[OT] paper on Retro ?

From: Gary Oliver <go_at_ao.com>
Date: Sun Oct 20 18:02:00 2002

Another bit of (perhaps true) trivia re IBM cards: I was told once by
a (Control Data) field engineer that the size of the original SSSD
8 inch floppy was chosen to be approximately a box of cards (he claimed
to be an amateur computer historian even way back in the late 70s.) The
original IBM floppy dimensions were:

  77 tracks * 26 sectors = 2002 sectors per disk = approx one box of cards.

Never mind the sectors were 128 bytes long instead of 80... The extra
was just extra, I guess.

I have no personal "knowledge" that this is true. I thought that the
original
usage for the diskettes was as an IPL storage to initialize the microcode
on some early 360 mainframes. But, again, I'm not too knowlegable about
IBM gear. Control Data, maybe, but IBM not at all.

I seem to recall seeing some (non IBM) key-to-disk machines that operated
like a keypunch but it produced one card image per sector on those 8 inch
floppies. Anyone know who made these? Was it IBM and if so, what was
the equipment designation?

Tony Duell wrote:

>>Can anyone remember how many IBM cards fit in a box? A card is nominally 8
>>thou thick, and a tray is about 16.5" long internally, so it must be
>>something of the order of 2000.
>>
>>
>
>I beleive it is eaxctly that...
>
>
>
>>Who remembers drawing a cross or a diagonal line on the top of the card
>>deck, so you had some chance of re-ordering the deck if someone dropped the
>>box?
>>
>>
>
>Who _doesn't_ :-). Actually the line was more use as a sanity check that
>the deck had not been shuffled. There wasn't normally enough resolution
>to completely sort a deck using it.
>
>
>
>>Who remembers using a folded card (16 thou) to check the points on their
>>engine (nominally 15 thou)? Folded in three to check the spark plug gap
>>(nominally 25 thou)??
>>
>>
>
>I remember (once) using a credit card to set the plug gap on a teacher's
>car at school (don't ask -- I had a somewhat odd reputation even back
>then...)
>
>-tony
>
>
Received on Sun Oct 20 2002 - 18:02:00 BST