What's a "computer console" selectric called?

From: Don Maslin <donm_at_cts.com>
Date: Fri May 28 18:57:13 1999

On Fri, 28 May 1999, Arlen Michaels wrote:

> I don't think the Model 735 Selectric could even handle EBCDIC directly. I
> seem to recall the electrical interface was defined as tilt-and-rotate
> signal names. My Selectric terminal certainly didn't do any translation by
> itself from character-codes to solenoid signals, at least not from ASCII. I
> had to do translation myself before sending to the printer. One way would
> have been with hardware between the computer and the Selectric, eg- using an
> eprom to translate each ASCII code into the correct combination of Selectric
> tilt-and-rotate signals. My lazier way was to simply put a look-up table in
> my driver code, to intercept each ASCII character enroute to the printer and
> translate it into the appropriate pattern of solenoid signals first.

Well, considering the print speed capability of the Selectric mechanism,
your approach was unlikely to slow down the output.

> Imagine if you had to drive a dot-matrix print head with raw pin-driver
> signals instead of the printer hardware figuring it out for you : same kind
> of problem.

Seems to me that I recall just that approach in some of the early attempts
at printer graphics with CP/M.

                                                 - don

> Some vendors did indeed supply an interface that took ASCII from the
> computer and sent the necessary tilt-and-rotate signals out to the
> Selectric.
>
> Arlen
> --
> Arlen Michaels amichael_at_nortelnetworks.com
> Nortel Networks, Ottawa, Canada
>
>
Received on Fri May 28 1999 - 18:57:13 BST