Bugbiter 240i pic converter / viewer------------------------------------The Atari APAC mode (any point, anycolor) has been already around sincethe late eighties. It 'merges' alter-nating lines of Gr.9 and Gr.11 toproduce all 256 Atari Colors in an80x96 resolution. An improvement tothis was APAC2 which alternates theorder of Gr.9 and Gr.11 lines witheach frame (interlacing). It doublesthe vertical resolution to achieve192 lines. Another variant is CINmode with 64 colors.Until now there have been APAC paintprograms that let you draw pics in256 colors, however real color photoson the Atari were only rarely seen.But not any more. The Bugbiter 240iconverter takes a standard Windows-bitmap picture and turns it into anAPAC or CIN format with interlace forthe Atari.For instance, you can now take allyour latest holiday snaps, convertand view them on your Atari in aslideshow. It even takes advantage of the full GTIA screen resolutionwhich is 88x240 for APAC and176x240 for CIN.Floyd-Steinberg dithering is used toproduce in-between shades and lowsaturated colors. It is amazing howwell our Atari can reproduce the na-tural colors of photographs that way.The converter runs on any Atari withminimum 48K. You will need an SIO2PCconnection cable and APE or AspeQt toread the source BMP pictures from thePC. A real Atari takes about 5 minsfor converting one image (an emulatorat full speed is of course muchfaster :-)A bitmap picture must have a max sizeof 352x240 pixels to be fit forconversion. So you'll have to sizedown digital photos beforehand.It also allows batch conversion forresizing big quantities of files inone go which is quite handy.Besides the size limit of 352x240 itis important that the picture issaved as a BMP file with 24 bit colordepth, triplet order B,G,R anduncompressed (standard BMP type).---The converter (BGPMAKE1.XEX)When all the pictures have been setto the right size and saved as BMPthe conversion can begin. The newoutput 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 startingup the converter is choosing the in-put drive which holds the source-BMPfiles. For calling a drive, there arekeys D (disk drive), H (hard disk foremulator) and keys 1-9 for the drivenumber. Both input and output drivesare displayed at the top of theDirectory screen.If there are any BMP files found onthe drive, they will be displayed inthe Directory window. Up to 255 filescan be displayed in 4 pages of 64files each.Keys I and O toggle between Input andOutput drive selection. The activeoption is marked at the top ininverse letters.When you press O, the word 'Output'gets inverted and you can then choosethe drive where the finished Ataripictures will be saved to with keys D/ H and 1 - 9. Always remember to dothis before starting the conversionbecause the startup setting is D1.At the screen bottom there is a smallcommand overview. Each keystrokepossible is marked with an inverseletter.Move the cursor with the arrow keys(no Ctrl) and use Space to mark afile for conversion. If you want tomark all the files in the directoryuse B for batch and then M. To unmarkall use B and then U.The Return key gets you to the nextscreen. If no file was marked thenthe one where the cursor was posi-tioned on is chosen.Settings screen:Here you see the conversionparameters. You can once more changethe output drive (with D/H 1-9), witch dithering mode (M) on and offand choose the conversion type (T)APAC or CINAPAC border color:An APAC Picture can be given a bordercolor with the arrow keys. You cansee that color around the picture ifit is smaller than 88x240 pixelsand doesn't stretch over the fullscreen. Default is black $00CIN Lumset adjustment:There are four luminance steps in aCIN picture. The configuration of theluminance registers Lum0 to Lum3 iscalled lumset and it is displayed as4 hexadecimal digits. The standardlumset is at 28AF and fits apicture with an even brightnessdistribution. However, for an idealconversion, the lumset should beadjusted to the particular brightnessof 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 shadesthen 026D is more likely to be good.A bit of trial and error will leadyou there.Space key selects the Lum register,arrow up/down flips through theregisters or changes it when chosen.With Return you confirm your lumsetchanges, ESC discards the new settingand goes back to the previous screen.Long name and description:Each BGP picture file can hold a longfilename and an elaborate descriptiontext in its file header. Both arebeing displayed in the viewer duringpicture loading.The converter allows entry of a longfilename of max. 96 characters, thedescription can be up to 400 charslong. The TAB key toggles betweenlong name and description windows,ESC gets you back to the settings.START kicks off the conversionprocess. You can pause conversionwith any key, a following ESC key-press aborts the conversion, anyother key continues it.The colored edges show the Ataricolor found for the current pixel.A picture is finished when the whiteline reaches the right end.When you are converting severalpictures in a batch job you can seethe progress in a file list.Color palettes:The converter needs an .ACTfile for matching Atari colorsto the real image colors. Thisfile contains the RGB values of allAtari colors. The default file is LAOO.ACT. If the program won't findit on drive D1: a selection menu willpop up. You can call the menu with(P) during dir or settings screen.The resulting colors depend on thepalette file used. ALTIRRA.ACT, forexample gives realistic but not sosaturated colors. For NTSC hardwareOLIVIERN.ACT should be used.---The Viewer (BGPVIEW3.XEX)Handling the viewer is very similarto the converter. Drive selection isdone with keys D/H and 1-9. Unlikethe converter, the viewer supportsSpartaDos subfolders.A subfolder is shown in brackets.Return opens the folder. You can moveup one level with (U). The currentpath is displayed at the screen top.If the files have a .BGA or .BGCextender the APAC or CIN type willshow in the Dir list with a precedingsmall "AP" or "C" sign. Use thearrow keys to move the cursor and hitReturn to load the file.There are two slideshow modes: (S)is normal slideshow of all images inthe folder and (R) is random mode.The display duration in seconds forthe pics is set with the < > keys.Minutes can be set using shift.While the image is displayed, any keyreturns to directory. OPTION showsthe picture info. SELECT stopsinterlacing, holding SELECT andpressing START lets you toggle bothhalf frames manually, each being aregular APAC1 picture.It's amazing how more coarse andpixellated they seem and how bothimages working together give acompletely different impression.---Hints and pitfallsConvertion errors overwriting files:The converter creates a temp filewhich normally gets erased aftercompleting the BGP-file.Unfortunately this doesn't seem towork with APE and a PC. APE also actsstrangely when overwriting an exis-ting file. So always remove all .TMP and .BGPfiles in the destination folder firstto avoid overwrites.APAC and NTSC:NTSC monitors run higher frame ratethan PAL ones so the line jitter isless obvious. Sadly, an NTSC-onlymonitor cannot blend the hue andluminance lines together as this isa PAL specific feature. However, Ifyou own a multinorm monitor that candisplay both PAL and NTSC, it willlikely be able to create the blendingeffect also in NTSC mode. If itdoesn't maybe you can change thesetup to 'NTSC Comb' color mode.That should do the trick.Have Fun!The Bugbiter        07/28/2016