Apple PowerBook Duo Dock
| PowerBook Duo Dock | |
|---|---|
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|
| A PowerBook Duo docked under an external display (Dpaanlka, public domain) | |
| Manufacturer | Apple Computer |
| Type | Docking station |
| Release date | 19 October 1992 (Duo Dock); 16 May 1994 (Duo Dock II); 15 May 1995 (Duo Dock Plus) |
| Interface | 152-pin processor-direct slot docking connector |
| Compatible | PowerBook Duo 210, PowerBook Duo 230, PowerBook Duo 250, PowerBook Duo 270c, PowerBook Duo 280 and 280c, PowerBook Duo 2300 |
| Weight | 13.1 lb (5.95 kg) (Duo Dock, no hard drive) |
| Model | M7779 (Duo Dock) |
| Power | Internal universal supply, 75 W continuous |
| Part number | M4179LL/A, M2631LL/A (Duo Dock); M1865LL/A (Duo Dock II); M4219LL/A (Duo Dock Plus) |
The PowerBook Duo Dock is Apple's full-size docking station for the PowerBook Duo. The closed Duo slides into a slot in the front and a motor draws it onto the dock's 152-pin processor-direct connector, after which the Duo runs as a desktop Macintosh with an external display, keyboard and mouse, a built-in floppy drive, two NuBus slots and a bay for a second hard drive.[1] Apple sold three versions: the original Duo Dock (1992), the Duo Dock II (1994) and the Duo Dock Plus (1995).[2] The docks share a chassis, power supply and release mechanism, and Apple services all three from one Service Source.[3] Maintenance, faults and the power supply recap are covered on Apple PowerBook Duo Dock General Maintenance, Apple PowerBook Duo Dock Troubleshooting and Apple PowerBook Duo Dock Capacitor Replacement Guide.
Versions
[edit | edit source]| Duo Dock | Duo Dock II | Duo Dock Plus | |
|---|---|---|---|
| Math coprocessor | 68882 at 25 MHz, optional (socketed) | 68882 at 33 MHz with 32K cache | None |
| Video RAM | 512K soldered, plus one 512K VRAM SIMM slot | 1 MB soldered, no slot | 1 MB soldered, no slot |
| Ethernet | None | Built in | Built in |
| Logic board | 661-1657 | 661-1707 | 661-0975 |
| Top cover | 922-0519 | 815-0459 | 815-0459 |
Duo Dock
[edit | edit source]The original Duo Dock was sold bare or in a configuration that added a 230 MB hard drive, a 25 MHz 68882 math coprocessor, a 512K VRAM SIMM and an ADB Mouse II. On the bare dock the drive, coprocessor and SIMM are options.[4] EveryMac gives the order numbers as M4179LL/A for the bare dock and M2631LL/A for the configuration with the FPU and hard drive.[5] Apple's February 1993 Apple Facts lists the Math Coprocessor Kit, the Ethernet NB Card and the VRAM Expansion Kit (one 512K SIMM) as its accessories, and says it supports displays of up to 50 lb on top.[6]
The 270c and the later colour Duos are thicker than the 210 and 230. The Duo FAQ of July 1994 says Apple began selling the Duo Dock with a larger hood for the 270c, sold the hood separately for existing docks, and that the new hood can be recognised by a dust cover over the PowerBook slot.[7]
Duo Dock II
[edit | edit source]Apple introduced the Duo Dock II on 16 May 1994.[2] It has the 68882 at 33 MHz with a 32K RAM cache, 1 MB of soldered VRAM and on-board Ethernet. The VRAM cannot be expanded.[4][8] Apple's October 1994 Apple Facts says the coprocessor and cache benefit only Duos with a 68030 processor.[9] An original Duo Dock can be converted into a Duo Dock II by fitting a Duo Dock II logic board and cover. Apple sold the two parts individually; there was no upgrade kit.[8]
Duo Dock Plus
[edit | edit source]The Duo Dock Plus followed on 15 May 1995.[2] Apple's Service Source describes it as a Duo Dock II without the FPU and cache.[4] EveryMac lists a 32K level 2 cache for the Plus and a 230 MB hard drive as standard, which disagrees with Apple on the cache.[10] It shares the Duo Dock II's top cover, base and subassembly and has its own logic board, 661-0975.[3]
Specifications
[edit | edit source]| Item | Duo Dock | Duo Dock II and Duo Dock Plus |
|---|---|---|
| Docking connector | Internal 152-pin processor-direct slot connector to the PowerBook; 32-bit expansion bus | |
| Floppy drive | Internal 1.4 MB drive, SWIM II MFM/GCR controller | |
| Hard drive bay | One 3.5 in, 1 in high SCSI drive on an internal 50-pin connector | |
| SCSI | HDI-30 port, 1.5 MB/s, built-in terminator; an HDI-30 SCSI system cable is needed for external devices | |
| Expansion | Two NuBus slots: two 15 W cards, or one 25 W and one 5 W | |
| Other ports | Two RS-422 serial (mini DIN-8), ADB (200 mA for all devices), mono sound in and out, DB-15 video, telephone pass-through for the Duo's internal modem | |
| Ethernet | None | Built in |
