Hard Disk 20

Hard Disk 20
Connects toMacintosh Plus;
Macintosh 512K via:
  • DB-19 Connector
Design firmApple Inc.
ManufacturerApple Inc.
IntroducedSeptember 17, 1985 (1985-09-17)
DiscontinuedSeptember 1987 (1987-09)
CostUS$1,495 (equivalent to $4,235 in 2023)
TypeHard Disk
Memory20 MB
ConnectionFloppy drive port at 500 kbit/s[1][2]
Power consumption30 W
Weight7 lbs (3.2 kg)
Dimensions3.1 x 9.7 x 10.5 inches (7.9 x 25 x 27 cm)

The Macintosh Hard Disk 20 is 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 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.[3]

  1. ^ "The Mac Plus 30 Years On". January 24, 2016. Archived from the original on April 25, 2016. Retrieved April 20, 2016.
  2. ^ "Apple brand HD20, HD20 SC Info". 2010. Archived from the original on February 3, 2016. Retrieved April 20, 2016.
  3. ^ "Macintosh 128K and 512K: SCSI Hard Drives". Archived from the original on September 27, 2022. Retrieved April 22, 2015.