[Simh] Card Readers on PDP-11's

[Paul Koning]

> On Feb 13, 2020, at 12:17 PM, Robert Thomas <rft at asthomas.com> wrote:
> 
> ...
> The Documation card reader was fairly reliable and didn't chew up as many cards as the IBM reader.

I can believe that.  The IBM card readers and punches I've seen (on a 360/44) had a pick mechanism that moves a metal block with a small step in it, sized to match the nominal thickness of the card.  This was supposed to catch the far edge of the card and *push* it into the throat of the feed mechanism.  If there was anything slightly wrong, it would accordeon-fold the card instead.

The Documation readers had vacuum operated pick mechanisms that acted on the leading edge of the card.

	paul