20 Sep
2013
20 Sep
'13
2:27 p.m.
On 20/09/2013 20:51, Chuck Guzis wrote:
On 09/20/2013 11:40 AM, Dave wrote:
The only readers I have seen that read row binary were IBM but I said
"some" as I didn't know if they were the only readers that worked that
way. It seems obvious it should be faster that way so I have in the past
wondered if IBM had a patent on reading by the row...
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.
I don't see how that makes it easier. You still need an adjustable guide
of some kind. Did IBM equipment ever use short cards, or even the round
hole type...
The 415 punch, on the other hand, punched in
row-binary fashion (i.e.
80 columns at a time).
but no patent on punching....
A lot of unit-record gear operated in row-binary
fashion also.
--Chuck