# readseg

> **Tool `tools/dos/readseg.py`** (program, 16-bit DOS). Read typed values from a DOS (MZ) or 16-bit NE executable at Ghidra's seg:off addresses.

Run it with `./gameframe run readseg ARGS` or `python3 tools/dos/readseg.py`. [Source on GitHub](https://github.com/tanepiper/game-frame/blob/main/tools/dos/readseg.py).

## Its own help

This is the help text in the tool itself, as `./gameframe tool readseg` prints it.

```text
Read typed values from a DOS (MZ) or 16-bit NE executable at Ghidra's seg:off addresses.

Usage: readseg.py BINARY TYPE ADDRESS [ADDRESS ...] [--count N]

The 16-bit counterpart of tools/pe/readdata.py, for the DAT_1008_0004 globals in pseudocode and
for Pascal "typed constants" (initialised variables in the data segment). TYPE is:

  u8 i8 u16 i16 u32 i32     integers (Pascal byte, shortint, word, integer, longint)
  ptr                       a far pointer, offset word then segment word, printed seg:off
  real48                    Turbo Pascal's 6-byte Real (not IEEE: exponent byte first)
  f32 f64 f80               single, double, extended (x87 80-bit)
  pstr                      a Pascal string: a length byte, then the text (string[N])
  cstr                      a zero-terminated string
  hex                       16 * count raw bytes

ADDRESS is as Ghidra prints it: 1008:0004, DAT_1008_0004 or FUN_1000_0028 (NE selectors are
0x1000 + 8 * (segment - 1); MZ images are loaded at segment 0x1000). `--count N` reads N
consecutive values (a table). Values are as stored in the file, before the program runs:
relocated words (selectors, far pointers to segments) still hold the file's placeholder.
It does not read memory the program fills at run time (use dos_emu or DOSBox-X for that).
```

## Named by

Skills: [re-ghidra](/skills/re-ghidra).