| Power supply | Universal AC, 85–270 V, 47–63 Hz, 75 W continuous, 85 W surge | Universal AC, 90–270 V, 47–63 Hz, 75 W continuous, 85 W surge |
| Dimensions (H × W × D) | 121 × 311 × 413 mm | 158 × 323.8 × 415.6 mm |
| Weight, no hard drive | 13.1 lb (5.95 kg); frame carries 60 lb | 15 lb; frame carries 85 lb |
| Operating temperature | 10–40 °C | 10–35 °C |
The power supply charges the Duo's battery while it is docked.[1] The docking motor runs at 5 rpm and gives 16 to 30 lb of pull-in force. A key lock at the front left holds the Duo in the dock; Apple made 125 key combinations, with no master key, and a hook on the back of the monitor stand takes a Kensington cable.[1]
Apple's own figures differ between documents. Apple Facts for October 1994 gives both docks as 5.1 × 12.5 × 16.3 in and the Duo Dock II as 13.5 lb, and says the Duo Dock carries displays up to 50 lb and the Duo Dock II up to 85 lb; the Service Source gives the heights above, 15 lb for the Duo Dock II and 60 lb for the original frame.[9][1] The Duo Dock Service Source limits ADB devices to 200 mA in total, while the PowerBook Duo 2300c Service Source allows 500 mA through a Duo Dock and 100 mA through a MiniDock or Floppy Adapter.[1][11]
Using the dock
[edit | edit source]The Duo Dock uses the hard drive inside the Duo, so the docked machine starts from the same files the Duo uses on the road.[6] The Duo's internal drive is SCSI ID 0 and a drive in the dock's bay is ID 1, so external devices take IDs 2 to 6. Terminate only the last external device.[12] The display stays closed while the Duo is inside the dock.[2] The Duo Dock II supports most Apple displays up to 21 in, including the Multiple Scan monitors, and has sync on green; the original supports Apple displays up to 16 in.[1]
A 2300c runs in a Duo Dock at an ambient temperature of 5 to 30 °C, lower than the 35 °C allowed when it is used alone or on a MiniDock.[11]
Construction
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The dock comes apart in layers: the top cover lifts off, the motorised release mechanism unscrews from the logic board, and the whole subassembly holding the logic board, NuBus adapter, floppy drive, hard drive bay, ejector and speaker lifts out of the base, which carries the power supply.[13] Each dock has a configuration ROM that tells the Duo which docking device it is in.[1] The full procedure is on Apple PowerBook Duo Dock General Maintenance.
| Part | Duo Dock | Duo Dock II | Duo Dock Plus |
|---|---|---|---|
| Logic board | 661-1657 | 661-1707 | 661-0975 |
| Top cover | 922-0519 | 815-0459 | |
| Subassembly | 922-0106 | 076-0466 | |
| Base | 815-0458 | 076-0465 | |
| Power supply | 661-1660 | ||
| Release mechanism | 922-0336 | ||
| NuBus adapter board | 922-0102 | ||
| Modem interface card | 922-0095 (US), 922-0094 (international) | ||
Known faults
[edit | edit source]The best-known failure is the "tick of death": the dock ticks when plugged in and will not power up, insert or eject. Low End Mac traces it to a failing 100 µF electrolytic capacitor at C28, or C24 on some power supply boards.[14] Apple's symptom chart for a dock that ticks with no raster has the reader measure 5 V ±0.5 V on pin 5 (yellow) and 20 V ±0.5 V on pin 7 (blue) of the power supply cable, and replace the supply if either is out.[15] A Duo trapped in an unpowered dock comes out through the square hole on the side of the dock: push the dock key or a small screwdriver into it.[15][16] Diagnosis is on Apple PowerBook Duo Dock Troubleshooting and the recap on Apple PowerBook Duo Dock Capacitor Replacement Guide.
Documentation
[edit | edit source]- PowerBook Duo Dock Service Source: Apple's 121-page Service Source for all three docks, January 1996.
- PowerBook Duo 200 Series Service Source: the Duo computers and the Duo Floppy Adapter.
Gallery
[edit | edit source]-
Front of a Duo Dock at the Computer History Museum (Marcin Wichary, CC BY 2.0) -
Apple's exploded view
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Related pages
[edit | edit source]- Apple PowerBook Duo Dock General Maintenance
- Apple PowerBook Duo Dock Troubleshooting
- Apple PowerBook Duo Dock Capacitor Replacement Guide
- Apple PowerBook Duo MiniDock
- PowerBook Duo General Maintenance
- PowerBook Duo Troubleshooting
References
[edit | edit source]- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 Apple Computer, PowerBook Duo Dock Service Source (Duo Dock, Duo Dock II, Duo Dock Plus), January 1996, Specifications chapter, PDF pp. 14–28. Hosted as File:PowerBook Duo Dock Service Source.pdf; described on PowerBook Duo Dock Service Source. Processor, memory, storage, ports, power supply, dimensions, environmental limits, docking motor and lock.
