<><><><><><>› This article taken from Z*MAG issue› 202. Tidied by Dean Garraghty, and› reprinted by THE OL' HACKERS ATARI› USERS GROUP, with thanks.› ================› *CAROLYN'S CORNER by Carolyn Hoglin›› This month's column is a departure› from my usual discussion about word› processing. But it does involve› printing - the printing of color› graphics.›› So far as I am aware, there are only› two programs for the 8-bit Atari that› will print screen graphics in full› color: YEMACYB/4, by Michael L.› Clayton; and PicPrint, by Kyle Dain.›› Each of these programs is designed› for Epson-compatible printers using› four-color ribbons. They employ a› clever combination of yellow, red,› blue, and black in dot patterns› created in a 4 x 4 matrix that result› in a hardcopy printout that may› include any or all of the 128 colors› available on the 8-bit Atari. Sample› picture files are included with each› program.›› Having only four colors in a color› ribbon would seem to allow only seven› hues plus the white of the paper,› since red and yellow make orange, red› and blue make purple, and blue and› yellow make green (didn't I learn› that in kindergarten?). However, the› program analyzes the color of each› pixel on the screen and mixes the› colors of the ribbon in varying› proportions in an attempt to achieve› a printout that matches the screen› display as closely as possible.›› A color's dot pattern may be made up› of only one dot for a very pastel› effect, or as many as 16 for the› brightest hue. For instance, a pale› pink might use only the red ribbon in› a pattern of widely separated dots,› allowing a lot of white to dilute the› red. Orange would be achieved by› printing yellow followed by red. › Yellow and red would each be printed› in the dot pattern required by the› shade of orange in the picture. Each› pass of the printhead prints first› yellow, then red, blue, and black as› required by the program's color› analysis.›› Paint programs usually employ› GRAPHICS 15 which allows your choice› of four colors per picture consisting› of 192 rows of 160 pixels each. To› increase the apparent number of› colors in a picture, a variety of› patterns composed of the four colors› are provided. YEMACYB/4 and PicPrint› faithfully reproduce these patterns› as well as the solid colors. With› the judicious use of DLI's (Display› List Interrupts - usually only› understood by advanced programmers),› a picture can even display all 128› colors at the same time.›› I have found that pictures loaded› into either of these fine programs› produce printouts virtually identical› to one another. However, the› programs themselves differ in many› ways.››› YEMACYB/4›› You may have guessed that the title› of this program (pronounced "YEM-a-› sibe") comes from the hues of a› standard color ribbon - yellow,› magenta, cyan, and black. (Magenta› and cyan look pretty much like red› and blue to most of us.)›› Incidentally, the original version of› this program ("YEMACYB" without the› "/4") is for non-color Epson-› compatible printers and involves› passing the same sheet of paper› through your printer four times using› individual yellow, red, blue, and› black ribbons. The program provides› a means of precisely aligning the› paper before each pass. While the› procedure is rather tedious and time-› consuming, the final result is the› same as if printed on an Epson JX-80› or a Star NX-1000 Rainbow.›› This program requires BASIC, but is› self booting. There are no DOS or› AUTORUN.SYS files on the program› disk, nor are they necessary. Only› Drive 1 is supported. The program› documentation states that your› graphic file must be in standard 62-› sector format (either GRAPHICS 7 or› GRAPHICS 7+ [GRAPHICS 15]), but I› found that it would load some, but› not all, compressed files as well.›› After the file is loaded, the picture› is displayed on the screen. Touching› a key brings you to the color change› menu. At this point, you may choose› to change your picture to monochrome. › Or, if you are printing in color,› here is where you have the› opportunity to change the colors in› each register (line by line, if you› wish). Unless you have a listing of› the pokes to memory locations 708,› 709, 710, and 712, and the colors› they produce, this is likely to be a› lengthy trial-and-error procedure. › You may also load DLI data that has› been saved on disk. When you have› finished your changes, the picture is› redisplayed for your approval. You› may go back to the color change menu› as many times as necessary. There is› no provision to restore the original› colors, or to go from monochrome back› to color without reloading the› picture.›› When you are satisfied with your› picture, you have the opportunity to› save the color changes you have made. › This color data is not saved in a DOS› format, but is unconditionally› written, for future use, on the last› six sectors of whatever single-› density disk is in the drive.›› My test picture took about 15 minutes› to print and was centered on the› paper both vertically and› horizontally. The number of the› column being printed is displayed on› the screen, beginning with 159 and› counting down to 0. While printing› is in progress, it can be either› paused temporarily or aborted.›› With the differences among monitors,› printers, ribbons, and paper, you may› find that the printout does not match› the screen display exactly. Included› with YEMACYB/4 is a separate utility› program to create your own modified› color pallette to use instead of the› default pallette provided.›› There are five more utility programs› provided, as well as a menu to select› them from. You must first load your› favorite DOS, then run MENU.BAS.›› The program YFLIPPER.BAS will mirror› flip a Micropainter picture file in› GRAPHICS 7 or GRAPHICS 15, and resave› it to disk.›› YSAVUSCR.BAS enables you to capture› to disk a GRAPHICS 7 or GRAPHICS 15› picture that is displayed in a BASIC› program.›› YDLISCON.BAS will convert that DLI› data from the last 6 sectors to a DOS› file and back again.›› YBAREBON.BAS is a few-frills GRAPHICS› 7 editor with text entry capability.