SDN (SDN Project)

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(Created page with "{{FormatInfo |formattype=electronic |subcat=Archiving |extensions={{ext|sdn}}, {{ext|sda}} |released=1989 }} An '''.SDN file''' is a compressed archive file associated with th...")
 
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An '''.SDN file''' is a compressed archive file associated with the ''SDN Project'' organization, and the ''SDNet/Works!'' software distribution network. ''SDN'' stands for ''Shareware Distribution Network''. SDN files are cryptographically authenticated.
 
An '''.SDN file''' is a compressed archive file associated with the ''SDN Project'' organization, and the ''SDNet/Works!'' software distribution network. ''SDN'' stands for ''Shareware Distribution Network''. SDN files are cryptographically authenticated.
  
An SDN file might be accompanied by an .SDA "abstract" file, which is just a text file describing the software in the SDN file.
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An SDN file might be accompanied by an .SDA "abstract" file, which is apparently just a text file describing the software in the SDN file.
  
 
== Discussion ==
 
== Discussion ==
There are at least two, and possibly three, different SDN formats.
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There are at least two or three different SDN formats.
  
 
The documentation for the ''SDNV'' utility says:
 
The documentation for the ''SDNV'' utility says:
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More research is needed, but it seems possible that the plan to switch to SDNV format was abandoned.
 
More research is needed, but it seems possible that the plan to switch to SDNV format was abandoned.
  
In 1993, it was announced<ref>[http://www.textfiles.com/fidonet-on-the-internet/939495/fido1004.txt fido1004.txt] - "SDN Changing Compression and Security"</ref> that SDN files would switch to a format based on [[ARJ]]. More research is needed here, as well.
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In 1993, it was announced<ref>[http://www.textfiles.com/fidonet-on-the-internet/939495/fido1004.txt fido1004.txt] - "SDN Changing Compression and Security"</ref> that SDN files would switch to a format based on [[ARJ]].
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 +
ARJ v2.41 (early 1993) introduced "SDN support". We've seen some ARJ files that use the SDN "security envelope" feature, but they have a .ARJ file extension, not .SDN. It's unclear if the .SDN file extension was ever routinely used for the SDN-ARJ format, though the ARJ documentation suggests that it was.
  
 
== Software ==
 
== Software ==
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* {{CdTextfiles|20mnn/APPLICAT/DRAFT.SDN|DRAFT.SDN}}
 
* {{CdTextfiles|20mnn/APPLICAT/DRAFT.SDN|DRAFT.SDN}}
 
* [https://archive.org/details/SDN1__793 SDN1 Plus] (CD-ROM)
 
* [https://archive.org/details/SDN1__793 SDN1 Plus] (CD-ROM)
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ARJ format:
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* {{CdTextfilesURL|goldmedal/}} → .../*.ARJ
  
 
== References ==
 
== References ==

Revision as of 20:24, 15 August 2020

File Format
Name SDN (SDN Project)
Ontology
Extension(s) .sdn, .sda
Released 1989

An .SDN file is a compressed archive file associated with the SDN Project organization, and the SDNet/Works! software distribution network. SDN stands for Shareware Distribution Network. SDN files are cryptographically authenticated.

An SDN file might be accompanied by an .SDA "abstract" file, which is apparently just a text file describing the software in the SDN file.

Contents

Discussion

There are at least two or three different SDN formats.

The documentation for the SDNV utility says:

SDN FILES BEFORE JUNE 15TH 1990.........................................
Files with  a .SDN extension  that were  packaged before June  15th 1990
were compressed using NoGate Consulting's PAK v2.10 utility. [...]

SDN FILES AFTER JUNE 15TH 1990..........................................
All files and programs, released  for distribution on SDNet/Works! after
June 15th  1990 will be  secured and  compressed in SDNV  format.  Other
archivers will not be able to read  or uncompress these .SDN files.  You
must use a the  SDNV utility SDNV.EXE. [...]

The older format is a PAK file with a special extended record. PAK itself is a variant of ARC.

More research is needed, but it seems possible that the plan to switch to SDNV format was abandoned.

In 1993, it was announced[1] that SDN files would switch to a format based on ARJ.

ARJ v2.41 (early 1993) introduced "SDN support". We've seen some ARJ files that use the SDN "security envelope" feature, but they have a .ARJ file extension, not .SDN. It's unclear if the .SDN file extension was ever routinely used for the SDN-ARJ format, though the ARJ documentation suggests that it was.

Software

PAK format:

SDNV format:

ARJ format:

Sample files

PAK format:

ARJ format:

References

  1. fido1004.txt - "SDN Changing Compression and Security"
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