To use, just transfer all five programs to your calculator and run ZCALC from in Doors CS. You may enter just about anything to be evaluated; for example: 4-(9*7) would return -59 For the most part, TI-OS syntax errors are avoided. However, there are some more useful commands, rather than such boring 'fixed' arithmetic operations. Each of these commands are provided by a plugin program. Included are ZRECALL, ZSETNUM, and ZGRAPH. Provided commands: Command invocation | Provided by | Notes SET [0-9],x ZSETNUM x may be any number or expression, sets a variable [x] ZRECALL x is a digit from 0-9, and the corresponding numbered variable is substituted for the expression (so if var 0 is pi and you enter "5[0]^2", it would become 5(pi)^2) GRAPH function ZGRAPH graphs function on the coordinate plane, then pauses ZOOM [IN,OT,ST,NT] ZGRAPH Zooms the graph screen in (IN), out (OT), to standard (ST), or to integers (NT)