***********************************************************************
This article is being presented through the *StarBoard* Journal of  the
FlagShip/StarShip  SIGs  (Special  Interest Groups) on Delphi and GEnie
telecommunication networks.  Permission is hereby granted to non-profit
organizations only to reprint this article or pass it along electronic-
ally as long as proper credit is given  to  both  the  author  and  the
*StarBoard* Journal.
***********************************************************************

     Printers & Interfaces...
     From: TROUBLESOME on DELPHI
 
I recently acquired a new Xetec SuperGraphix interface to go with my Star
SR-10 printer and noted that Xetec has been busy making subtle
improvements.

The most noticeable is the use of a *metal* 36 pin connector in place of
the plastic one that they usta use, a jacketed and shielded printer cable
(most likely to comply with the FCC Class B limits) and the termination of
printer pin 18 inside the interface itself.  For those that may not be
familiar with the Centronics interface, pin 18 on most printers is a 5 volt
DC supply.  It is possible to easily modify the latest version of the Xetec
to operate from the printer, thus eliminating the need to connect to the
cassette port (which doesn't exist on an SX-64, by the way).

All that you have to do is open up the interface and find the red lead
coming from the printer cable.  It is soldered to an unused eyelet on the
printed circuit board.  Desolder the lead from the board.  Next, locate the
red lead coming from the serial buss cable. It is soldered to the Vcc buss
on the interface PC board immediately adjacent to the point where the
serial buss cable is mechanically anchored.  Desolder this lead and cut it
off or tie it back.  Solder the red lead from the printer cable into the
hole that was vacated by the serial buss lead.  Your interface will now
operate from printer power.  You may wish to remove the red lead with the
cassette port connector from the serial buss DIN plug.
 
Aside from not having to connect to the cassette port, the modification
also makes the printer invisible to the computer if the printer is shut
off.  That means that the computer will react with the normal ?DEVICE NOT
PRESENT error if you attempt to print to a dead printer.  This will not be
the case if the interface is powered by the computer.
 
If you have a C-128 and you press the RESET button for any reason, you must
also press the reset button on your interface as well.  Otherwise, the
interface will not respond when attempting to print and you will get the
?DEVICE NOT PRESENT error.  Pressing the interface reset button also does a
cold reset of most printers, which will erase any downloaded character sets
or other user-defined functions.
 
For those in need of a better printer Computer Centers of America is having
a printer sale on Star Micronics and other quality printers.  For example,
the Star SR-10 typically sells for 470-500 dollars through mail order.  The
price that CCA is selling it for is about 370 dollars.  The Xetec
SuperGraphix is being sold for about 60 bucks.  Their phone number is
1-800-631-1003, except in New York state where it is 1-800-221-2760.
 
I've purchased items from CCA several times and I've been satisfied with
the manner in which they do business.  BTW, the Star SR-10 is a 200
characters per second printer with NLQ (at 50 CPS), all the usual Star
operating features, tank-like construction (real heavy duty) and a neat cut
sheet feeder.  I'm * very* pleased with mine.
 
P.S.  If you have an older SuperGraphix interface with a ribbon cable and
would like to modify it to get operating power from the printer, I will be
glad to supply printed instructions, complete with a parts list and
drawing.  Contact me via Delphi mail if you are interested.  Unfortunately,
it isn't practical to describe the changes to be made within the confines
of the Forum.

TROUBLESOME on DELPHI