››Bugbiter 240i pic converter / viewer›------------------------------------››The Atari APAC mode (any point, any›color) has been already around since›the late eighties. It 'merges' alter-›nating lines of Gr.9 and Gr.11 to›produce all 256 Atari Colors in an›80x96 resolution. An improvement to›this was APAC2 which alternates the›order of Gr.9 and Gr.11 lines with›each frame (interlacing). It doubles›the vertical resolution to achieve›192 lines. Another variant is CIN›mode with 64 colors.››Until now there have been APAC paint›programs that let you draw pics in›256 colors, however real color photos›on the Atari were only rarely seen.››But not any more. The Bugbiter 240i›converter takes a standard Windows-›bitmap picture and turns it into an›APAC or CIN format with interlace for›the Atari.››For instance, you can now take all›your latest holiday snaps, convert›and view them on your Atari in a›slideshow. It even takes advantage ›of the full GTIA screen resolution›which is 88x240 for APAC and›176x240 for CIN.››Floyd-Steinberg dithering is used to›produce in-between shades and low›saturated colors. It is amazing how›well our Atari can reproduce the na-›tural colors of photographs that way.››The converter runs on any Atari with›minimum 48K. You will need an SIO2PC›connection cable and APE or AspeQt to›read the source BMP pictures from the›PC. A real Atari takes about 5 mins›for converting one image (an emulator›at full speed is of course much›faster :-)››A bitmap picture must have a max size›of 352x240 pixels to be fit for›conversion. So you'll have to size›down digital photos beforehand.›It also allows batch conversion for›resizing big quantities of files in›one go which is quite handy.››Besides the size limit of 352x240 it›is important that the picture is›saved as a BMP file with 24 bit color›depth, triplet order B,G,R and›uncompressed (standard BMP type).››---››The converter (BGPMAKE1.XEX)›››When all the pictures have been set›to the right size and saved as BMP›the conversion can begin. The new›output file format has the extender›.BGP (Bugbiter picture) but for dis-›tinguishing APAC and CIN pictures›.BGA and .BGC are used.››Directory screen:››The first thing to do after starting›up the converter is choosing the in-›put drive which holds the source-BMP›files. For calling a drive, there are›keys D (disk drive), H (hard disk for›emulator) and keys 1-9 for the drive›number. Both input and output drives›are displayed at the top of the›Directory screen.›If there are any BMP files found on›the drive, they will be displayed in›the Directory window. Up to 255 files›can be displayed in 4 pages of 64›files each.›Keys I and O toggle between Input and›Output drive selection. The active›option is marked at the top in›inverse letters.›When you press O, the word 'Output'›gets inverted and you can then choose›the drive where the finished Atari›pictures will be saved to with keys D›/ H and 1 - 9. Always remember to do›this before starting the conversion›because the startup setting is D1.›At the screen bottom there is a small›command overview. Each keystroke›possible is marked with an inverse›letter.›Move the cursor with the arrow keys›(no Ctrl) and use Space to mark a›file for conversion. If you want to›mark all the files in the directory›use B for batch and then M. To unmark›all use B and then U.›The Return key gets you to the next›screen. If no file was marked then›the one where the cursor was posi-›tioned on is chosen.››Settings screen:››Here you see the conversion›parameters. You can once more change›the output drive (with D/H 1-9), ›witch dithering mode (M) on and off›and choose the conversion type (T)›APAC or CIN››APAC border color:››An APAC Picture can be given a border›color with the arrow keys. You can›see that color around the picture if›it is smaller than 88x240 pixels›and doesn't stretch over the full›screen. Default is black $00››CIN Lumset adjustment:››There are four luminance steps in a›CIN picture. The configuration of the›luminance registers Lum0 to Lum3 is›called lumset and it is displayed as›4 hexadecimal digits. The standard›lumset is at 28AF and fits a›picture with an even brightness›distribution. However, for an ideal›conversion, the lumset should be›adjusted to the particular brightness›of the picture (Key L). ›If bright colors are dominant a lum-›set of 2ADF could be more fitting.›But if the image has more dark shades›then 026D is more likely to be good.›A bit of trial and error will lead›you there.›Space key selects the Lum register,›arrow up/down flips through the›registers or changes it when chosen.›With Return you confirm your lumset›changes, ESC discards the new setting›and goes back to the previous screen.››Long name and description:››Each BGP picture file can hold a long›filename and an elaborate description›text in its file header. Both are›being displayed in the viewer during›picture loading.›The converter allows entry of a long›filename of max. 96 characters, the›description can be up to 400 chars›long. The TAB key toggles between›long name and description windows,›ESC gets you back to the settings.››START kicks off the conversion›process. You can pause conversion›with any key, a following ESC key-›press aborts the conversion, any›other key continues it.››The colored edges show the Atari›color found for the current pixel.›A picture is finished when the white›line reaches the right end.›When you are converting several›pictures in a batch job you can see›the progress in a file list.›››Color palettes:››The converter needs an .ACT›file for matching Atari colors›to the real image colors. This›file contains the RGB values of all›Atari colors. The default file is ›LAOO.ACT. If the program won't find›it on drive D1: a selection menu will›pop up. You can call the menu with›(P) during dir or settings screen.›The resulting colors depend on the›palette file used. ALTIRRA.ACT, for›example gives realistic but not so›saturated colors. For NTSC hardware›OLIVIERN.ACT should be used.››---››The Viewer (BGPVIEW3.XEX)›››Handling the viewer is very similar›to the converter. Drive selection is›done with keys D/H and 1-9. Unlike›the converter, the viewer supports›SpartaDos subfolders.›A subfolder is shown in brackets.›Return opens the folder. You can move›up one level with (U). The current›path is displayed at the screen top.››If the files have a .BGA or .BGC›extender the APAC or CIN type will›show in the Dir list with a preceding›small "AP" or "C" sign. Use the›arrow keys to move the cursor and hit›Return to load the file.››There are two slideshow modes: (S)›is normal slideshow of all images in›the folder and (R) is random mode.›The display duration in seconds for›the pics is set with the < > keys.›Minutes can be set using shift.››While the image is displayed, any key›returns to directory. OPTION shows›the picture info. SELECT stops›interlacing, holding SELECT and›pressing START lets you toggle both›half frames manually, each being a›regular APAC1 picture.››It's amazing how more coarse and›pixellated they seem and how both›images working together give a›completely different impression.››---››Hints and pitfalls››Convertion errors overwriting files:››The converter creates a temp file›which normally gets erased after›completing the BGP-file.›Unfortunately this doesn't seem to›work with APE and a PC. APE also acts›strangely when overwriting an exis-›ting file. ›So always remove all .TMP and .BGP›files in the destination folder first›to avoid overwrites.››APAC and NTSC:››NTSC monitors run higher frame rate›than PAL ones so the line jitter is›less obvious. Sadly, an NTSC-only›monitor cannot blend the hue and›luminance lines together as this is›a PAL specific feature. However, If›you own a multinorm monitor that can›display both PAL and NTSC, it will›likely be able to create the blending›effect also in NTSC mode. If it›doesn't maybe you can change the›setup to 'NTSC Comb' color mode.›That should do the trick.››Have Fun!›The Bugbiter        07/28/2016›››