24. I'm having trouble printing.

General comment on printing

It is important to note initially that HyperChem simply sends picture information to the printer drivers that you have installed in Windows (or Windows 95 or Windows NT). It determines basic device characteristics by requesting information from the driver -- for example, whether it is a PostScript driver, whether the printer is a raster device, etc. But all of the information that is sent to the printer is sent with standard Windows print operations: "Draw a circle of this colour at this location", "Draw a line of this colour from here to there." HyperChem and associated software have NO functions that are printer-specific. If you get unexpected results on printing, it is almost certainly due to a problem with the printer driver or how it is configured.

"Cannot print CPK images"

After we got hold of an HP DeskJet 660C and the newest drivers to play with, we found that though we got that "This plotter cannot print CPK images" error when HyperChem was running under Windows, everything was fine with Windows 95. A small utility that was supposed to request information about the current printing device gave correct results with the HP660 under Win'95, but crashed with the same driver under Windows.

We reported this stuff to HP. They eventually replied that the current series of colour drivers reports a value back to Windows which describes the available features; under some circumstances Windows is supposed to interpret this value and report a different value to the software that sent the query. Windows 3.1 and Windows for Workgroups 3.11 do NOT interpret the value; they simply send it straight back to the software, and this tells HyperChem that the printer is NOT a raster device.

Other software, such as CorelDraw, which can report on a printer's capabilities, shows the same information as HyperChem sees: these drivers appear not to have raster capabilities.

In other words, HP says that it is Microsoft's fault.

What to do about it? Well, switching to Win'95 will solve that problem. It is something that may be fixed in a future release of Windows. You can copy images from HyperChem to other software such as Write or Word for printing -- these programs do not bother to check whether the printing device can handle raster images or not; they just go ahead and try to print. HyperChem Lite uses a different set of tests to determine if raster pictures are printable, and we expect that future releases of HyperChem may also use different tests than the current set.

Weird rectangles in PostScript output from Molecule Presentations

We have been seeing a strange intermittent error with the current series of PostScript drivers in the 3.0.1 line, including both the ones from Adobe and the ones customized by Hewlett Packard. This includes both colour and black-and-white printers. The effect is noticeable when printing a balls-and-cylinders picture from the Molecule Presentations module of ChemPlus.

The effect is that sometimes between printing the last (central) part of a bond and the first part of an atom, the driver will add an instruction to print a filled rectangle between the closing point of the bond section and the starting point of the circle. This happens about once for every 30 or 40 bonds for large structures; we have not been able to see a pattern in the appearances.

The trivial work-around is to install the standard Windows driver for the HP LaserJet III printer, and use that driver to send your PostScript output to your printer. That driver handles full colour output, and it predates the errors in the drivers. Because the problem can be worked around in this way, we are pretty sure that the error lies in this series of new drivers. We have reported the problem to HP, but have not yet received a reply.

Unable to access hardware lock after installing HP LaserJet 5L

The installation package for the HP LaserJet 5L apparently reconfigures the parallel port such that HyperChem is unable to communicate with the hardware lock. According to one user who discovered the problem and a solution for it, a work-around is to install ONLY the PCL version of the printer driver, rather than the default printer driver. When the PCL printer driver is installed, it must be connected to LPT1.DOS (or whichever LPT you have the lock on); this can be set in the Windows Control Panel, Printers/Connect .

As of January 97, Rainbow Technologies has released new software for the dongle driver, version PD 5.3, that should overcome this problem. Please refer to the Hardware Lock Problems FAQ for more information on downloading the driver software for your particular system.

Unable to access hardware lock OR printer problems after installing printer with ECP hardware

Typically, this is a new printer whose driver software takes advantage of the high-speed ECP printer port to enhance the speed of print jobs.

Printer/Dongle problems under NT 4.0

If none of the above cases applies to you and you are running under NT 4, check out the NT 4 Problems FAQ.

General work-around for printer/dongle incompatibility

If you find that HyperChem and your printer will not peaceably co-exist although you can switch back and forth between the two (often by removing the dongle when you want to print) then the Support Desk suggests that you set up HyperChem so that it will put its images into a file. Under the Edit/Setup Image menu item (in HyperChem 5) you can specify that the image be saved as a bitmap or a metafile. Then, capture the image from HyperChem by choosing Edit/Copy Image. This will create a file with a default name. (If you are repeating this for several images in HyperChem, remember to rename the file each time.)

Then, you can leave HyperChem and use your favorite image viewer application in order to print the HyperChem files. The bitmap file can be opened in the desk accessory application, "Paint" and printed from it. The metafile can be opened and printed using a shareware application such as "PaintShop Pro" or "Media Blaze SE" or related. Shareware image viewers are available through sites such as Tucows or related.

[Products] [Sales] [Support] [Science] [News] [Corporate] [Search] [Home]