
get rid of xxx(an,dn.b) things - clear dn first and use dn.w

*** CHANGE 521 IN h:srcc/HP_550C/transfer.asm TO 521 IN transfer.asm ***
<       moveq   #0,d7

---------------
>       moveq.l #0,d7

37.7  use black, new rle code


HP_550C and HP_Deskjet (supports HP_500C) printer drivers for Testing

version 37.4

(c) Copyright 1985-1993  Commodore-Amiga, Inc.  All Rights Reserved

This archive is provided by Commodore-Amiga, Inc.
For Developer Testing and Personal Use Only

-----------------------------------------------------------
Developers: If you have an HP Deskjet or HP_500C or HP_550C,
please test these drivers and mail any bug reports or comments to
carolyn@cbmvax.commodore.COM (preferred) or cscheppner on BIX
I am interested in both complaints AND good comments like
"this is fine" etc.

The following readme is outdated but provides useful information
related to settings.  There are no installation scripts in this archive.
The information regarding CYAN balancing in the following readme is old.
These new drivers use a modified version of Hewlett Packard's gray
balancing code rather than always using additional gamma correction
to correct cyan.

I like the settings of Threshold 8, Density 7, no R G B color correction,
Ordered dither (unless you are using ADPro or other self-dithering print
program, in which case you must set Threshold to 1 to disable all of the
in-driver corrections)

Changes to these drivers:

HP_Deskjet (/HP500C) Fixes:
- Stopped cyan correction when Threshold==1 (Threshold 1 is supposed
  to be NO correction, for use with ADPro and other self-ditherers)
- Set ped_PrintMode flag in dospecial.c ConvFunc whenever printable
  characters come by.  This will should allow final FF eject to occur
  if a FF and subsequent characters are sent in one CMD_WRITE.
- Corrected invalid escape sequence in aRIN which was not being
  executed because invalid.
- Added modified Hewlett Packard gray balancing code to transfer.asm
  to replace the kludge of always gamma-correcting cyan one extra step.

HP_550C:
- New driver (never on WB)
- Implemented color text capability
- Same fixes as above, which started here and migrated to HP_Deskjet


------------ outdated but useful readme -------------------------------
Installation
============
To install either printer driver on your system, just double-click
its Install icon (or from CLI, copy the files HP_550C and/or HP_500C to
your DEVS:printers directory).

Then bring up the Workbench Printer Preferences editor and select
the driver you want.

Read the rest of this README regarding proper PrinterGFX Preferences
Threshold and Density settings.

For those who don't wish to read this whole thing:

For HP_500C try Threshold 10, Density 7, Green and Blue color correction,
and ordered dither (unless you are using ADPro or another program with its
own dithering/printing, in which case you will probably need to set
Threshold to 1).

For HP_550C try Threshold 8, Densoty 7, and ordered dither (unless you are
using ADPro or another program with its own dithering/printing, in which
case you will probably need to set Threshold to 1).


About the Drivers - HP_500C and HP_550C
=======================================
HP_500C is a driver for the HP_500C.  This driver was also released as the
HP_Deskjet driver of Workbench 2.1/3.0.  The HP_500C uses black OR color
inks, but cannot use both at the same time.  The HP_500C printer does
not support color text in text printing.

The HP_550C supports color text, and can use both the black and color inks
when doing text.  When doing graphics in Color mode however, the HP_550C
driver will use only the color inks.

Both color and B&W graphics are supported. For compatibility the maximum
number of dots vertically is 3000 (at 300 DPI) when US Letter papersize
is specified. Select CUSTOM as papersize to get 3100 dots vertically.
For color graphics, 3065 dots (at 300 DPI) is used for both US Letter and
CUSTOM printer preferences. Other paper sizes are calculated as before.

Support for DINA4 and US Legal paper sizes tested and seems OK.


Threshold Settings for Adjusting Color Output
=============================================
Usually, the Preferences Threshold setting only affects B&W printouts.
This driver looks at your PrinterGFX Preferences Threshold setting
when doing a color graphic dump and applies a brightness correction
(lightening of the output) as listed below, based on your Preferences
threshold setting of 1 to 15.  In addition, a correction to make
CYAN one step lighter is applied.  On a greyscale graphic dump,
a fixed brightness correction is applied.  In either case (color or
greyscale), a threshold value of 1 will cause NO correction
to be applied.

Please test and see if any of these corrections are to your liking.
We suggest you select both Blue and Green color correction in Preferences.
We found Threshold setting 10 (correction enhanced -4) to be best on
the HP_500C and setting 8 best on the HP_550C.
(Art Department Pro users: use Threshold 1 - see the note later on).


