Dr. Halo PIC - Revision history

Sembiance: /* Sample files */

2023-12-28T15:42:01Z

‎Sample files

Jsummers: /* Format details */

2022-12-02T16:59:58Z

‎Format details

Sembiance: /* Software */

2022-11-19T02:58:54Z

‎Software

Jsummers at 18:37, 5 November 2022

2022-11-05T18:37:51Z

Jsummers at 14:27, 30 October 2022

2022-10-30T14:27:49Z

Jsummers: Split off from Dr. Halo

2022-10-29T12:38:34Z

Split off from Dr. Halo

New page

{{FormatInfo
|formattype=electronic
|subcat=Graphics
|extensions={{ext|pic}}
|released=1984
}}
'''Dr. Halo''' (including '''Dr. Halo Plus''' and '''Dr. Genius''') is a line of raster image editing software for DOS, developed by Media Cybernetics.

Its main native file format is '''.PIC'''. Sometimes, a PIC file has a companion '''.PAL''' file. This article is about PIC format, and the software in general. There are separate articles for some formats:
* [[Dr. Halo CUT]]
* [[Dr. Halo PAL]]

== Identification ==
PIC files start with ASCII "{{magic|AH}}", and the byte at offset 6 is <code>0x02</code>.

== Software ==
* Dr. Halo
** [https://winworldpc.com/product/dr-halo/ii Dr Halo II] (at WinWorld) - Includes v2.03, and a manual
** [https://archive.org/details/Dr.HaloIII3.0KyeOEM Dr. Halo III (v3.00/1988-02-02)]
** [https://winworldpc.com/product/dr-halo/iii Dr. Halo III] (at WinWorld) - Includes Dr. Halo III (v3.00/1989-02-06) & Dr. Genius (v3.00)
** [https://archive.org/details/Dr.HaloPlus3.00QTronixOEMGerman Dr. Halo Plus (v3.00-German)]
** [https://archive.org/details/Dr.Genius3.00KyeOEM Dr. Genius (v3.00)]
** [http://old-dos.ru/index.php?page=files&mode=files&do=show&id=6195 Various versions at old-dos.ru] - Includes Dr. Halo III (v3.01) and Dr. Halo Plus (v3.00).
** Possibly relevant: {{CdTextfiles|rbbsv3n1/dull/drhalo.unp|drhalo.unp}}

== Sample files ==
* {{CdTextfiles|librisbritannia/GRAPHICS/CLIPDRHA/1169.ZIP|1169.ZIP}}
* {{CdTextfilesURL|bthevhell/200/150/}} → screen*.pic (NSFW)

== Links ==
* [[Wikipedia: Dr. Halo]]
* [https://archive.org/details/DrHALOUsersGuideVersion1231984 Dr. Halo User's Guide (v1.23)]

[[Category:Multi-file formats]]

@@ Line 56: / Line 56: @@
 |8 || 2 || Unknown
 |-
-|10 || 2 || Graphics mode. This field is not always present.
+|10 || 2
 |}

← Older revision		Revision as of 18:37, 5 November 2022
Line 17:		Line 17:

	Some editions of Dr. Halo support several dozen video cards, each with a handful of graphics modes, so supporting the entire format would be quite difficult. But it is realistic to support files that use the standard CGA/EGA/VGA modes.		Some editions of Dr. Halo support several dozen video cards, each with a handful of graphics modes, so supporting the entire format would be quite difficult. But it is realistic to support files that use the standard CGA/EGA/VGA modes.
		+
		+	== Format details ==
		+	''[Some of this information is based on reverse engineering, and may be incorrect. Written for the fileformats.archiveteam.org wiki.]''
		+
		+	A PIC file consists of a header segment, followed by the compressed image data. Byte order is little-endian.
		+
		+	=== Header structure ===
		+
		+	{\| class="wikitable"
		+	! Offset !! Length !! Description
		+	\|-
		+	\|0 \|\| 2 \|\| "<code>AH</code>" signature
		+	\|-
		+	\|2 \|\| 2 \|\| Software version code?
		+	\|-
		+	\|4 \|\| 2 \|\| Unused?
		+	\|-
		+	\|6 \|\| 1 \|\| File type? Always 0x02.
		+	\|-
		+	\|7 \|\| 1
		+	\|Board ID? Known values:
		+
		+	{\| class="wikitable"
		+	! Value !! Description !! Implied header size
		+	\|-
		+	\|0x01 \|\| CGA \|\| 16
		+	\|-
		+	\|0x07 \|\| Hercules \|\| 10
		+	\|-
		+	\|0x15 \|\| EGA (4-plane modes) \|\| 12
		+	\|-
		+	\|0x3c \|\| VGA (1-plane modes) \|\| 16
		+	\|-
		+	\|0x47 \|\| VGA (4-plane modes) \|\| 12
		+	\|}
		+
		+	\|-
		+	\|8 \|\| 2 \|\| Unknown
		+	\|-
		+	\|10 \|\| 2 \|\| Graphics mode. This field is not always present.
		+	\|}
		+
		+	For 4-color CGA-like modes:
		+
		+	{\| class="wikitable"
		+	! Offset !! Length !! Description
		+	\|-
		+	\|12 \|\| 1
		+	\|0x10 bit: One of the palette selector bits.
		+
		+	Low 4 bits: Color of palette entry 0, from the standard 16-color PC/CGA palette.
		+	\|-
		+	\|13 \|\| 1 \|\| Unknown
		+	\|-
		+	\|14 \|\| 1 \|\| 0x01 bit: One of the palette selector bits.
		+	\|-
		+	\|15 \|\| 1 \|\| Unknown
		+	\|}
		+
		+	=== Compression scheme ===
		+	Compression is byte-oriented. The "next multiple of 512 bytes" instructions refer to the absolute file position.
		+
		+	To decompress, read a byte (N), follow the instructions below, repeat.
		+
		+	{\| class="wikitable"
		+	! Code byte (N) !! Instructions
		+	\|-
		+	\|N = 0 \|\| End of plane. If there are more planes, seek to the next multiple of 512 bytes.
		+	\|-
		+	\|1 ≤ N ≤ 127 \|\| Emit the next N bytes literally.
		+	\|-
		+	\|N = 128 \|\| End of block: Seek to the next multiple of 512 bytes.
		+	\|-
		+	\|N ≥ 129 \|\| Emit the next byte N−128 times.
		+	\|}

	== Identification ==		== Identification ==

@@ Line 148: / Line 148: @@
 * {{CdTextfiles|librisbritannia/GRAPHICS/CLIPDRHA/1169.ZIP|1169.ZIP}}
 * {{CdTextfilesURL|bthevhell/200/150/}} → screen*.pic (NSFW)
 == Links ==

@@ Line 105: / Line 105: @@
 ** [http://old-dos.ru/index.php?page=files&mode=files&do=show&id=6195 Various versions at old-dos.ru] - Includes Dr. Halo III (v3.01) and Dr. Halo Plus (v3.00).
 ** Possibly relevant: {{CdTextfiles|rbbsv3n1/dull/drhalo.unp|drhalo.unp}}
 == Sample files ==

@@ Line 10: / Line 10: @@
 * [[Dr. Halo CUT]]
 * [[Dr. Halo PAL]]
 == Identification ==