Module ram 

A read-only view of a paused calculator’s user memory: the HOME directory tree, the current directory, the data stack and the flags, read straight from RAM through the ROM’s own system pointers. Nothing is written and the calculator does not change mode, so a host can show it at any time; the values are those the ROM left when it last went idle (in its outer loop, the stack showing), which is where a paused machine normally sits.

Locations per model (48SX, 48GX, 49G) and the layouts: wiki: hardware/hp48-system-ram. The 38G, 39G and 40G keep aplets, not a HOME tree, and the 42S has no RPL user memory (its RAM holds HP-41-style programs and registers; wiki: hardware/hp42s); neither is covered.

Structs

Flags

The flags as 64-flag words, flag 1 (or -1) in bit 0 of the first.

Layout

Where a model’s ROM keeps its system pointers and flags in RAM (wiki: hardware/hp48-system-ram). Each *_ptr field is the address of a 5-nibble pointer.

UserMemory

User memory of a paused machine, read through layout.

Variable

A variable of a directory as the calculator lists it (VARS order, BYTES size and checksum).

Functions

change_counter

See UserMemory::change_counter.

crc

The calculator’s CRC over nibbles (wiki: hardware/crc; BYTES zeroes the CRC register and reads the object).

current_path

The current directory of machine, e.g. ["HOME", "A"].

flags

The flags of machine.

memory_tree

HOME’s variables of machine, newest first, with sub-directories.

stack_objects

The data stack of machine, level 1 first.