Apple Hard Disk 20 Service Source: Difference between revisions
P4: turn document holder into a real documentation page (verification drive) |
Copyedit; drop unsupported 'plastic is brittle' reason; point to the newly hosted HD20 Technical Procedures and note the fan discrepancy |
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The '''Hard Disk 20''' volume of Apple's ''Service Source'' is a | The '''Hard Disk 20''' volume of Apple's ''Service Source'' is a 19-page take-apart document for the Apple Hard Disk 20, the 20 MB drive that connects to the Macintosh external floppy port over Apple's Directly Connected Disk protocol; it is not a SCSI device. The PDF was created on 5 December 1995. | ||
== Contents == | == Contents == | ||
* | * Take Apart (PDF pp. 2-17): Cover, Controller Board, Bottom Shield, Fan, Power Supply, Hard Drive. Each procedure lists the parts to remove first, so they run in that order. | ||
* | * Exploded View (PDF pp. 18-19). | ||
The cover procedure uses a Torx screwdriver, a jeweller's screwdriver to release the tabs and the Macintosh pull-apart tool, with the caution "Do not use a screwdriver to separate the case." The hard drive procedure warns that the drive cable is not a standard ribbon cable and that an incorrect cable will seriously damage the drive or the controller board. | |||
== What this manual does not contain == | == What this manual does not contain == | ||
There is | There is no Basics, Specifications, Troubleshooting or Adjustments chapter: no capacity or transfer figures, no supply voltages, no symptom chart, no parts list, no schematic and no component values. It does not describe the DCD interface; the [[Apple Directly Connected Disks Specification]] gives the DB-19 pinout, the 489.58 kbit/s line rate and the fact that the drive is self-powered. | ||
Apple's earlier ''Hard Disk 20 Technical Procedures'' (1985-86), also hosted here as [[:File:Apple Hard Disk 20 Technical Procedures.pdf]], has what this volume lacks: setup and switch-off procedure, diagnostics, a troubleshooting flowchart, startup and daisy-chaining problems and a parts list with Apple part numbers. The two differ on the fan: this volume gives two fan screws and the rotation arrow pointing down, the Technical Procedures four screws and the arrow pointing up. Both put the air-flow arrow to the rear of the case. | |||
== Pages that cite this document == | == Pages that cite this document == | ||
* [[Apple Hard Disk 20 Maintenance]] | * [[Apple Hard Disk 20 Maintenance]]: the disassembly order and Apple's cautions. | ||
* [[Apple Directly Connected Disks Specification]] | * [[Apple Directly Connected Disks Specification]] | ||
Latest revision as of 13:03, 30 September 2026
The Hard Disk 20 volume of Apple's Service Source is a 19-page take-apart document for the Apple Hard Disk 20, the 20 MB drive that connects to the Macintosh external floppy port over Apple's Directly Connected Disk protocol; it is not a SCSI device. The PDF was created on 5 December 1995.
Contents
[edit | edit source]- Take Apart (PDF pp. 2-17): Cover, Controller Board, Bottom Shield, Fan, Power Supply, Hard Drive. Each procedure lists the parts to remove first, so they run in that order.
- Exploded View (PDF pp. 18-19).
The cover procedure uses a Torx screwdriver, a jeweller's screwdriver to release the tabs and the Macintosh pull-apart tool, with the caution "Do not use a screwdriver to separate the case." The hard drive procedure warns that the drive cable is not a standard ribbon cable and that an incorrect cable will seriously damage the drive or the controller board.
What this manual does not contain
[edit | edit source]There is no Basics, Specifications, Troubleshooting or Adjustments chapter: no capacity or transfer figures, no supply voltages, no symptom chart, no parts list, no schematic and no component values. It does not describe the DCD interface; the Apple Directly Connected Disks Specification gives the DB-19 pinout, the 489.58 kbit/s line rate and the fact that the drive is self-powered.
Apple's earlier Hard Disk 20 Technical Procedures (1985-86), also hosted here as File:Apple Hard Disk 20 Technical Procedures.pdf, has what this volume lacks: setup and switch-off procedure, diagnostics, a troubleshooting flowchart, startup and daisy-chaining problems and a parts list with Apple part numbers. The two differ on the fan: this volume gives two fan screws and the rotation arrow pointing down, the Technical Procedures four screws and the arrow pointing up. Both put the air-flow arrow to the rear of the case.
Pages that cite this document
[edit | edit source]- Apple Hard Disk 20 Maintenance: the disassembly order and Apple's cautions.
- Apple Directly Connected Disks Specification
Download: Hard disk 20.pdf