From: sje@xylos.ma30.bull.com (Steven J. Edwards)
Subject: HP LaserJet 4 expansion answers
Reply-To: sje@xylos.ma30.bull.com
Organization: Bull HN, Worldwide Information Systems, Billerica, Mass., USA
Distribution: comp
Date: 5 Jan 93 17:35:55

Here are some hopefully accurate answers to a few questions I posted
earlier about expansion options for the HP LaserJet 4 printer.

1) Postscript

There are two approaches to generate PostScript output on the LJ4.
The first is to have a rasterizer program like GNU's ghostscript
running on some machine that later transmits the bitmap to the printer
using PCL5 commands.  The second and more standard method is to
purchase the LJ4 PostScript SIMM upgrade and install it in one of the
four SIMM slots on the starboard side of the printer.

The PostScript upgrade SIMM uses up half (16 Mbyte) of the full (32
Mbyte) expansion memory space of the LJ4.  It does not include any
RAM.  It may be possible to produce very simple PostScript pages with
only the 2 Mbyte base RAM on the LJ4, but this is not the recommended
operation.  At least an extra 4 Mbytes SIMM memory is suggested.  It
should be noted the the Postscript SIMM upgrade includes not only
the Adobe based interpreter but also the "standard" 35 fonts.

One vendor offers the PostScript upgrade for about US$350.

2) Memory

With PostScript installed, at least 4 Mbyte and up to 16 Mbyte of
extra SIMM memory can be installed using one or more of the three
remaining SIMM expansion sockets.  HP LJ4 SIMMs are offered in 1, 2,
4, and 8 Mbyte sizes.  If the SIMM sockets are standard, then third
party SIMMs may (apparently) be substituted.  This area needs some
exploration.

From the rather flexible organization of SIMM options, I assume that
all SIMM expansion memory space has an eight bit access data path.

One vendor offers an HP LJ4 4 Mbyte SIMM for about US$230.

3) LocalTalk Multi-I/O

The LocalTalk Multi-I/O option fits into the single I/O expansion
slot.  It is the least expensive of all the available I/O expansion
options and it provides a standard DIN mini-8 LocalTalk 230,400 bps
connection.  I assume that the appropriate Macintosh printer driver
software is included.

One vendor offers the LocalTalk option for about US$180.

In summary, one can do a field upgrade of a LJ4 into an LJ4M by
thinning one's wallet by about US$760 and a few minutes with a
screwdriver.

However, it appears that some clever value adder could provide a
Mac/LJ4 printing solution analogous to the techniques used to drive an
HP DeskJet (serial/parallel PC hookup) from a Mac.  The idea is to
come up with a software solution, at least for QuickDraw bitmaps, that
would permit a simple RS-422 non-network connection from a Mac to an
LJ4.  For Mac users that don't need networking and don't need
PostScript (or have their own rasterizer), this may be preferable to
the three part expansion listed above.  On the other hand, those with
speed, expansion, and network interests (like myself) will be better
off by going the HP expansion route.

 [The above opinions expressed are my own; not necessarily held by others.]
      == Steven J. Edwards           Bull HN Information Systems Inc. ==
      == (508) 294-3484              300 Concord Road         MS 820A ==
      == sje@xylos.ma30.bull.com     Billerica, MA 01821          USA ==
"That Government which Governs the Least, Governs Best." -- Thomas Jefferson
Newsgroups: comp.periphs.printers