Philippe,
Those aren't negative digits, per se. The usage in the manual is with an
overline (or macron) to indicate the flag bit. It does occur over a
zero, and in explanation in the text of floating point operations, it is
also shown over letters (X, M, E) representing digits of the exponent
and mantissa. See p. 27 (31 of the pdf) in that same manual, for an
extensive discussion with lots of examples in the text:
http://www.bitsavers.org/pdf/ibm/1620/A26-5706-3_IBM_1620_CPU_Model_1_Jul65.pdf
The Unicode representation of the text material printed on that page
would best be done with a combining macron, I think.
--Ken
On 9/26/2017 6:34 AM, Philippe Verdy via Unicode wrote:
But what is interesting is the use of negative digits (-1 to -9, with
the minus sign above the digit; I've not seen a case of minus 0, not
needed apparently by the described operations)
How do you encode these negative decimal digits in Unicode ? with a
macron diacritic ?
