Apple Hard Disk 40SC
| Apple Hard Disk 40SC | |
|---|---|
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|
| Apple's drawing of the case shared by the 20SC, 40SC, 80SC and 160SC | |
| Manufacturer | Apple Computer, Inc. |
| Type | External SCSI hard disk drive |
| Discontinued | May 1993[1] |
| Interface | SCSI, 50-pin |
| Compatible | Macintosh with a SCSI port; Apple IIe and Apple IIGS with an Apple II SCSI card |
| Dimensions | 246 × 78.5 × 266 mm (9.7 × 3.1 × 10.5 in) |
| Weight | 4 kg (9 lb) |
| Model | M2644 |
| Power | 85-270 V AC, 47-64 Hz, 60 W maximum |
| Storage | 39,333K formatted |
The Apple Hard Disk 40SC (part number M2644) is Apple's 40 MB external SCSI hard disk, a member of the Apple Hard Disk SC range with the 20SC, 80SC and 160SC.[1][2] It uses the same case, power supply and fan as the other three, with its own case bottom (630-5335) and drive mechanism.[3] The case, take-apart and repair are covered on Apple Hard Disk SC General Maintenance and Apple Hard Disk SC Troubleshooting Guide.
Specifications
[edit | edit source]| Item | Value |
|---|---|
| Formatted capacity | 39,333K (with HD Setup 1.5) |
| Disk diameter | 5.25 in |
| Data surfaces | 4, one head per surface |
| Bytes per block | 512 |
| Logical allocation block | 1,024 bytes |
| Total blocks | 78,246 |
| Sectors per track | 32 |
| Average seek time | 30 ms |
| Head actuator | Rotary voice coil[4] |
| Transfer rate | Up to 1.25 MB/s |
| Rotational speed | 3,662 rpm |
| Start-up and spin-down | 13 s and 18 s |
| Line voltage | 85-270 V AC, 47-64 Hz |
| Maximum power | 60 W |
| Operating temperature | 10-40 °C (50-104 °F) |
| Storage temperature | 0-50 °C |
| Relative humidity | 20-80 %, non-condensing |
| Height × width × depth | 78.5 × 246 × 266 mm (3.1 × 9.7 × 10.5 in) |
| Weight | 4 kg (9 lb) |
Mechanisms
[edit | edit source]Apple's specification article gives a 5.25-inch disk for the external 40SC.[1] Apple also had 3.5-inch 40 MB mechanisms, and its service manual lists both sizes as usable with the Macintosh, Apple IIe and Apple IIGS.[3] The 5.25-inch 40 MB hard disk assembly is 661-0391 in Apple's parts list.[3]
Apple's 1989 service procedures describe two faults on these mechanisms:
- Some Hard Disk 40SC and 80SC drives stop starting up after a period of use: there is none of the normal whine at start-up and the computer does not see the drive. Apple's cure was a new hard disk assembly. To recover the data first, Apple's procedure holds the hard disk assembly with its board facing the technician and turns it counter-clockwise in one quick, sharp motion, which should let it start.[3]
- Some 3.5-inch Quantum 40 MB and 80 MB mechanisms with variation codes 0032, 0034 and 0058 boot intermittently, showing a disk icon with a flashing question mark or a "Cannot Load Finder" message. Apple replaced their ROM (version 7.9 01) with PROM version TA.2 01, part 341-0768.[3]
The procedures are on Apple Hard Disk SC Troubleshooting Guide.
Using it with an Apple II
[edit | edit source]ProDOS cannot address more than 32 MB, so an Apple II with an Apple II SCSI card cannot use the whole 40SC as one volume.[5] Apple's service manual says drives up to and including the 80SC can be partitioned to use all of their capacity, with up to four partitions when the SCSI card is in slot 5.[3]
Documentation
[edit | edit source]- Apple Service Technical Procedures Cross Family Peripherals Volume One: Apple's service procedures for the SCSI hard disk drives.[3]
- Apple Hard Disk 20SC Owner's Guide: the owner's guide Apple packed with the 40SC.[2]
- Apple External Hard Drive SC Service Source: the later take-apart volume for the 20SC to 160SC case.
Related pages
[edit | edit source]- Apple Hard Disk SC General Maintenance
- Apple Hard Disk SC Troubleshooting Guide
- Apple Hard Disk SC Capacitor Replacement Guide
- Apple Hard Disk 20SC
- Apple Hard Disk 80SC
- Apple Hard Disk 160SC
References
[edit | edit source]- ↑ 1.0 1.1 1.2 1.3 Apple Computer, "Hard Disk 40SC and Hard Disk 80SC: Specs (Discontinued 5/93)", Tech Info Library article 2166, reviewed 29 March 1988, revised 14 September 1993, in the archive.org collection Apple's Technical Information Library Articles, https://archive.org/details/APPLE_TIL_ARTICLES, file TIL00001_to_TIL60496.zip. Source for the part number M2644, every figure in the specification table except the head actuator, and the May 1993 discontinuation.
- ↑ 2.0 2.1 Apple Computer, Apple Hard Disk SC Packing List, B030-3139-C, archive.org item apple-hard-disk-sc-packing-list-b030-3139-c (retrieved 2026-10-04): the same box contents for the 20SC, 40SC, 80SC and 80SC with A/UX, including the Hard Disk 20SC Owner's Guide, the Hard Disk SC Setup disk, a SCSI system cable and a SCSI terminator.
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 3.6 Apple Computer, Apple Service Technical Procedures, Cross Family Peripherals, Volume One (PN 072-0230, 1991), SCSI Hard Disk Drives chapter, hosted as File:Apple Service Technical Procedures Cross Family Peripherals Volume One Apr 1991.pdf and described at Apple Service Technical Procedures Cross Family Peripherals Volume One. Basics, p. 1.3 (PDF p. 178): drive matrix; p. 1.10 (PDF p. 185): partitioning on the Apple II; Additional Procedures, pp. 6.4-6.8 (PDF pp. 249-253): Hard Disk Startup Problem and Macintosh Hard Disk 40SC/80SC Upgrade; Illustrated Parts List, IPL.3 and IPL.7 (PDF pp. 256, 260).
- ↑ Apple Computer, "Apple HD SC: Specifications (Discontinued)", Tech Info Library article 2791, created 28 April 1988, APPLE_TIL_ARTICLES collection (archive.org), file TIL00001_to_TIL60496.zip. Source for the rotary voice-coil actuators and 30 ms access of the HD-40 SC and HD-80 SC.
- ↑ Apple Computer, "ProDOS: Limited to 32 megabyte access on HD40SC and HD80SC", Tech Info Library article 2153, reviewed 2 March 1987, APPLE_TIL_ARTICLES collection (archive.org), file TIL00001_to_TIL60496.zip.