dplatt@coherent.com (Dave Platt) (11/10/88)
In article <17269@vax5.CIT.CORNELL.EDU> pv9y@vax5.cit.cornell.edu (Adam) writes: > Has anyone done this kind of testing on the Grappler LS from Orange Micro? > It seems to be about the same price, but does everything in hardware so it > won't have problems when Apple upgrades to new drivers. I'm interested in > a DeskJet, but can't tell which interface is better. Any suggestions? I haven't tested the LS... last I heard (about a month ago) it didn't seem to be shipping yet. However, I've talked with people who have tested the Grappler LQ with the DeskJet, though... and I infer (from what I've heard) that the LS is an LQ-like device/package that's specific to the DeskJet. The reports I've heard re the LQ with the DeskJet were relatively disappointing; the print quality wasn't great, and the printer ran quite slowly. I gather that there are a few reasons for this: 1) The Grappler LQ works with Apple's ImageWriter LQ driver, and rescales the IW/LQ's 216 dot/inch output to the 300 dot/inch format expected by the DeskJet. The IW/LQ driver can use 3x-oversize fonts, but doesn't use 4x-oversize fonts such as can be used by the DataPak driver and by Apple's own LaserWriter IISC driver. For this reason, output created via the Grappler LQ can't really match the quality of the LaserWriter IISC, of the DataPak driver, or of the printer's own built-in and ROM-cartridge fonts. If the Grappler LS also uses the ImageWriter LQ driver, I expect it would have the same limitations in this respect. If, on the other hand, the Grappler LS uses the LaserWriter IISC driver, and connects via the SCSI port rather than over the Mac's serial printer port, then the LS might be able to produce true 300 DPI output. 2) The Grappler LQ has no way to make intelligent use of the printer's build-in and cartridge fonts (except, perhaps, for the built-in Courier 12-point font in draft mode). The Grappler LQ software and hardware never "see" the QuickDraw codes generated by the user's application, and thus cannot instruct the printer to activate its own fonts when appropriate; the Grappler LQ can only rescale the bitmaps generated by the ImageWriter LQ driver. 3) Shipping a page full of bitmapped data over the 19.2 kbit/second serial line to the DeskJet (via the Grappler LQ) takes quite a while... up to 6 minutes/page if data compression isn't/can't be used. If the Grappler LQ or LS can use the DeskJet's parallel ("Centronics") port rather than the serial port, it might be possible to cut the time significantly. I believe that the "Grappler LQ" technology has some inherent limits: it can't produce "true" 300 DPI output (only rescaled 216 DPI bitmaps), can't use the HP font cartridges, and is relatively slow. Any DeskJet driver that works by emulating an ImageWriter LQ would have these disadvantages. A higher-performance approach would be to emulate the LaserWriter IISC. Such an emulator might connect to the Mac's SCSI bus, and to the DeskJet's Centronics-compatible parallel port. It would not need to perform any rescaling at all, because Apple's driver for the IISC creates 300 DPI bitmaps using 4x-oversize fonts; it could transfer data to the printer much more quickly (at SCSI and Centronics-parallel speeds) after a simple SCSI-block-to-HP-PCL reformatting. It would be substantially immune to changes in the Mac's printer-driver interface, and would probably continue to work after Apple's proposed interface changes. It probably couldn't make intelligent use of the HP fonts, but this might be less of a disadvantage due to the emulator's higher potential throughput. Has anybody out there actually seen or played with a Grappler LS attached to a DeskJet? How does it work? How _well_ does it work? If anyone has regular access to this beast, please drop me a note... perhaps we can agree upon some test data (a few documents of mixed text and graphics?) and some testing procedures. A real apples-and-apples comparison between the Grappler LQ, Grappler LS, and the DataPak driver could be a _very_ useful bit of work!
dplatt@coherent.com (Dave Platt) (11/17/88)
I just spoke with someone in Orange Micro's tech-support department
concerning the Grappler LS printer-driver; I got enough information to
draw some meaningful contrasts between the Grappler LS and the DataPak
driver for the DeskJet.
BASIC METHOD OF OPERATION
- The Grappler LS isn't a complete, standalone driver. Instead, it
uses the Apple-supplied ImageWriter LQ driver, installs a bunch of
nonstandard hooks, and adds a proprietary printer-spooling
capability.
The LS software convinces the ImageWriter LQ driver that an LQ is
attached, and alters the IW/LQ driver's imaging parameters so that a
true 300 dot/inch image is created by QuickDraw (rather than the 216
dot/inch image normally created for the IW/LQ). 4x-oversize fonts
will be used, if available. The LS software then transmits the 300
dot/inch bitmap to the DeskJet at 19.2 kbits/sec; it does perform
DeskJet data compression.
- The DataPak driver is a stand-alone driver which does not require
the services of the ImageWriter LQ driver. It also creates a 300
DPI bitmap, and sends it at either 9600 or 19200 bits/sec, with data
compression as applicable. 4x-oversize fonts are used if
available.
HARDWARE INTERFACES
- Both the Grappler LS, and the DataPak drivers, are software-only
drivers that work via the printer's serial port. Neither includes a
serial-to-parallel converter, such as was included in the Grappler
LQ. [This probably accounts for the fact that the LS has a
street-price of somewhat less than the LQ.]
