At 10:44 AM 2/20/98 -0500, you wrote:
>of my programmers says I can get a Twinax to RJ45 connection device that
>will allow me to send the data through the network in this manner and
>that will make the printer act like a direct device.  I think the whole
>reason for management wanting the printer hooked up directly is because
>it is taking too long for a large (500+ page) print job to do its Host
>Print Transform before it actually gets sent to the printer.  Finally,
>what functionality will I gain by hooking up directly?  

SCS (SNA Character String) is an IBM slang term that essentially means
native pre-formatted AS400 text oriented printer strings.  These are
typically sent to a specific AS400 printer model (ie:  3812, 5224, 5219,
etc) with formatting information related to the printer device type as
defined in the related writer on the AS400.  The information is formatted
by the AS400 writer as it is sent to the printer.  

Host print transform is used on the AS400 to pre-format AS400 SCS printer
strings into ASCII strings that are pre-formatted for a specific PC type of
printer like an HP LaserJet.  This is a cycle intensive job on the AS400
that I believe is more suited to be offloaded to the Printer or the
PC/Printer combo.  Why waste AS400 cycles on this job?  The number of ASCII
printer types available on the AS/400 are limited.

There are black boxes that allow you to connect the laserjet to the AS400
via twinax and that is not a JetDirect card.  One version of this "protocol
converter" fits into the MIO slot of a LaserJet.  When connected via twinax
(or via a UTP balun/twinax system) you will appear as one of the 7 twinax
devices on that twinax port (addr 0-6).  This is a "real" physical device
like a 3812 emulated printer.  It is no more direct connected than a LPD
TCP/IP ethernet connected printer except that the black box is doing the
"host print transform" on the fly instead of the AS400 (an a relatively
efficient place to put it).  Furthermore, a twinax attached printer like
this has all of the traditional start, restart, select, etc options
available that are not generally available with LPD.  AS400's poll these
devices and know their status at all times (hopefully).

To my knowledge, aside from the impending TCP/IP LPD client from Synapse
(, there are no Windows based LPD clients that can read and
print native AS/400 SCS printer strings.  Their LPD client will print
native SCS strings and allow spooling, restart, recovery, etc.



Jerry Draper, Trilobyte Software Systems, since 1976
Specializing in connecting PC's, Windows, MAC's, and LAN's to the AS/400
Representing Synapse, Apple, IBM, UDS, MI, DCI, Netsoft, etc.
(415) 457-3431; (415) 258-1658fax;

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