Dij-It Video Digitizer Software The Programs and All Documentation Copyright ½1992 Paul Swanson and may be distributed freely provided they remain in original unmodified form. The programs included in this collection are for use with the Dij- It video digitizer. Whether you built the digitizer using instructions in the articles in Atari Explorer magazine or you purchased the digitizer kit, these programs will access the digitizer to produce pictures and sequences in various formats. In addition, PCONVERT.TTP is also included here to make it easier to convert picture formats. These are the latest versions of the programs, as of 1/23/92. They were compiled as .TOS applications instead of .PRG applications because a .TOS application automatically eliminates the mouse cursor, which is not required by any of these programs. The programs have been improved slightly and some bugs have been removed. The programs included are: DIJIT.TOS - Digitizes to a full-screen display using a pixel- doubling or a pixel-averaging method, or to a 2 x 2 display of 1/4-screen images. The full screen can be saved as a .PI1 file by pressing "S". DIJITI.TOS - Operates like DIJIT.TOS except it uses two frames for each picture, using the information on the interlaced frame to increase the horizontal resolution from the 160 pixels per line read to the 320 pixels needed for a full-screen display. This displays only in the full-screen format and saves the screen as a .PI1 file. DIJREC.TOS - Displays in a centered 1/4-screen format. Single pictures are saved, but the entire screen is saved, in a .PI1 file, including the text in the border areas around the picture. This program will also record 40-frame sequences, at 4 frames per second, for a 10-second recording by pressing "G". The recording is saved in a special format that can be read by DIJPLAY.TOS. DIJPLAY.TOS - Plays the 10-second sequence you indicate by entering a file specification. Hit any key during the display and, when the 10-second sequence completes, the program returns you to the desktop. This program reads the sequence files generated by DIJREC.TOS. DIJQPX.TOS - Operates like DIJREC.TOS except it converts each screen to a .QPX picture instead of a standard screen format. Single pictures are saved as .QPX picture files, which are 1/4- screen 2000-byte files. This program will also save sequences at 2 frames per second. The sequences take up the same 240,000 bytes that the sequences saved by DIJREC.TOS do, but QPX files are only 2000 bytes each, so the sequences store 120 frames, resulting in a sequence that is approximately a minute in length. DIJQPLAY.TOS - Operates like DIJPLAY.TOS except that it displays the sequences saved by DIJQPX.TOS. DIJTEST.PRG - This is the test program used for checking the wiring in your interface. QPXVIEW.TTP - View single QPX pictures by entering the file specification of one as the parameter. Press RETURN to exit back to the desktop. PCONVERT.TTP - Convert picture formats among .PI1, .NEO and .QPX. Note that the QPX files are 1/4-screen images with 8 grey shades, and QPX is a different method of representing the picture, so you will lose resolution converting from and to QPX. Enter HELP as the parameter to get a list of the commands. QPXTERM.TOS - A modem program that will receive pictures over the modem from any host that supports the QPX protocol. Separate documentation for this program is included in another text file. Contrast Control for your Dij-It Digitizer A contrast control can be added to your digitizer by moving one resistor and adding a jumper and one more 1K variable resistor. If you built your digitizer from the instructions in the Atari Explorer article series you can place your contrast control in zone 3 of the upper board in columns 4 through 10. If you built your digitizer from the kit you can place it in the area of zone 3 to the right of the chips, in columns 35 through 39. On the version built from the article, begin by removing the 470 ohm resistor connecting zone 3 column 13 on the lower board to zone 4. Connect by a jumper wire zone 3 column 13 of the lower board to zone 3 column 10 of the upper board. Connect zone 3 column 10 of the upper board to zone 3 column 8 of the same board. Place the 1K variable resistor so that its leads are in zone 3 columns 6 and 8 and in zone 4 column 7, all on the upper board. For the kit version, remove the 1K resistor connecting zone 3 column 26 to zone 4. Connect by a jumper wire zone 3 column 26 to zone 3 column 35. Use the 1K resistor you removed to connect between zone 3 column 35 and zone 3 column 37. Place the 1K variable resistor with its leads in zone 3 columns 37 and 39 and in zone 4 column 38. When you adjust the contrast you will notice that it varies the brightness of the picture. You must adjust the brightness when you adjust the contrast because the contrast control is actually only varying the part of the voltage divider that connects the ladder to ground. You have to compensate by varying the resistor that is connecting the ladder to +5 in order to keep the voltage at the inputs in the same general range. A little experimentation with this new control can greatly enhance the quality of the pictures you digitize. ÿ