MessagePad refers to the line of newton OS based PDAs made by Apple Computer from 1993 to 1998. The first popular PDA, MessagePads were the covettes of the PDA world for a long time.

The models are:

  • Original (MessagePad Classic) - 20 mhz ARM 610 CPU. ~124kb usable storage. Side-siloed "triangle" stylus. 320x246 LCD at 85 DPI, 1-bit. 1 top-mounted PCMCIA Type II slot. 4xAAA power source. Mini-DIN-8 RS-422 Serial port. ASK IR. Final OS: 1.1 (1.3 with ROM Upgrade).
  • 100 - Same as classic, but with ROM Upgrade.
  • 110 - 20 mhz ARM 610 CPU. 500kb storage (~400kb user). Top-siloed "spring-bean" stylus. 320x240 LCD at 85 DPI, 1-bit. Side mounted PCMCIA Type II slot. 4xAA power source. Mini-DIN-8 RS-422 Serial port. ASK IR. Final OS: 1.3. Also made available was a transparent platic model, sold to developers.
  • 120 - Same as 110 with improved reset and PC Card release switches, 500kb/2mb model and socket ROMs for optional upgrade to Newton OS 2.0. Final OS: 1.3 (2.0 with ROM upgrade).
  • 130 - Same as 120 but with Backlit LCD and 2mb storage standard. Final OS: 2.0.
  • 2000 - 161mhz ARM CPU. 5mb storage, 1mb of "heap" (used for dynamic allocation, like RAM on standard computers). Side-Siloed chrome stylus. 640x480 backlit LCD at 100 DPI, 4-bit. 2 side mounted PCMCIA Type II card slots. 16-but Audio in/out. 4xAA Power source. ASK and IrDA IR, but not totally IrDA compatible, lacks some parts of the standard layers. Final OS: 2.1.
  • 2100 - Same as 2000 but with 8mb storage, 4mb of heap memory. 2000 units could be upgraded.

Thanks go to dakkar for some corrections to the 2000,2100.