Unused ROM Anywhere?

[chysn]

I know all (or most) of the nooks and crannies in RAM where I can put little machine language routines.

Are there any such "empty" places in ROM? Something that is never used, where ROM hackers can put something short? I don't much care if it's KERNAL or BASIC. I haven't seen anything promising in the disassembly, but I figured I might not recognize such a thing.

[tlr]

Commonly enhanced kernals would strip out RS-232 routines and/or tape routines to allow space for added code.

[srowe]

There's some empty patch space in both BASIC and the KERNAL

• $DF52 - 40 bytes
• $E47C - 37 bytes
• $E4DA - 38 bytes
• $FF85 - 5 bytes
• $FFF6 - 4 bytes

[chysn]

Commonly enhanced kernals would strip out RS-232 routines and/or tape routines to allow space for added code.

Thanks! It crossed my mind that RS-232 might be a good candidate for general uselessness.

There's some empty patch space in both BASIC and the KERNAL

Thanks! It doesn't seem like much, but a few dozen bytes here and there might be useful.

[Mike]

There's some empty patch space in both BASIC and the KERNAL

• $DF52 - 40 bytes
• [...]

This space already contains my patch for the bugged multiplication routine in the BASIC interpreter.