TheDraw COM File

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It is in the form of a [[DOS executable (.com)|DOS .COM]] file that, when executed, prints the graphics to the screen.
 
It is in the form of a [[DOS executable (.com)|DOS .COM]] file that, when executed, prints the graphics to the screen.
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== Format details ==
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There are three "types" of the format, distinguished by the byte at offset 6 having value 0, 1, or 2.
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Types 1 and 2 were introduced in version 4.00. TheDraw selects the type to use automatically. Type 1 seems to be rare, and is used only if the image is incompressible.
  
 
== Identification ==
 
== Identification ==
TheDraw COM files are observed to have ASCII text "{{magic|TheDraw COM file Screen Save}}", followed by byte value <code>0x1a</code>, at offset 9.
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Type 0 files start with bytes {{magic|eb 3d 90}}, and have <code>00</code> at offset 6.
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Type 1 files start with bytes {{magic|eb 18 90}}, and have <code>01</code> at offset 6.
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Type 2 files start with bytes {{magic|eb 3d 90}}, and have <code>02</code> at offset 6.
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Types 0 and 2 have the signature string "{{magic|TheDraw COM file Screen Save}}" at offset 9, followed by byte <code>0x1a</code>.
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Type 1 has the shorter string "{{magic|TheDraw COM file}}" at offset 9, followed by <code>0x1a</code>.
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See also [[P-Screen COM Screen]], which looks a lot like type 0, except for the different signature string.
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== Specifications ==
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* An overview of the decompression algorithm for type 2 is in the UNCRUNCH.PAS file included with TheDraw 4.x.
  
 
== Software ==
 
== Software ==

Revision as of 15:46, 15 January 2023

File Format
Name TheDraw COM File
Ontology
Extension(s) .com
Released 1989

TheDraw COM File is a format for ANSI Art-style character graphics, associated with the DOS software TheDraw. The format was introduced in TheDraw v3.20 (1989-04).

It is in the form of a DOS .COM file that, when executed, prints the graphics to the screen.

Contents

Format details

There are three "types" of the format, distinguished by the byte at offset 6 having value 0, 1, or 2.

Types 1 and 2 were introduced in version 4.00. TheDraw selects the type to use automatically. Type 1 seems to be rare, and is used only if the image is incompressible.

Identification

Type 0 files start with bytes eb 3d 90, and have 00 at offset 6.

Type 1 files start with bytes eb 18 90, and have 01 at offset 6.

Type 2 files start with bytes eb 3d 90, and have 02 at offset 6.

Types 0 and 2 have the signature string "TheDraw COM file Screen Save" at offset 9, followed by byte 0x1a.

Type 1 has the shorter string "TheDraw COM file" at offset 9, followed by 0x1a.

See also P-Screen COM Screen, which looks a lot like type 0, except for the different signature string.

Specifications

  • An overview of the decompression algorithm for type 2 is in the UNCRUNCH.PAS file included with TheDraw 4.x.

Software

Sample files

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