20 Sep
2013
20 Sep
'13
12:51 p.m.
On 09/20/2013 11:40 AM, Dave wrote:
Many computers read them that way as well, but some
readers move the
card along the other axis, and so read a row of holes at a time....
I suppose one could make the argument that cards read in row-binary
could be read faster than if read in column-binary, but all of the very
high-speed card readers that I've ever seen (e.g. CDC 405), read card in
column-binary fashion; i.e. 12 holes at a time, rather than 80.
I suspect that may have been to accommodate "short" cards (40 column)
more easily. The 405 had gizmos that allowed for short cards.
The 415 punch, on the other hand, punched in row-binary fashion (i.e. 80
columns at a time).
A lot of unit-record gear operated in row-binary fashion also.
--Chuck