Disabling The Atari Break Key
I want to inform your readers about a technique I discovered that disables the Atari's BREAK key, but does not need to be reexecuted after each GRAPHICS command. It is so simple that I wonder why no one has ever mentioned it, or if it conflicts with something that I have not yet found out:
POKE 566, 143 : POKE 567, 231 to disable and POKE 566, 84 : POKE 567, 231 to enable
The preceding statements change the BREAK key interrupt vector to point to address 59279 ($E73F) which contains a machine code PLA and RTI instruction used by the OS. This method will work only with the OS B ROMs, which contain the interrupt vector for the BREAK key.