Rick, (01)
The TR instruction merely translates bytes from one encoding
to another. It is actually rather trivial to implement. (02)
> Would you happen to have a pointer to a technical specification
> of the TR instruction ? You've mentioned this a few times and it
> seems quite relevant to the ontolog-forum. (03)
I mentioned it only because I wanted to emphasize that it was
stupid of IBM to use EBCDIC just because they wanted to avoid
the overhead of translating punched cards from the input
encoding to ASCII. (04)
For the record, the TR instruction requires two addresses
plus a length. (05)
To translate one 80-character card from EBCDIC to ASCII,
the first address would point to the address of the data
from the card, and the second address would point to a
256-byte table with the ASCII code for each EBCDIC code.
The TR instruction replaces each byte of the card data
with the selected byte from the table. (06)
If you need a reference, see page 7-149 of the IBM Z-series
principles of operation: (07)
http://lars.nocrew.org/computers/processors/zArchitecture/dz9zr001.pdf (08)
John (09)
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