OakPDT Drawing

File Format
Name	OakPDT Drawing
Ontology	Electronic File Formats 3D and CAD/CAM Models OakPDT Drawing

Overview

OakPDT is a 2D parametric CAD system for RISC OS. On RISC OS systems, files in this format typically have a filetype of CAD ("PDT Dwg").

Format details

File Header
0	Byte	Major version number of the file format (always 1)
1	Byte	Minor version number of the format 2 corresponds to OakPDT v2.50 (17 November 1990)
2	Null-terminated string	The_Design_System or Oak_P_D_T_Drawing
20	Integer	Number of symbols (s)
24	Array	s symbol table entries
	Integer	Size of drawing definition (v)
	Array	v bytes
	Byte	Paper size
	Struct	Window definition
	Struct	Grid information
	Struct	Text information
	Struct	Dimension information
	Struct	Line style information
	Integer	Number of scalars (n)
	Array	n scalar table entries
	Struct	Error information
	Struct	Layer information
	Double	Dimension scale (only in v1.1 or later)
	Integer	Number of functions (n) (only in v1.2 or later)
	Array	n function table entries (only in v1.2 or later)
Symbol table entry
0	Byte
1	Byte
2	Byte
3	Byte
4	Integer
8	Integer
Window definition
0	Double
8	Double
16	Double
24	Double
Grid information
0	Double
8	Double
16	Double
24	Double
32	Integer
36	Integer
Text information
0	Double
8	Double
16	Double
24	Integer
Dimension information
0	Double
8	Double
16	Double
24	Double
32	Integer
36	Integer
40	Integer
44	Integer
Line style information
0	Integer
4	Integer
8	Integer
12	Integer
Scalar table entry
0	Integer
4	Null-terminated string
Error information
0	Integer
4	Null-terminated string
Layer information (v1.0 and v1.1)
0	Array	16 bytes
16	Array	16 bytes
32	Byte
33	Array	10 bytes
Layer information (v1.2)
0	Array	64 bytes
64	Array	64 bytes
128	Byte
129	Byte
130	Byte
131	Array	10 bytes
Function table entry
0	Null-terminated string
	Integer
	Integer