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On Thu, Aug 24, 2006 at 11:56:03PM +0200, Martin Schröder wrote:
> 2006/8/24, Dave Dodge <dododge@dododge.net>:
> >Some 1960s IBM mainframes such as the 360 have BCD instructions.  I
> 
> According to http://en.wikipedia.org/wiki/Binary-coded_decimal, IBM's
> BCD is 6-bit, while normal BCD is 4-bit.

If you look carefully, wikipedia says that's for the pre-360 systems.

The 360 has (at least) two BCD formats: "zoned decimal" which uses 8
bits per digit, and "packed decimal" which uses 4 bits per digit.
There are instructions for working with each format.  As I recall even
the "quick reference" guide for the 360 instruction set was
book-sized.

http://www.csc.fi/cschelp/sovellukset/stat/sas/sasdoc/sashtml/lrcon/z1266482.htm