Color-Pad

Paints colour onto a screen picture with the joystick. Color-Pad sets INK, PAPER, BRIGHT and FLASH (each can also be left transparent) for the character squares you move over, with an undo command for mistakes. It is meant as the complement to Small Screen Painter (#63158): draw the picture in SSP, then colour it here. Pictures load and save as standard 6,912-byte screens, so any SCREEN$ can be coloured.

Color-Pad is by Kristian Boisvert and was published on the September 1986 tape of Byte Power (#63045). Like SSP it uses the joystick only.

Program Analysis

The tape file is one 2,708-byte BASIC program. After a title screen, line 10 enters the machine code in line 0 with GO TO USR 26945. The menu functions are BASIC:

• 100–160: Save the picture, held at 58623, as a 6,912-byte CODE file, with an optional VERIFY
• 200–240: Load a picture to 58623 and return to painting
• 300–350: Quit, with an “ARE YOU SURE?” prompt read by an INKEY$ loop; Y resets with PRINT USR 0

Notable Techniques

• The working copy of the screen sits at 58623, so that it ends exactly at 65535.
• The machine code is re-entered from BASIC with GO TO USR (26954), and RANDOMIZE USR 26715 and 26759 are called before it after a save or load.
• Line 1 checks PEEK 23681: Byte Power told readers to POKE 23681,0 before loading a program so that it stops after loading and can be saved with line 9999 as a personal backup; otherwise the program starts the code.

Appears On

Byte Power September 1986

Tape-based magazine. The September 1986 issue (Issue 2) of Byte Power, the monthly TS2068 tape magazine created by Eric and Kristian Boisvert of Pickering, Ontario, in May 1986.

Related Articles

Color-Pad

Color-Pad is somewhat the complement of SMALL SCREEN PAINTER. It will allow you to paint the screen.

Image Gallery

Note: Type-in program listings on this website use ZMAKEBAS notation for graphics characters.