On Mon, 8 May 2000 07:51:17 -0800 Alan Kay <Alan.Kay at disney.com> wrote:
>They had 12 rows. The top two were called A and B, and were the only ones
>that could use combinations of holes. The bottom 10 could only have one
>hole per column ...

Well, that's if you were using a normal keypunch. IBM systems could punch object code onto cards one byte per column. This made for a fair number of holes. The Add Packed instruction (he says, slyly referring to his System/370 Reference Summary) was encoded as 12-11-0-2-8-9. Take a stack of those puppies and run them through the reproducing punch (no tiny machine, that) and the noise was atrocious.

Cheers,
Bob