Apple II Technical Notes _____________________________________________________________________________ Developer Technical Support Apple IIGS #58: Keyboard Modifiers Register Anomaly Written by: Dave Lyons July 1989 This Technical Note discusses an anomaly with the keyboard modifiers register at location $C025 which prevents it from always properly reflecting the state of the Control and Shift keys. _____________________________________________________________________________ There are two cases where pressing the Control key turns on the Shift bit instead of the Control bit in the keyboard modifiers register: o An arrow key (or a Control key equivalent to an arrow key) is being held down and is repeating o The Space bar or Delete key is being held down and repeating with the Fast Space/Delete option selected in the Control Panel Since the Event Manager reads the modifiers byte, desktop applications may be affected by this anomaly. Further Reference _____________________________________________________________________________ o Apple IIGS Hardware Reference