SCRE2B - Revision history

Sembiance: /* Sample files */

2025-01-05T14:11:25Z

‎Sample files

Jsummers: /* Sample files */

2025-01-02T21:04:35Z

‎Sample files

Jsummers: Created page with "{{FormatInfo |formattype=electronic |subcat=Executable envelopes |released=1988 }} '''SCRE2B''' is a DOS utility that converts an EXE file to a [[DOS executable..."

2025-01-02T15:11:47Z

Created page with "{{FormatInfo |formattype=electronic |subcat=Executable envelopes |released=1988 }} '''SCRE2B''' is a DOS utility that converts an EXE file to a [[DOS executable..."

New page

{{FormatInfo
|formattype=electronic
|subcat=Executable envelopes
|released=1988
}}
'''SCRE2B''' is a DOS utility that converts an [[MS-DOS EXE|EXE]] file to a [[DOS executable (.com)|COM]] file that works the same.

It is a component of the [[SCRNCH]] v1.02 compression software by Graeme W. McRae. It is used by the included COMPRESS.BAT script.

== Discussion ==
SCRE2B is "high-tech", in that it does more than just strip off the EXE header.

The bulk of the generated COM file corresponds to the ''code image'' segment (refer to [[MS-DOS EXE#Special file positions]]) of the original EXE file. But the first 14 bytes are different. Following the copied code image segment is most of SCRE2B's boilerplate code.

If you use an [[Executable compression#Decompression software|executable decompression utility]] to decompress a SCRNCHed COM or EXE file, in some cases the result might be a COM file in SCRE2B format. Or, it might be such a file, but with an artificial EXE header added.

== Identification ==
The first 10 bytes of a generated file are {{magic|8c da 01 16 0c 01 ff 2e 0a 01}}.

(As mentioned previously, there are plausible workflows in which this format may be put into an EXE container. In such a case, the {{magic|8c da}}... byte sequence apears at the start of the ''code image'' segment, usually at offset 32 or 512.)

The string "{{magic|Program too big to fit in memory.}}" appears toward the end of the file.

== Software ==
* SCRE2B: Part of {{CdTextfiles|simtel/simtel9510/disk2/DISC2/COMPRESS/SCRNC102.ZIP|SCRNCH v1.02}}
* [{{SACFTPURL|pack|dese2b10.zip}} DeSCRE2B] - DOS utility to undo SCRE2B

== Sample files ==
* {{CdTextfiles|smsharew/MODEM/WHATPORT.ZIP|WHATPORT.ZIP}} → WHATPORT.COM (Valid but atypical file. SCRE2B has been applied twice.)

← Older revision		Revision as of 14:11, 5 January 2025
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	* {{CdTextfiles\|smsharew/MODEM/WHATPORT.ZIP\|WHATPORT.ZIP}} → WHATPORT.COM (Valid but atypical file. SCRE2B has been applied twice.)		* {{CdTextfiles\|smsharew/MODEM/WHATPORT.ZIP\|WHATPORT.ZIP}} → WHATPORT.COM (Valid but atypical file. SCRE2B has been applied twice.)
	* [https://archive.org/details/boston-2 Boston II] → DOS/SOUND/MODDMA/MODDMA.COM (hacked file)		* [https://archive.org/details/boston-2 Boston II] → DOS/SOUND/MODDMA/MODDMA.COM (hacked file)
		+	* {{DexvertSamples\|archive/scre2bPacked}}

← Older revision		Revision as of 21:04, 2 January 2025
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	== Sample files ==		== Sample files ==
	* {{CdTextfiles\|smsharew/MODEM/WHATPORT.ZIP\|WHATPORT.ZIP}} → WHATPORT.COM (Valid but atypical file. SCRE2B has been applied twice.)		* {{CdTextfiles\|smsharew/MODEM/WHATPORT.ZIP\|WHATPORT.ZIP}} → WHATPORT.COM (Valid but atypical file. SCRE2B has been applied twice.)
		+	* [https://archive.org/details/boston-2 Boston II] → DOS/SOUND/MODDMA/MODDMA.COM (hacked file)