HP 15C Manuals

HP-15C HP-15C Quick Reference  A. Thimet Memory & Display Memory Approx. 462 bytes of memory corresponding to 66 registers, 7 bytes each, 4-level stack, Last-X, index register I. Nonvolatile memory, mostly merged program commands (1 byte per instruction) Pr Error Displayed when the contents of the nonvolatile (continuous memory) has been lost Number separator Turn off, press & hold ON, press ".", release ON, release "." This toggles between using a dot or comma for the decimal separator. Global reset Turn off, press & hold ON, press "-", release ON, release "-" This clears all permanent memory! MEM Displays memory assignment in the form "RR UU pp – n" with: RR: Number of highest storage register. At least 1 which means that R0, R1 and the index register I are always present. Register 0-19 correspond to 0-9 & .0-.9 and can be accessed directly by STO/RCL. Higher registers can be reached thru indirect addressing only. UU: Number of uncommitted registers. Use DIM to commit them to storage registers. Uncommitted registers are automatically converted to program space when needed. pp: Number of registers containing program instructions. One register consists of 7 bytes and can hold 7 program steps (except for a few instructions that occupy two bytes). n: Number of bytes left before next uncommitted register is converted to program space. In total there are 66 registers corresponding to 462 bytes. The initial setup is "19 46 0-0": 20 storage registers (0-19), 46 uncommitted registers, corresponding to approx. 322 program steps. DIM (i) Use this command to select the number of registers committed to storage. The argument must be passed in X. It specifies the highest storage register number. Registers containing program instructions cannot be converted to storage registers! X must be at least 1 so there will always be R0 and R1 available. The maximum is 65 FIX 0-9 Select fix-point format SCI 0-9 Select scientific format with exponent ENG 0-9 Select engineering format with exponent always being a multiple of 3 1