Blank Paper Tape Question (P.S.)

From: Ben Franchuk <bfranchuk_at_jetnet.ab.ca>
Date: Sat Mar 9 11:59:04 2002

Lawrence LeMay wrote:
>
> >
> > A low speed punch 10 cps vers a high speed punch
> > 50 cps could be a important cost factor. Now if you
> > had black paper tape one could zap out the holes
> > with a laser giving you a very high speed punch.
> > Since the punching speed does limit paper
> > tape to a practical limit of about 8kb was there
> > any really large paper tape programs? 4K focal on
> > a TTY was as long a program that I ever loaded from paper
> > tape ... 20 minutes.
> >
>
> Well, a good optical reader can read 400 characters per second. Correct me
> if i'm wrong, but that seems like 4096 bytes takes 10.24 seconds to read
> in. Assuming its not a 30 year old tape that vaporizes at that speed ;)
>
> -Lawrence LeMay

The TTY is the LOW speed punch/reader ... 10 CPS.
The high speed reader is 300 CPS for the PDP-8.
The problem with paper tape
on the PDP-8 at least is that you had to read a character at a
time. Read char... process ... read. This meant the paper tape
had to stop the tape on every character. Reading the tape is
not the problem ... stopping was.

-- 
Ben Franchuk - Dawn * 12/24 bit cpu *
www.jetnet.ab.ca/users/bfranchuk/index.html
Received on Sat Mar 09 2002 - 11:59:04 GMT

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