Input History Mode

Most AutoCAD keyboard junkies (including me) learned a long time ago that hitting the "up" arrow retrieved the last thing you typed. (Handy for correcting typos!) With the advent of dynamic input, though, that seemed to have disappeared. Enter the system variable INPUTHISTORYMODE. This is a slightly complicated variable, dealing with the recent coordinate input as well as recent command input. It can have any value between 0 and 15. The default is 15, so hitting the up arrow displays recent coordinates if you're in a command, and recent commands if you're not. Recent Input sections are also displayed in shortcut menus and the dynamic tooltip (if it's on). Values from 1-14 control various combinations of shortcut menu and command line displays; see the help file if you're curious. Setting INPUTHISTORYMODE to zero means that no recent input is displayed, and when you hit the up arrow, you get the last thing you typed. Personally, I set it back to 0 as soon as I realized this variable existed.