- ↑ 2.0 2.1 2.2 2.3 Wikipedia, "PowerBook Duo", section "Docking stations", https://en.wikipedia.org/wiki/PowerBook_Duo (read 4 October 2026). Introduction dates of 19 October 1992 (Duo Dock, model M7779), 16 May 1994 (Duo Dock II) and 15 May 1995 (Duo Dock Plus); M7780 for the MiniDock and M7781 for the Floppy Adapter.
- ↑ 3.0 3.1 3.2 3.3 Apple Computer, PowerBook Duo Dock Service Source, Exploded View, PDF p. 121. Service part numbers for each version.
- ↑ 4.0 4.1 4.2 4.3 Apple Computer, PowerBook Duo Dock Service Source, Basics chapter, "Duo Dock Configurations", PDF pp. 9–10.
- ↑ EveryMac.com, "Apple PowerBook Duo Dock Specs", https://everymac.com/systems/apple/powerbook_duo/specs/mac_powerbook_duodock.html (read 4 October 2026). Order numbers M4179LL/A and M2631LL/A, model M7779, introduction 19 October 1992.
- ↑ 6.0 6.1 Apple Computer, Apple Facts, February 1993, "Macintosh Duo Dock at a glance", PDF pp. 55–56, https://vintageapple.org/applefacts/pdf/Apple_Facts_9302_2.93_February_1993.pdf (retrieved 2026-10-04). Accessories, display weight, dimensions 4.8 × 12.5 × 16.3 in, weight 13.1 lb.
- ↑ Nicholas C. De Mello, FAQ about Macintosh Duos, revision of 9 July 1994, part 2, "Full-Docks", items 11 and 12. Contemporary user FAQ, distributed through the comp.sys.mac.portables newsgroup and the University of Michigan Mac archive. Part 2 of the May 1994 revision, as posted to comp.sys.mac.portables: Google Groups.
- ↑ 8.0 8.1 Apple Computer, PowerBook Duo Dock Service Source, Upgrades chapter, PDF pp. 96–119. VRAM SIMM (J9, 100 ns or faster), math coprocessor, modem interface card (J10, Japanese jumper on J3), hard drive (jumper A0 for SCSI ID 1, terminator off J8), NuBus cards, Duo Dock II upgrade.
- ↑ 9.0 9.1 Apple Computer, Apple Facts, October 1994, "PowerBook Duo Docking Products", PDF p. 90, https://vintageapple.org/applefacts/pdf/Apple_Facts_9410_10.94_October_1994.pdf (retrieved 2026-10-04). Duo Dock and Duo Dock II specifications, display weights, the 68030-only benefit of the FPU and cache, MiniDock specifications.
- ↑ EveryMac.com, "Apple PowerBook Duo Dock Plus Specs", https://everymac.com/systems/apple/powerbook_duo/specs/mac_powerbook_duodock_plus.html (read 4 October 2026). Order number M4219LL/A; introduction 15 May 1995; lists a 32K L2 cache and a standard 230 MB hard drive.
- ↑ 11.0 11.1 Apple Computer, PowerBook Duo 2300c Service Source, Specifications, PDF pp. 21 and 23. Hosted as File:PowerBook Duo 2300c Service Source.pdf. ADB current through each dock; operating temperature 5–30 °C in a Duo Dock.
- ↑ Apple Computer, PowerBook Duo Dock Service Source, Basics chapter, "SCSI Devices", PDF pp. 11–12.
- ↑ Apple Computer, PowerBook Duo Dock Service Source, Take Apart chapter, PDF pp. 56–94. Cover, release mechanism (motor cable J18), subassembly (power cable J11), logic board (J8, J11, J13, J14, J15, J17), NuBus adapter (J12), floppy drive, ejector, speaker, power supply, lock plug, base.
- ↑ Dan Knight, "The Duo Dock Tick of Death", Low End Mac, 2 September 2016, https://lowendmac.com/2016/the-duo-dock-tick-of-death/ (read 4 October 2026), adapted from Sean Cleary's Duo Dock page. Symptoms, opening the dock, removing the power supply, drilling out four rivets, capacitor at C28 or C24, 100 µF replacement.
- ↑ 15.0 15.1 Apple Computer, PowerBook Duo Dock Service Source, Troubleshooting chapter, PDF pp. 30–54. Symptom charts for startup, power, video, floppy drive, hard drive, peripherals, internal modem and miscellaneous faults; hard drives that do not spin up (Info Alley, June 1995).
- ↑ 68kMLA forum thread "DuoDock eats Duo 270c", October 2011 to February 2012, https://68kmla.org/bb/threads/duodock-eats-duo-270c.24125/ (read 4 October 2026). Dead power supply leaves the Duo stuck; Apple's manual eject hole frees it.