December 30, 2007. Jump up ^ Apple HD - 20 : How To Convert It Into A SCSI Device Jump up ^ System 6.0. 3 : Incompatible with Macintosh 512Ke and HD20 External links Hard Disk 20 technical specifications at apple.com at the Wayback Machine ( archived May 16, 2011 ) Mac Systems Compatible with Hard Disk 20 at apple.com Hard Disk 20 tutorial at VintageMacWorld.com Hard Disk 20 Info at Mac512. com 's Classic Macintosh Preservation area at the Wayback Machine ( archived February 20, 2007 ) The M0001 Registry Owners of Vintage Macintosh Apple Macintosh Before System 7 Apple hardware Apple II Family Discontinued Apple I Apple II series Apple III Apple Lisa Mac Desktop Current iMac Mac Pro Mac Mini Discontinued Compact Macintosh Macintosh II LC Quadra Performa Centris Power Macintosh eMac Laptop Current MacBook ( Retina ) MacBook Air MacBook Pro Discontinued Macintosh Portable PowerBook iBook MacBook ( pre-2015 ) Server Discontinued Workgroup Server Network Server Xserve Mac Mini Server Mac Pro Server Devices Current Apple TV Apple Watch Series 1 Series 3 HomePod iPad ( 5th ) iPad Mini 4 iPad Pro iPhone 6S / 6S Plus SE 7 / 7 Plus 8 / 8 Plus X iPod ( Touch ( 6th ) ) Discontinued Interactive Television Box Apple Watch 1st Series 2 iPad 1st 3rd 4th Air Air 2 iPad Mini 1st iPhone 1st 3G 3GS 4S 5 5C 5S 6 / 6 Plus iPod Classic Hi - Fi Mini Nano Shuffle Touch 1st 2nd 3rd 4th 5th Newton Apple Pippin PowerCD Apple QuickTake Accessories Current AirPort AirPort Express Router AirPort Extreme Router AirPort Time Capsule Magic Mouse 2 Magic Trackpad 2 Apple Pencil AirPods Smart Keyboard Remote Siri Remote External SuperDrive Magic Keyboard AirPower Discontinued Displays Thunderbolt Cinema Studio Drives iSight Modems Printers Scanners Mighty Mouse Magic Mouse Magic Trackpad Apple Wireless Keyboard Apple Mobile Processors 64 - bit Apple A7 Apple A8 Apple A8X Apple A9 Apple A9X Apple A10 Apple A10X Apple A11 32 - bit Apple A4 Apple A5 Apple A5X Apple A6 Apple A6X Apple S1 Apple S2 Apple S3 Comparison of Macintosh models Timeline of Apple Inc. products Apple hardware before 1998 Computers Apple Apple I Apple II series II II Plus IIe IIc IIc Plus IIGS Apple III Compact Macintosh 128K 512K 512Ke Plus SE SE / 30 Classic Classic II Color Classic Macintosh II II IIx IIcx IIci IIfx IIsi IIvi IIvx Macintosh LC Macintosh LC LC 500 series Macintosh TV Macintosh Quadra 700 900 950 800 840AV 600 series 610 650 660AV 605 630 PowerBook Macintosh Portable 68k - based PowerBooks 100 series 100 140 170 160 180 150 190 200 series 210 230 500 series PowerPC - based PowerBooks 2300c 5300 1400 3400c 2400c Power Macintosh 4400 and 7220 5000 series 5200 LC and 5300 LC 5260 5400 5500 6000 series 6100 6200 and 6300 6400 6500 7000 series 7100 7200 and 8200 7300 7500 7600 8000 series 8100 8500 8600 9000 series 9500 9600 Power Macintosh G3 Miscellaneous Apple Lisa Macintosh XL Macintosh Performa Macintosh Centris Apple IIe Card ( Macintosh PDS ) Apple Workgroup Server 9150 Apple Network Server Twentieth Anniversary Macintosh Peripherals Displays Monitor III Monitor II AppleColor Composite IIe AppleColor High - Resolution RGB Macintosh Color AudioVision 14 Multiple Scan 14 ColorSync 750 External drives Disk II Macintosh ProFile Hard Disk 20 Hard Disk 20SC AppleCD PowerCD Tape Drive 40SC Input devices Keyboard Desktop Bus Extended Keyboard Adjustable Keyboard Mouse Scanner QuickTake Networking Apple II serial cards Apple Modem LocalTalk Apple Communication slot GeoPort Printers Silentype Dot Matrix Printer Letter Quality Printer ImageWriter LaserWriter 410 Color Plotter Color LaserWriter StyleWriter Newton MessagePad eMate 300 Other Paladin PowerCD Interactive Television Box Pippin Apple hardware since 1998 Retrieved from `` https://en.wikipedia.org/w/index.php?title=Hard_Disk_20&oldid=807787827 '' Categories : Macintosh peripherals Hard disk drives Hidden categories : Use mdy dates from October 2013 Webarchive template wayback links Talk Contents About Wikipedia Français Italiano Edit links This page was last edited on 30 October 2017, at 03 : 25. 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Question: when was the first hard disk is made available for macintosh computers
Answer: September 17, 1985