Crimson Calculator 41cx

The Calc41Cx is a programmable, continuous memory RPN calculator with the following features:

Access to the stack and LASTx via STO and RCL commands.
200-2000 Lines of program memory.
Label addressing with strings
30 user and 26 system Flags.
Conditional and unconditional branching
Convenient insertion and deletion of program steps.
Indirect addressing via any register using the IND modifier.
ISG and DSE looping.
6 levels of subroutines.
Alphanumeric display, storage, and programming.