[delta-l] Exporting DELTA-format data from Intkey

Mike Dallwitz m.j.dallwitz at netspeed.com.au
Fri Jan 20 12:07:13 CET 2012


- From: Craig Robbins

> The way I understand the Intkey binary format is that its primary purpose
> is for diagnosis/keying. So, those data you mention that are lost are not
> stored because they are not essential in the context of identifying a
> specimen. Is that correct?

All the data can be valuable for identification (and for information 
retrieval). The reason for the development of the Intkey format was 
efficiency.

Intkey was first released in 1988 (or perhaps earlier - it's mentioned in 
the DELTA Newsletter of February 1988). The PCs in use at that time were 
slow, and memory and disk space were small. The earliest release notes 
that I have (December 1988) say 'The programs should run on any MS-DOS 
system with at least 512K of memory'. That would (I think) include 
computers without any hard disk - just two 360KB floppy disks.

To minimize memory use, and for quick access, the Intkey format uses 1 bit 
per characters state in the data matrix. To further speed up access for 
the most common operations, the data are arranged by characters, instead 
of by taxa as in the DELTA data.

Intkey format was never intended as a data interchange format, whereas 
DELTA was specifically designed for that purpose.

If the DELTA project had continued, we intended that a future version of 
Intkey would use the full data, probably in the internal format used by 
the DELTA Editor. Nevertheless, for efficiency it might have been 
necessary to also include indexing of the data, perhaps along the lines of 
the current Intkey.

-- 
Mike Dallwitz
Contact information: http://delta-intkey.com/contact/dallwitz.htm
DELTA home page: http://delta-intkey.com


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