Apple Hard Disk 20SC Owner's Guide
The Apple Hard Disk 20SC Owner's Guide is Apple's 1986 manual for the Apple Hard Disk 20SC, part number 030-3138-A. Apple also packed it with the Hard Disk 40SC and 80SC.[1][2] It covers setting the drive up with a Macintosh or with an Apple II fitted with the Apple II SCSI card.
Contents
[edit | edit source]Printed page numbers from the guide's contents list. In the main text, the PDF page number is the printed number plus ten (printed p. 22 is PDF p. 32).[1]
- Chapter 1, Getting Started (p. 1): what you need, handling, inserting the Apple II SCSI card, where to place the hard disk, connecting it, setting the priority switch, starting up with a Macintosh or an Apple II, switching on and off, adding more Hard Disk 20SCs, reinitialising with a Macintosh or an Apple II.
- Chapter 2, Maintenance and Troubleshooting (p. 21): operating environment, cleaning, problem descriptions and solutions, testing the drive with a Macintosh.
- Appendix A, Hard Disk 20SC Specifications (p. 27); Appendix B, Service and Support; Appendix C, Safety Information; Appendix D, Connecting Three or Four Hard Disk 20SCs to an Apple II; glossary and index.
What it settles
[edit | edit source]- Placement: keep the vents at the sides and back clear; beside a Macintosh, put the drive on the right, away from the power supply and video circuitry; do not put a monitor on it (p. 4, PDF p. 14).
- With two or more drives on a Macintosh, switch them all on at least 10 seconds before the Macintosh (p. 23, PDF p. 33).
- The Installer's drive test takes about 4 minutes and does not affect the data on the disk; Apple suggests running it every month or so (pp. 24-25, PDF pp. 34-35).
- Specifications: 85-270 V AC, 60 W, 20 MB, 532 bytes per block, 39,360 blocks, start-up 9 s, spin-down 20 s, maximum weight 3.63 kg (p. 27, PDF p. 37). Apple's Tech Info Library article 1931 gives the block size as 512 bytes.
What this manual does not contain
[edit | edit source]It is an owner's guide. It tells owners never to remove the cover, because the drive holds high-voltage components that keep their charge after switch-off (p. 22, PDF p. 32), and it has no take-apart procedure, parts list or schematic. For those see Apple Service Technical Procedures Cross Family Peripherals Volume One and Apple External Hard Drive SC Service Source.
Apple's Tech Info Library article 662 notes that the terminator diagram in the owner's guide differs from Apple's SCSI Cable System manual, and recommends the cable-system arrangement.[3]
Pages that cite this document
[edit | edit source]- Apple Hard Disk 20SC
- Apple Hard Disk SC General Maintenance
- Apple Hard Disk SC Troubleshooting Guide
- Apple Hard Disk SC Capacitor Replacement Guide
Download: Apple Hard Disk 20SC Owners Guide 1986.pdf
References
[edit | edit source]- ↑ 1.0 1.1 Apple Computer, Apple Hard Disk 20SC Owner's Guide (030-3138-A, 1986), 52 PDF pages, scanned without a text layer. Hosted as File:Apple Hard Disk 20SC Owners Guide 1986.pdf; from http://www.cvxmelody.net/ (retrieved 2026-10-04). The part number is from the PDF's document title.
- ↑ Apple Computer, Apple Hard Disk SC Packing List, B030-3139-C, archive.org item apple-hard-disk-sc-packing-list-b030-3139-c.
- ↑ Apple Computer, "Hard Disk 20SC: Connecting a terminator", Tech Info Library article 662, revised 29 September 1990, in the archive.org collection Apple's Technical Information Library Articles, https://archive.org/details/APPLE_TIL_ARTICLES, file TIL00001_to_TIL60496.zip.