The PowerBook Duo was an interesting and really quite revolutionary concept in mobile computing, that Apple sadly discontinued.

Cute and small

The Powerbook Duos were subnotebooks. They were small and light. They didn't have floppy or optical drives or the normal range of ports (just a serial port, except for the 2300 which had a SCSI port), after all how often are you going to use that connector for an external keyboard when you're on the move?

When you got home however, things changed, as they had a special connector that allowed you to connect to a "DuoDock". From the outside a DuoDock looked similar normal Macintosh desktop, In the front there was a door through which your Duo slid in. Once this done it gained the usual connection ports, an FPU in some cases, NuBus slots, more VRAM, more RAM, floppy drive (known in those days as a Superdrive, although that now refers to a DVD writer), more hard disk etc...

In chronological order, the Duos produced were the: 210, 230, 250, 270c, 280, 280c, 2300. The first one off these rolled of the assembly lines in October 1992, and the last one was discontinued in February 1996, leaving a gaping hole in Apple's product line.

Roll call

Brief stats for each model follow:

  • Duo 210:
    • Processor: 25 MHz 68030, optional FPU in dock
    • Screen: 640x400, 16 levels of grey, passive matrix
    • Introduced: October 1992 @ $2250
    • Discontinued: October 1993
  • Duo 230:
    • Processor: 33 MHz 68030, optional FPU in dock
    • Screen: 640x400, 16 levels of grey, passive matrix
    • Introduced: October 1992 @ $2610
    • Discontinued: July 1994
  • Duo 250:
    • Processor: 33 MHz 68030 with FPU
    • Screen: 640x400, 16 levels of grey, active matrix
    • Introduced: October 1993 @ $2500
    • Discontinued: May 1994
  • Duo 270c:
    • Processor: 33 MHz 68030, optional FPU in dock
    • Screen: 256 colors at 640x480 or 32768 colors at 640x400, active matrix
    • Introduced: October 1993 @ $3100
    • Discontinued: May 1994
  • Duo 280:
    • Processor: 33 MHz 68LC040
    • Screen: 640x400, 16 levels of grey, active matrix
    • Introduced: May 1994 @ $2600
    • Discontinued: November 1994
  • Duo 280c:
    • Processor: 33 MHz 68LC040
    • Screen: 256 colors at 640x480 or 32768 colors at 640x400, active matrix
    • Introduced: May 1994 @ $3750
    • Discontinued: January 1996
  • Duo 2300:
    • Processor: 100 MHz 603e
    • Screen: 256 colors at 640x480 or 32768 colors at 640x400, active matrix
    • Introduced: August 1995 @ $3700 or 4700, depending on configuration
    • Discontinued: February 1996
All of the Duos share a similar form factor, a compact 1.4" H x 10.9" W x 8.5" D. They were true lightweigths, weighing in between 4.2 and 4.8 pounds (the ones with color screens being the heavy ones). The casings were black plastic and used a trackball as their pointing device. Some found the keyboard to be a bit small for their taste, but that's the price to pay for a laptop that size.

Docks galore

As said before, these were what turned your PowerBook Duo into a normal machine when you got home. There were 3 PowerBook DuoDocks, in order of production: the original PowerBook Duodock, the DuoDock Plus and the DuoDock 2. The DuoDock Plus and DuoDock 2 were identical, apart from the Plus' FPU. They had more VRAM that the original DuoDock and had a AAUI Ethernet connector. They originally retailed for around $500. Also available was the MiniDock. It plugged in to the back of the PowerBook and gave you a full range of ports as well as a floppy drive but allowed you to use the PowerBooks screen and could run of the PowerBook's batteries. Obviously it didn't have any NuBus slots. Some third parties also made docks.

A nice idea, however maybe not necessary today. iBooks or the 12 inch Powerbook G4 are almost as small, but without any of the tradeoffs. The Duos did have the advantage that they were unlikely to burn your genitals (although this is only of concern to men).

Sources: http://www.lowendmac.com
http://www.apple-history.com
http://www.everymac.com/systems/apple/powerbook_duo/stats/mac_powerbook_duodock.html