Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!linus!decvax!ittvax!bunker!jrh
From: jrh@bunker.UUCP (Jeff Hagen)
Newsgroups: net.micro
Subject: hardware question
Message-ID: <502@bunker.UUCP>
Date: Mon, 20-Aug-84 14:38:55 EDT
Article-I.D.: bunker.502
Posted: Mon Aug 20 14:38:55 1984
Date-Received: Wed, 22-Aug-84 03:38:49 EDT
Lines: 26

xxxx

Here is a little hardware problem I came across:

I have and old TI thermal printer (PC100A) that works with their
58/59 calculators.  I thought it might be kind of neat to interface
it to my computer.  I have the description of the calculator/printer
interface (from the TI technical manual).

problem : The five unidirectional logic lines in the interface
          use a 0 volt to -10 volt logic.

question:  Is this TI logic some sort of standard?

           and more importantly,

           Is there an easy way to interface it to TTL ?

Someone suggested a high speed op amp, but isn't this overkill?
(the clock frequency is about 227khz ).

             
                               Thanks for listening
                        
                               Jeff Hagen
                               ittvax!bunker!jrh