Teleprint 390

[Jim Beacon]

----- Original Message ----- 
From: "Paul Koning" <pkoning at equallogic.com>
To: <cctalk at classiccmp.org>
Sent: Wednesday, July 13, 2005 8:30 PM
Subject: Re: Teleprint 390


> >>>>> "Jim" == Jim Beacon <jim at g1jbg.co.uk> writes:
> 
>  Jim> My 11/45 has a seperate "Paper Tape Advance" output on the
>  Jim> console serial interface, whic is set by writing to a register -
>  Jim> I assume that the Teleprint 390 / ASR33 has either a solenoid
>  Jim> drive or a clutch that allows the tape to advance one character
>  Jim> at a time, under processor control.
> 
> Bit 0 in the receive control register, right?  That's supposed to be
> the papertape reader "reader run" signal.  It isn't used as a one
> character at a time thing; it is read/write and if set remains set
> until explicitly cleared.
> 
> The idea is that the system would accept interactive input by leaving
> this bit clear, but then when you told it to read a papertape it would
> set the bit.  That starts the tape.  The program would then see
> characters streaming in.  At some point (perhaps when it sees a string
> of nulls, or when it knows the tape is finished by some internal
> coding) it would clear reader run again.
> 
> I don't know if this actually was used much.  The ASR33s I remember
> rarely if ever had this hooked up; the reader run control was done by
> flipping the papertape reader switch on the machine.
> 
> I tried to find some code for it, but RSTS dropped the code in V9.6
> and that's the oldest I have...
> 
>     paul
> 

Paul,

thanks for clearing that up - I guess I mis-read the manual.

Jim