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In 1984 the new kid on the block was Borland's Sidekick. A terminate and stay resident (TSR) program for MS-DOS, it would run in the background, and when it detected the two shift keys being pressed it would overlay the (then character) screen with a calculator, a notepad, a calendar, a dialer or an ASCII table.

In 2005 one of the shiny new cool features of Apple's Mac OS X is the Dashboard. This will overlay the (now bitmapped) screen with a calculator, sticky notes, a calendar, a phone book, the weather report, and hundreds of other widgets. How things have changed...

Interestingly, on my system the virtual memory size of my dashboard's seven processes is 48,644MB and the resident set size (the actual amount of physical memory occupied) is 27,364MB. The memory occupied by Sidekick 2.0 is 40,400 bytes, three orders of mgagnitude less than dashboard. Here are the details.

Sidekick

Before loading:

   655360 bytes total conventional memory
   655360 bytes available to MS-DOS
   588112 largest executable program size

After loading:

   655360 bytes total conventional memory
   655360 bytes available to MS-DOS
   547712 largest executable program size

Dashboard

USER       PID %CPU %MEM      VSZ    RSS  TT  STAT STARTED      TIME COMMAND
dds        207   0.0  3.0   111268   7892  ??  S     8:30AM   0:00.69 /System/Library/CoreServices/Dock.app/Contents/Resources/Dashb
dds        208   0.0  2.9   103144   7692  ??  S     8:30AM   0:01.57 /System/Library/CoreServices/Dock.app/Contents/Resources/Dashb
dds        209   0.0  2.4   100624   6208  ??  S     8:30AM   0:09.61 /System/Library/CoreServices/Dock.app/Contents/Resources/Dashb
dds        210   0.0  2.0    83412   5316  ??  S     8:30AM   0:00.43 /System/Library/CoreServices/Dock.app/Contents/Resources/Dashb
dds        211   0.0  2.5   101980   6436  ??  S     8:30AM   0:00.56 /System/Library/CoreServices/Dock.app/Contents/Resources/Dashb
dds        212   0.0  2.3   101856   5940  ??  S     8:31AM   0:00.52 /System/Library/CoreServices/Dock.app/Contents/Resources/Dashb
dds        214   0.0  3.3   111776   8712  ??  S     8:31AM   0:01.41 /System/Library/CoreServices/Dock.app/Contents/Resources/Dashb

The Difference

A crucial difference between the two systems is that Sidekick was a closed application with a fixed set of accessories, while anyone who can write an HTML page can also write a new Dashboard widget. Intriguingly Dashboard widgets also offer superb integration with the Unix shell and a dazzling graphics capability, so I'll probably be experimenting with them in the near future. I consider the Dashboard's programmable widgets to be an innovation on GUI development on par with Visual Basic. More details on widget development are available on Apple's site.

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