Module cmdline 

The command line being edited and the state of the ROM’s editor (entry mode, alpha, shifts), read from RAM without pressing a key.

The ROM keeps the text reversed and NUL-terminated just below its temporary environments, with no length field; the cursor and the editor’s flags sit in system RAM. Locations per model were found by observation (wiki: hardware/command-line; the 28S: wiki: hardware/hp28s “Command line”).

Structs

CommandLine

The commandLine protocol answer.

Editor

The editor as the ROM left it.

EditorLayout

Where a model’s ROM keeps its editor in RAM (wiki: hardware/command-line). *_ptr fields hold 5-nibble pointers; the others are nibbles whose bits are listed with them.

Hp28

Where the 28S’s ROM (2BB, its only revision) keeps its command line (wiki: hardware/hp28s “Command line”). The text is kept as on the 48, reversed below a pointer, and zeroed when the line closes; the line closes when it empties, so an open line always has text.

Constants

MAX_CHARS

Most characters read (the 49G’s RAM could hold more, but no line the ROM edits is that long; more means the pointers are not the ROM’s).

Functions

command_line

The command line of machine: open or not, its text and cursor.

editor

The editor of machine (48SX, 48GX, 49G, 28S).

read

Read the editor through layout.

read_hp28

Read the 28S’s editor (Hp28). Its shift and α show on the annunciators, so left_shift and alpha stay false here, as do the fields it has no counterpart for.