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From: tony@sdd.hp.com (Tony Parkhurst)
Newsgroups: comp.sys.amiga.misc,comp.sys.amiga.hardware,comp.sys.amiga.programmer
Subject: Re: HP ThinkJet and DEC LA-50
Message-ID: <1991Jan15.150740@sdd.hp.com>
Date: 15 Jan 91 23:07:40 GMT
References: <22504@frog.UUCP> <37820@cup.portal.com>
Sender: news@sdd.hp.com (Usenet News)
Reply-To: tony@sdd.hp.com (Tony Parkhurst)
Organization: Hewlett-Packard, San Diego Division
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|> koz@frog.UUCP (Koz Egersheim) in <22504@frog.UUCP> writes:
|> 
|> I have recently come up on an HP ThinkJet Printer. The d____ thing
|> has the HP-IB (surpossedly = GP-IB IEEEE-488) interface.  This means
|> that it has a 24 (twenty-four, no mis-print) pin Centronics style
|> connector that needs to connect to my Amiga 1000 (I hope). 
|> 
|> Has anyone done this?  What is the pin-tp-pin scheme?
|> Will it work?  What printer driver did you use?


I had this EXACT same situation a few years ago.  What I ended up doing was
designing an interface converter that required some TTL inverter chips and
some resistors.  It took me about an hour to design, build and test, and it
worked the first time.  The basic idea was that in order to avoid the 
protocal and addressing stuff for HP-IB, put the printer in the "Listen-Only"
or "Listen-Always" mode, then the logic needs inversion, and the HP-IB
is open-collector, so you need resistors.  Since the A-1000 has +5 volts
on the centronics connector, no need for another power supply.  If you like,
I can mail you a schematic, or, I may be able to dig up the one I used.
(I even had one evaluated by Black-Box, but they apparently weren't
interested (perhaps it was too low cost:-)).

I didn't do much with graphics on the ThinkJet, so I used the generic driver


-- Tony