RESOLUTIONS
- The Grappler LS supports "faster" printing (75 dots/inch) and "best"
printing (300 dots/inch), as well as "draft" (text-only) mode.
- The DataPak driver supports "draft graphics" (75 DPI), "normal
graphics" (150 DPI) and "best graphics" (300 DPI), as well as a
"text only" draft mode.
PAGE TYPES
- The Grappler LS will (I infer) support all of the page-sizes and
orientations supported by the ImageWriter LQ driver.
- The DataPak driver supports several paper sizes, but only in
portrait mode; it doesn't currently support landscape mode.
Landscape support will be provided in the next version, I'm told.
USE OF PRINTER FONTS
- The Grappler LS can use the built-in Courier 12 font in "draft"
mode, as long as no fancy headers, footers, etc. are being used. It
cannot use the built-in font, or any HP font cartridges, in "faster"
or "best" modes; it's entirely dependent on the Mac-resident screen
fonts.
- The DataPak driver can use the built-in Courier 12 font in "text
only" mode. It can use the Courier 12 built-in font, as well as the
Times and Helvetica lookalikes in HP font cartridges, in all 3
graphics modes if the "Use HP fonts" option is selected. This can
greatly increase the speed with which a page can be printed,
although the HP fonts are not entirely identical to the Apple/Adobe
fonts and may produce subtly-different output. A "Precision
placement" option can be used to ensure that each HP-font character
is placed at exactly the correct location on the page; this
compensates for the slight differences between the spacings of the
HP and Apple/Adobe fonts, but slows down printing somewhat.
SPOOLING
- The Grappler LS comes with a proprietary print-spooling package,
which works with all applications that follow the rules-for-printing
in Inside Macintosh ("We haven't found any with which it didn't
work.")
- The DataPak driver does not include a print-spooler.
SPEED
- The Grappler LS can print the MS Word "Overview" sample document in
"best" mode at a rate of about 6 minutes/page on a floppy-based Mac
Plus. Faster machines, and those equipped with hard disks will
print somewhat faster; a figure of 4-5 minutes/page was quoted as
being typical. The best-possible printing time for documents of
this sort (in 300 DPI "best" mode) was stated to be in the
neighborhood of 3 minutes; the bottleneck is apparently the 19200
bits/sec serial connection to the printer. Printing in "faster" (75
dots/inch) and "draft" modes is of course a good deal faster.
- The DataPak driver prints pages in "best graphics" mode at roughly
the same speed (I don't have access to data using the same sample)
when Mac fonts are used. The DataPak's "draft graphics" (75 DPI)
mode appears roughly speed-equivalent to the Grappler LS's "faster"
mode. The DataPak driver can print an average page of 300 DPI text
_much_ faster (1-2 minutes) when the "Use HP fonts" option is
selected and a suitable font cartridge is installed.
SYSTEM COMPATIBILITY
- Both drivers are compatible with System 6.0[.2], and [I infer] with
System 4.2 as well. Both are dependent on the current Mac printing
architecture; the Grappler LS depends on the ImageWriter LQ driver's
internals to a significant extent, and the DataPak driver is
dependent on the existing (poorly-documented) printer-driver
interface.
- Both drivers will probably "break" when Apple changes the printing
architecture, as they've pretty much promised they'll be doing one
of these days.
APPLICATION COMPATIBILITY
- The Grappler LS will work, apparently, with any application that
works correctly with the ImageWriter LQ driver. It won't work with
PostScript-dependent applications such as Adobe Illustrator.
- The DataPak driver works with most applications. It's known to have
compatibility problems with MacWrite (cause uncertain, being
investigated) and with HyperCard and Microsoft Excel (both of which
break some of the rules). It won't work with PostScript applications.
COMPATIBILITY WITH OTHER PRINTERS
- The Grappler LS includes configuration files for the HP DeskJet, the
HP LaserJet, and other HP-compatible printers as well. If used with
a LaserJet, the printer must be equipped with 1 meg of memory, and
must be configured to use its serial port at 19200 bits/sec.
- The DataPak driver is designed for use with the DeskJet; it might
work with the LaserJet, but that's uncertain at this time. I
believe they're working on a version tailored to the LaserJet.
PRICES
- The Grappler LS lists for $125 (I believe) and seems to have a
street- price of under $100.
- The DataPak driver lists for $125; I haven't seen it discounted.
SUMMARY
The Grappler LS is somewhat less expensive, comes with a print spooler,
and appears to be compatible with more applications.
The DataPak driver is more flexible: it supports a compromise (150 DPI)
mode that's faster than 300 DPI and much more readable than 75 DPI. It
also can make intelligent use of the HP font cartridges; when a
printer is so equipped, the DataPak driver can print 300 DPI documents
2-3 times faster than the Grappler LS.
Both drivers are compatible with the current System software. Both
will probably break when Apple rearchitects the Print Manager and the
driver interface. Both vendors have told me that they'll update their
software when the new architecture is defined.
MY CONCLUSIONS
I'll probably buy the DataPak driver rather than the Grappler LS, due
primarily to its ability to use the HP font cartridges. The higher
price of the driver, plus the $125 or so for the Times ASCII cartridge,
will add about 20% to the total price of the DeskJet-plus-whatever
printing package, but will probably double the throughput in 300 DPI
text mode. For me, it's worth it.