Editing Apple IIc (section)

===Improving the IIe===
The Apple IIc is an Apple IIe in a smaller case, more portable and easier to use but also less expandable. The IIc uses the CMOS-based [[WDC 65C02|65C02]] microprocessor which added 27 new instructions to the [[MOS Technology 6502|6502]], but is incompatible with programs that use [[illegal opcode]]s of the 6502. (Apple stated that the Apple IIc was compatible with 90–95% of the 10,000 software packages available for the Apple II.){{r|miller198407}}{{r|markoff198405}} The new ROM firmware allows [[Applesoft BASIC]] to recognize lowercase characters and work better with an 80-column display, and fixes several bugs from the IIe ROM. In terms of video, the text display adds 32 unique character symbols called "[[MouseText]]" which, when placed side by side, can display simple icons, windows and menus to create a [[graphical user interface]] completely out of text, similar in concept to IBM [[code page 437]] or [[PETSCII]]'s [[box-drawing character]]s. A year later, the Apple IIe would benefit from these improvements in the form of a four-chip upgrade called the [[Apple IIe#Enhanced IIe|Enhanced IIe]].