-------------------------------------------------------------------------
Some additional tips from our previous (HP_500C) tester
=======================================================
1) For most color graphics, a setting of threshold = 10
   gives best results (or whatever that table is in the final
   version, currently thresh=10 is best) (NOTE - On HP_550C we
   found Threshold 8 was better)
2) For all color graphics using halftone dithering, with Red Color
   Correction OFF and Green and Blue Color Correction on,
     gives best results.
3) Color Graphics are not vibrant on normal or bond paper, use
   Paintjet paper (Clay Coated) for good color graphics.
4) Use Density = 7 for Color Graphics on Paintjet Paper,
   Density=6 for color graphics on normal paper.
5) For Grey Scale use Density = 7, halftone dithering for best results.

Basically, set threshold to 10, density to 7, dither to halftone,
Turn Red Color Correction OFF, Green and Blue Color Correction ON,
and forget about it.  Graphics will print out great all the time.

One caveat, when running low on Ink in a color cartridge, color balance
goes wacky, but not too wacky, so it makes it look like something
is wrong with the driver or program.  In fact replacing the ink cartridge
is in order, run a self test and you can see if the cartridge is going
south.
-------------------------------------------------------------------------

NOTE - These driver-applied corrections will have NO impact if
you have Floyd-Stienberg dithering selected.  In addition, if you
select Threshold value 1, there will be no corrections applied.


NOTE FOR ART DEPARTMENT PROFESSIONAL USERS
==========================================
If you are using a package with its own enhanced printing support
such as Art Department Professional by ASDG, you will probably want
to turn off all corrections and set the Threshold to 1 when you do
color or greyscale graphic dumps.  Otherwise, the driver corrections
will cause interference with the internal dithering and corrections
applied by ADPro.


Density Settings for Shingling and Depletion
============================================
The density settings over 4 control shingling and depletion:

/* Set Shingling and Depletion according to density:
 *
 * 1-3: No depeletion, no shingling (75, 100, 150 DPI)
 *   4: 25% depletion, no shingling (300 DPI)
 *   5: 25% depletion, 50% shingling
 *   6: 25% depletion, 25% shingling
 *   7: No depletion, 25% shingling
 *
 * Use density 7 for transparancies.
 *
 * Depletion is ignored in B&W mode on all models.
 */



For those who are interested in the technical details
=====================================================
These are the brightness corrections as controlled via Threshold:

* Lightening for grayscale printouts
* no correction if threshold = 1
	DC.B 	0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15	
* hard-coded correction otherwise
	DC.B    0,1,1,2,3,3,4,5,5,6,7,8,9,11,13,15

(note - there are two extra no-correction tables here in driver)

* Lightening for color printouts (CYAN correction uses threshold + 2)
* 1 = no correction (Threshold 1 means NO CORRECTION on any color)
	DC.B 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15
* 2 = no correction (but CYAN gets corrected with table 4)
	DC.B 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15
* 3 = no correction (but CYAN gets corrected with table 5)
	DC.B 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15

* 4 = enhanced linear -1 (CYAN uses table 5, etc.)
	DC.B 0,1,2,3,4,4,5,6,7,8,9,10,11,12,13,14
* 5 = linear -1
	DC.B 0,1,1,2,3,4,5,6,7,8,9,10,11,12,13,14

* 6 = enhanced linear -2
	DC.B 0,1,2,2,3,3,4,5,6,7,8,9,10,11,12,13
* 7 = linear -2
	DC.B 0,1,1,2,2,3,4,5,6,7,8,9,10,11,12,13

* 8 = enhanced linear -3
	DC.B 0,1,1,2,2,3,3,4,5,6,7,8,9,10,11,12
* 9 = linear -3
	DC.B 0,1,1,1,2,2,3,4,5,6,7,8,9,10,11,12

* 10= enhanced linear -4
	DC.B 0,1,1,2,2,3,4,5,5,6,6,7,8,9,10,11
* 11= linear -4
	DC.B 0,1,1,1,2,2,3,3,4,5,6,7,8,9,10,11

* 12= enhanced linear -5
	DC.B 0,1,1,2,2,3,3,4,5,5,5,6,7,8,9,10
* 13= linear -5
	DC.B 0,1,1,1,2,2,2,3,3,4,5,6,7,8,9,10

* 14= enhanced linear -6
	DC.B 0,1,1,1,2,2,3,3,3,4,4,5,6,7,8,9
* 15= linear -6
	DC.B 0,1,1,1,1,2,2,2,3,3,4,5,6,7,8,9

* 16= enhanced linear -7 (for CYAN when threshold is 14)
	DC.B 0,1,1,1,2,2,2,3,3,3,4,4,5,6,7,8
* 17= linear -7 (for CYAN when threshold is 15)
	DC.B 0,1,1,1,1,2,2,2,3,3,3,4,5,6,7,8

The enhanced corrections are hand adjusted correction tables
which are partway between linear and gamma correction.  These tables
were developed by Roger Uzun.

