The MacCharlie was a hardware add-on for the Apple Macintosh that was made by Dayna Communications. The name refers to an IBM PC advertising campaign of the time featuring Charlie Chaplin's "Little Tramp" character.
It allowed users to run DOS software for the IBM PC by clipping on a unit to the chassis of the 128K Macintosh, as well as a keyboard extender to provide the function keys and numeric keypad that were absent from Apple's original keyboard.
The clip-on unit sat to the side of the Mac and, like the contemporary Amiga Sidecar, contained essentially a complete IBM PC compatible with an 8088 processor, 256K RAM (expandable to 640k) and a single 5.25" floppy drive that stored 360K. A second floppy drive could be added.
While running DOS software, users could still access the Macintosh menu bar and desk accessories. MacCharlie used the Mac as a terminal, performing all DOS processing itself, and sending video data over a relatively slow serial link to the Mac for display. This slowness, coupled with the declining prices of real IBM PC compatibles, contributed to the short market life of the MacCharlie.