[comp.os.vms] Parallel printers on a VAX

lhotka@incstar.uucp (Glamdring) (10/21/90)

We are about to acquire some parallel printers for our VAX.  Unfortunately our
VAX does not have any spare parallel ports :-(.  (We are getting the printers
through a corporate merger).

What is the best way to connect these printers to our 6410 running VMS?  Two
options come to mind right away - either get board(s) to provide the 6410 with
more parallel ports (3 of them) or get serial-to-parallel boxes to connect the
printers to DECservers.

Which approach is better?  What board would I need to provide parallel ports to
the 6410?  Is there a better solution that either of these?

Thanks for any and all help - please e-mail to me and I'll summarize if there
is interest in the results.
 ______________________________________________________________________
/ Rockford Lhotka				INCSTAR Corp	       \
| Systems Administrator				PO Box 285	       |
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jeh@dcs.simpact.com (10/22/90)

In article <680@incstar.uucp>, lhotka@incstar.uucp (Glamdring) writes:
> What is the best way to connect [parallel-interface] printers to our 6410 
> running VMS?  

Assuming your 6410 has a VAXBI bus (some 6400 configurations live quite happily
without one), you could get some DMB32's (three of them) to give you three
parallel ports along with 24 serial ports.  This would be hideously expensive 
($15K total) unless you need the 24 extra serial ports anyway. 

Although it would be possible to build a multiple parallel printer i/f for the 
VAXBI bus, no one has done so to my knowledge.  The minimum required complexity 
of a VAXBI option makes the price prohibitive.  

There are some general-purpose parallel I/O options for the VAXBI.  There is
DEC's DRB32, and ours (Simpact's) which is an exact emulation of two DR11W's.
However, no printer drivers that I know of will talk to these.  They're also
pretty expensive, as printer ports go.  

This leaves you with serial-to-parallel converters.  In my experience these
work well, and they're pretty inexpensive.  Black Box has several models in
their catalog.  Make sure you get one that matches your printer's electrical
interface (Centronics vs. Data Products) and physical connector, and make sure
it does xon/xoff flow control to the host.  Also, look out for printers that
have the Data Products "long lines" option.   

My personal advice is to get one withOUT a built-in buffer, or at least one
with a defeatable buffer, if at all possible.  The VAX print spooler system
does all the "buffering" necessary, and it is a minor annoyance to submit a
print job, look at the queue and find that the VAX thinks its done, only to go
to the printer perhaps half an hour later and find it out of paper.  You 
can't stop/abort a job that's in the buffer, either.  

Lantronix makes a LAT terminal server with a parallel printer port on it 
in addition to some number of serial ports.  This makes sense only if you need 
the extra serial ports anyway; otherwise, use existing serial ports with 
s-p converters.  

	--- Jamie Hanrahan, Simpact Associates, San Diego CA
Chair, VMSnet [DECUS uucp] and Internals Working Groups, DECUS VAX Systems SIG 
Internet:  jeh@dcs.simpact.com, or if that fails, jeh@crash.cts.com
Uucp:  ...{crash,scubed,decwrl}!simpact!jeh

grr@cbmvax.commodore.com (George Robbins) (10/22/90)

In article <680@incstar.uucp> lhotka@incstar.uucp (Glamdring) writes:
> We are about to acquire some parallel printers for our VAX.  Unfortunately our
> VAX does not have any spare parallel ports :-(.  (We are getting the printers
> through a corporate merger).
> 
> What is the best way to connect these printers to our 6410 running VMS?  Two
> options come to mind right away - either get board(s) to provide the 6410 with
> more parallel ports (3 of them) or get serial-to-parallel boxes to connect the
> printers to DECservers.

You might take a look at the DECserver 250 - It is set up to act as a server
for either parallel or serial printers.  Some of the third-party terminal
servers also provide printer ports.

-- 
George Robbins - now working for,     uucp:   {uunet|pyramid|rutgers}!cbmvax!grr
but no way officially representing:   domain: grr@cbmvax.commodore.com
Commodore, Engineering Department     phone:  215-431-9349 (only by moonlite)

mcc@WLV.IMSD.CONTEL.COM (Merton Campbell Crockett) (10/22/90)

In article <1753.2721c4a9@dcs.simpact.com> jeh@dcs.simpact.com writes:
>In article <680@incstar.uucp>, lhotka@incstar.uucp (Glamdring) writes:
>> What is the best way to connect [parallel-interface] printers to our 6410
>> running VMS?
>
>Assuming your 6410 has a VAXBI bus (some 6400 configurations live quite happily
>without one), you could get some DMB32's (three of them) to give you three
>parallel ports along with 24 serial ports.

Assuming your 6410 has a UNIBUS (it's supported but may be an option, I don't
have my manuals here at home), you could add three additional M7258 parallel
printer interfaces (LP11) which are supported by VMS.

As the LANtronics Ethernet Terminal/Printer Server was mentioned in the pre-
vious posting, you could also consider the Emulex Performance 4000 product.
It is a LAT TCP/IP server as is the LANtronics product.  Their one upsman-
ship in the LAT product race is a Centronics parallel printer port in add-
ition to the, more or less, standard 16 serial ports.

If your printers are Dataproduct printers, you can also buy a serial inter-
face for them.  It has a switch selectable Full Duplex ACK/NAK Protocol 
option which requires you to transmit the data framed by <STX> and <ETX>.
It returns an <ACK> when the data is correctly received without parity error
and a <NAK> otherwise.  It also uses <XON> and <XOF> and hardware signaling
for flow control.

Merton

Wright_RJ@cc.curtin.edu.au (Robert Wright) (11/22/90)

In article <1753.2721c4a9@dcs.simpact.com>, jeh@dcs.simpact.com writes:
> In article <680@incstar.uucp>, lhotka@incstar.uucp (Glamdring) writes:
>> What is the best way to connect [parallel-interface] printers to our 6410 
>> running VMS?  
> 
> Assuming your 6410 has a VAXBI bus (some 6400 configurations live quite happily
> without one), you could get some DMB32's (three of them) to give you three
> parallel ports along with 24 serial ports.  This would be hideously expensive 
> ($15K total) unless you need the 24 extra serial ports anyway. 
> [...]
> Lantronix makes a LAT terminal server with a parallel printer port on it 
> in addition to some number of serial ports.  This makes sense only if you need 
> the extra serial ports anyway; otherwise, use existing serial ports with 
> s-p converters.  
> 

Digital makes the DECserver 250, which, to quote the book, "is a high
performance full-function Ethernet-based server for both parallel and serial
printers".

We have one. It works well.

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