20 Sep
2013
20 Sep
'13
5:26 p.m.
On 09/20/2013 04:06 PM, Chuck Guzis wrote:
Yup, the card reader on the 704 read cards starting
with the nine's row,
storing right and left sides into 26-bit words. Now you know why
FORTRAN reserved the last 8 columns for a sequence number--the 704
couldn't read them! The 1402 reader, read column-wise and I believe
all subsequent IBM readers did also.
(typo) Make that 36 bits!
Supposedly, the 5 column limit on FORTRAN statement numbers was derived
from the 15-bit width of the 704 index registers. I
don't know if that
story is apocryphal or not.
--Chuck