›› YWINDOWS.BAS confused me. › Documentation needs to be provided› for this program.›› YEMACYB/4 is a powerful program that› does what it claims very well indeed. › A very nice feature is the file› COLCHART.PIC which creates a full-› screen 128-color display that also› functions as a reference color chart› when printed. The DLI data on the› program disk makes this possible. › This reference chart is a great help› when creating a custom pallette. The› documentation includes a chart of the› 45 dot patterns used to create› various hues which makes the concept› much more understandable.›› On the negative side, I found the› program somewhat awkward to use at› times, and wished it were possible to› redisplay my picture without going› round and round in the menu. If you› load the wrong picture by mistake,› you must proceed as if you intend to› print it through quite a few commands› before finally being offered the› option of starting over.›› Michael L. Clayton› Electronical Software› P.O. Box 8035› Rochester, MI 48063› (313) 942-9504››› PicPrint›› This program is extremely user› friendly and has the immediate› advantage of being able to load and› display graphic files from just about› any paint program written for the 8-› bit Atari. In many cases the program› automatically identifies the type of› graphic file and displays it› accordingly. A few files produced by› programs using GRAPHICS 7, GRAPHICS› 8, or mixed screens are loaded by› pressing console keys according to› instructions.›› Another advantage is that it supports› not only Epson-compatibles, but also› Atari XMM-801, and Canon thermal› printers, in color or black-and-› white. All drives are supported,› including ramdisks. After the picture› is loaded, it is displayed with an› overlaid menu window which provides a› great many useful options. Pressing› "V" allows viewing of the entire› picture until another key is pressed› to bring back the menu.›› If you have selected a non-color› printer, your picture is shown in› monochrome. If you have a color› printer, but want to make a› monochrome printout (using a black or› another single-color ribbon), you can› change the display to black and› white.›› In either case, you can change each› color register by choosing its number› (1 through 4) and then pressing + or› - keys. I especially like the way› you get instant feedback when making› these changes.›› Display List Interrupt data cannot be› originated from the program, but› pressing "D" will load the .P? files› from Philip Price's PD Painter› program files. These files provide› for displaying up to 128 colors in› one picture. The DLI's won't show on› your screen, but they will print on› paper. You may also flip your picture› - very useful for making T-shirt› iron-ons.›› Pictures may be changed to and from› GRAPHICS 8 monochrome mode. Whether› you actually see monochrome on your› screen depends upon what kind of› Atari and monitor you are using. If› you have an XE computer that outputs› separate chroma and luma and a› monitor and cord that supports this,› the picture appears in black and› white. If you are using an XL› computer, or your monitor or cord› only supports composite video, you› may see a lot of purple and green due› to artifacting. Since these colors› are not "real" colors, they will not› be printed as such, even on a color› printer.›› In this GRAPHICS 8 mode, you can also› switch to a negative image. This is› great for pics that normally display› white on a black background.›› Another plus is that you can restore› colors in GRAPHICS 15 pics if you› messed them up or have changed them› to black and white.›› You can save your picture in standard› 62-sector uncompressed format for use› with other programs.›› If you press "C", the values of the› color registers will be shown on the› screen (behind the menu window). › Unless you also want them on your› printed picture for some reason, I› don't advise using this option, as› there is no way to undo it short of› reloading your picture!›› When you are ready to print your› picture, you can use console keys to› enable double strike (great when your› ribbon is fading) and/or disable› ANTIC DMA to speed up the printing. › (For some reason, this last feature› didn't work for me.) The test picture› I printed took about 18 minutes to› finish. A nice touch is the moving› bar on screen indicating printing› progress. The printout will be› centered horizontally, but not› vertically, so you need to set your› paper so that printing begins about› one inch from the top.›› There are many factors that affect› matching the colors on screen to the› colors printed on paper. Try› displaying the same picture on two› different monitors, or on a monitor› and a TV set. They seldom are the› same. So which one is PicPrint to› match? If you can see that the› colors are not going to satisfy you,› you can abort the printing, reload› the pic and adjust the colors. There› is no programmed pause-and-resume-› printing feature, but I noted that› setting my printer off-line did not› cause an error for a good 30› seconds.›› Included on the program disk are two› valuable utility programs.› CONVERT.COM will convert pics to and› from GRAPHICS 8, ST PI3, and IBM› monochrome format. PAINTR.COM is› Philip Price's DLI program. A brief› explanation of PAINTR.COM is included› with PicPrint, but you should really› read the documentation in ANTIC› Magazine's September 1984 issue to› get the full benefit of this› sophisticated and powerful program.› Patrick Dell'era's enhancements to› this program are documented in› ANTIC's March 1985 issue.›› PicPrint is a compiled TurboBasic› program and must be run on an Atari› XL or XE computer. It will not run› correctly under the OmniView OS, and› you must be sure to disable BASIC› when booting. If I could change› anything, I would add the ability to› pause the printout, and possibly› disable BASIC automatically. But› this is nitpicking. If you have a› color printer (or even if you don't),› contact Kyle Dain to purchase› PicPrint!›› Kyle Dain› MKD Systems› 125 Goodview Drive› Apollo, PA 15613› (412) 727-7987› *+*+*+*+*›