> On May 16, 2024, at 11:22 AM, Martin Bishop via cctalk
> <cctalk@classiccmp.org> wrote:
>
> It looks as though Decitek remain in business
> http://www.decitek.com/index.html
>
> Scan of a series 700 reader manual on bitsavers
> http://www.bitsavers.org/pdf/decitek/
>
> On an optical reader, I would not recon the capstan running at power on as
> unusual - a pinch roller which engages for drive and a tape clamp engaging
> for stop motion are both common features. For simple single byte read
> operations, probably the paradigm used when the unit was built, it is not
> uncommon for the sprocket hole to stop feed and energise clamp.
There are two basic design schemes for optical tape readers: a sprocket wheel
that engages the tape and does the start-stop motion, typically with a stepper
motor; and a transport roller with pinch roller and brake, typically solenoid
driven. The DEC PC11 is an exaxmple of the former. The latter are more likely
to show up in high speed readers because the tape motion is continuous, so
easier on the tape as long as it doesn't need to stop.
I'm still amazed at the Electrologica X8 tape reader, rated at over 1000
characters per second, and able to stop and restart without skipping a byte.
paul
