4. Source files and file extensions

Common to all text source files are that they are expected to be in UTF-8, which is backwards compatible with the ASCII character set. For non-ASCII characters, UTF-8 uses multibyte sequences with the highest bit set (which is unused in ASCII). Thus, it is possible to type a character such as Σ or μ 1 which are not present in ASCII. See Alpha strings for available special characters.

Unfortunately the HP-41 character set uses some very special characters, known as the hangman characters that is not available in UTF-8. If you want to use such characters, you will need to resort to using numeric constants or hex escape sequences, as they cannot be typed.

Footnotes

1

When such character is used in a character or string literal, it will be translated to the corresponding HP-41 character, or LCD character depending on the context. Unicode characters can also be used in back quoted symbols.

4.1. File extensions

The following table lists file extensions used with the tools.

Table 4.1 File extensions

Extension	Purpose
.s	Assembler source
.o	Object file
.a	Library (collection of object files)
.lst	List file
.scm	Linker rules file
.moddesc	Module description (XML)
.modexport	Module exports (XML)
.mod	HP-41 module format (binary output), packed 10-bit word representation
.mod2	HP-41 module format (binary output), 16-bit words representation for NEWT
.elf	HP-41 ELF output (binary output)
.rom	Module page as raw data (16-bit words)
.raw	RPN binary images (raw bytes)
.rpn	RPN source program