Use your TV as a display with Mac. Many televisions can also be used as computer displays. To connect your Mac to your television, you need a video cable that connects your computer’s display port to the video input port on your TV. If you can’t find a cable that connects the ports on your Mac and TV, you may also need an adapter for the cable. Backup your Mac with a portable or desktop hard drive. Safekeep all of your music, photographs, movies and more. Buy online with fast, free shipping. To open the required ports, the SkyBell will need to be assigned a static IP address. Port forward the above ports for the static IP/MAC address for the SkyBell. Please try opening the following ports in your router. SkyBell HD App says there is a problem with my Network; Can I still connect my SkyBell if I.
| Connects to | Macintosh Plus; Macintosh 512K via:
|
|---|---|
| Design firm | Apple Inc. |
| Manufacturer | Apple Inc. |
| Introduced | September 17, 1985 |
| Discontinued | September 1987 |
| Cost | US$1,495 (equivalent to $3,554 in 2019) |
| Type | Hard Disk |
| Memory | 20 MB |
| Connection | Floppy drive port at 500 kbit/s[1][2] |
| Power consumption | 30 W |
| Weight | 7 lbs (3.2 kg) |
| Dimensions | 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.[3]
Features[edit]
The Hard Disk 20 (or HD20, as it was known colloquially) contained a 20 MB 3.5' Rodimehard 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.[2]
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.[4]
History[edit]
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.[5] Apple officially dropped support for the HD 20 with System 6 as well as omitting the necessary ROM code beginning with the Macintosh II.[6] 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[edit]
References[edit]
- ^'The Mac Plus 30 Years On'. January 24, 2016. Retrieved April 20, 2016.
- ^ ab'Apple brand HD20, HD20 SC Info'. 2010. Retrieved April 20, 2016.
- ^Macintosh 128K and 512K: SCSI Hard Drives
- ^Lewis, Peter H (October 8, 1985). 'Peripherals; Apple gives its Macintosh a hard disk'. New York Times. Retrieved December 30, 2007.Cite has empty unknown parameter:
|coauthors=(help) - ^Apple HD-20: How To Convert It Into A SCSI Device
- ^System 6.0.3: Incompatible with Macintosh 512Ke and HD20
External links[edit]
- 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
Information about these and other types of Mac ports is in the specifications for your Mac: Choose Apple menu > About This Mac, click Support, then click Specifications. Or check your Mac user guide.
Thunderbolt 3
Use Thunderbolt 3 with displays and other devices that connect using either a Thunderbolt 3 cable or USB-C cable. You can also connect a USB-C power adapter and cable to charge your notebook computer. If you have a device that doesn't connect to this port, you might be able to use an adapter to connect it.
Office 2011 sp4 for mac os. These Mac models have Thunderbolt 3 ports:
- MacBook Pro introduced in 2016 or later
- MacBook Air introduced in 2018 or later
- iMac introduced in 2017 or later
- iMac Pro (all models)
- Mac mini introduced in 2018
- Mac Pro introduced in 2019
If your Mac notebook or desktop computer has more than one port like this, each port supports ThunderBolt 3 and USB-C.
USB-C
Use USB-C with displays and other devices that connect using a USB-C cable. You can also connect a USB-C power adapter and cable to charge your notebook computer. If you have a device that doesn't connect to this port, you might be able to use an adapter to connect it.
MacBook models introduced in 2015 or later have a single USB-C port. This port doesn't support Thunderbolt devices.
If your Mac has only one port like this, it's a MacBook that supports USB-C but not Thunderbolt.
Thunderbolt
Use Thunderbolt or Thunderbolt 2 with displays and other devices that connect using a Thunderbolt cable.
These Mac models have Thunderbolt or Thunderbolt 2 ports:
- MacBook Pro introduced in 2011 through 2015
- MacBook Air introduced in 2011 through 2017
- Mac mini introduced in 2011 through 2014
- iMac introduced in 2011 through 2015
- Mac Pro introduced in 2013
Thunderbolt and Thunderbolt 2 are not the same as Mini DisplayPort . They have the same shape, but use different symbols on the cable and port. However, this port does support Mini DisplayPort for video output, so you can use a Mini DisplayPort cable to connect a Mini DisplayPort display.
Mini DisplayPort
Use Mini DisplayPort with displays that connect using a Mini DisplayPort cable.
These Mac models have Mini DisplayPort:
- MacBook Pro introduced in late 2008 through 2010
- MacBook Air introduced in late 2008 through 2010
- Mac mini introduced in 2009 and 2010
- iMac introduced in 2009 and 2010
- Mac Pro introduced in 2009 through 2012
Mini DisplayPort is not the same as Thunderbolt or Thunderbolt 2 . Ubuntu remmina. They have the same shape, but use different symbols on the cable and port.
Port Mac Guitars
USB-A
Use USB-A with devices that connect using a USB cable. USB ports are sometimes known by the USB specification of the port, such as USB 2 or USB 3.
Left to right: power, two Thunderbolt, USB-A, and Audio-Out.
HDMI
Use HDMI with displays and TVs that connect using an HDMI cable.
Ethernet
Use Ethernet with networks and devices that connect using an Ethernet (RJ45) cable.
FireWire
Use FireWire with devices that connect using a FireWire 400 or FireWire 800 cable.
SD card
Use the SD card slot with SD, SDHC, SDXC, MMC, and UHS-II media cards, such as those used by digital cameras.
Audio
Use Audio-Out — or — with headphones, speakers, and other audio-output devices that connect using an audio cable that has a 3.5 mm (1/8 inch) audio jack.
Use Audio-In with a microphone or other audio-input device that connects using an audio cable that has a 3.5 mm (1/8 inch) audio jack.
Hd Port For Mac Osx
Power
List Open Ports Mac
Use the power port , if available, to connect your computer to AC power using a MagSafe cable or adapter. This port isn't available on newer Mac notebook computers, which use Thunderbolt 3 or USB-C for power and charging. Learn more about power adapters and cables for Mac notebook computers.