Classic Computer Magazine Archive COMPUTE! ISSUE 86 / JULY 1987 / PAGE 100

Auto-Display Hi-Res Picture Maker

Jaideep Vijan

From a reader in Hong Kong, this utility turns any Apple II hi-res picture into a file that you can BRUN. Several display options are available. The program works under both DOS 3.3 and ProDOS.

"Auto-Display Hi-Res Picture Maker" is an Apple II program which will convert any normal hi-res picture file on disk into a file which can be BRUN. When you BRUN the converted file, the picture isn't instantly displayed on the screen; instead, it is drawn onto the screen. The picture can be drawn in a variety of ways.

To begin, boot up DOS 3.3 or ProDOS, enter the program, and save it to disk. It's important that you save the program with the filename AUTO.HIRES.PIC. When you run the program, it displays the main menu. Option 1 (instructions) outlines the steps needed to convert a file from an ordinary hi-res picture to one which can be BRUN and gives details of the memory locations used by the converted file.

Option 2 (load picture) loads a hi-res picture file from disk into the hi-res screen. When you choose this option, you are prompted for a filename. If you change your mind and decide not to load a file, press Ctrl-C and Return to display the main menu again. To view a catalog of the disk, press Return without typing anything. When you are ready to load a file, enter its filename and press Return. Filenames must start with a letter and be no longer than 15 characters for ProDOS or no longer than 30 characters for DOS 3.3. Once the picture has loaded, you return to the main menu.

Option 3 (try draw routines) lets you try out the various ways in which the picture can be drawn on the screen (there are five). When you select this option, you are given a choice of seeing one of the drawing routines or of returning to the main menu. To try out one of the drawing routines, type in its number and wait until it is POKEd into memory. After the drawing routine has finished, you return to the option 3 menu. Once you have decided which routine you like best, return to the main menu and go to option 4.

Option 4 (make auto-display hi-res picture) is the part of the program which converts the hi-res picture into a file which can be BRUN. When you choose this option, you are asked which drawing routine you want to use. Enter the number corresponding to the drawing routine that you liked best in the previous step. Then you are asked for the name of the file you wish to create (this will be the file that can be BRUN). Again, press Return by itself to view a disk catalog, or use Ctrl-C and Return to go back to the main menu. After you enter a filename, you are asked to confirm that this choice is correct. If you answer in the affirmative, the conversion takes place, and you return to the main menu.

Option 5 (see screen) lets you look at whatever is present on the hi-res screen. After you finish looking at the picture, press any key to return to the main menu.

Option 6 lets you change the disk drive or DOS prefix used by the rest of the program. The slot and drive apply if you are using DOS 3.3, while the DOS prefix is relevant only to ProDOS. If you are using DOS 3.3, enter the slot and drive numbers when prompted and you will return to the main menu. If you are using ProDOS, the program displays the current prefix near the top of the screen and invites you to enter a new prefix. If you enter an illegal prefix, or if ProDOS cannot find the directory you want, you are prompted to enter another prefix. (Note that you must enter a valid prefix in order to exit this option.)

Choose option 7 once you have finished and want to leave the program.

If a DOS error occurs, the program prints an error message and returns you to the main menu. If an Applesoft error occurs, the program stops after printing the error number and the line number in which it happened. Pressing Ctrl-C and Return while the program is running always returns you to the main menu, except when you are entering a prefix for ProDOS.