Reading ancient paper digital media (was Re: Hamurabi Focal source)

Fred Cisin cisin at
Mon Apr 5 15:25:08 CDT 2010

> On 4 Apr 2010 at 1:29, CSquared wrote:
> >  I do remember the 084 was one more screaming fast card sorter; I
> > rather suspect that brush bounce etc. was just too much to cope with to
> > achieve reliable operation at that speed. I'm trying unsuccessfully to
> > remember just what the read rate was for the 084.  Anyone remember?

Change from brushes to photocells was essential to getting the speed up.

On Mon, 5 Apr 2010, Chuck Guzis wrote:
> One doesn't need a memory with the web.  From the Columbia university
> web site
> Type 84 	19?? 	2000 cpm
> "For some reason, IBM didn't produce a card reader that operated at
> 2000 cpm. The 084 was unique in that it used a vacuum-assist card-
> feed mechanism that did not require the use of a card-weight, as the
> cards were held against the throat and picker knives by suction. The
> 084 also used an optical method of detecting card punches instead of
> the wire brush used by earlier models. "
> I never got to use an 084, just an 082--there must have been a
> jillion of those in service.

I never used an 084, either.  Vacuum? photocell??   2000 CPM???  WOW!
Must have been 082s.  Were there any earlier minimal models without
counters?  ISTR some elation over upgrade.

Without refressh, wetware dynamic RAM decays.
Since there isn't adequate ECC,
the mind lets it pass with incorrect data!

Grumpy Ol' Fred     		cisin at

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