A BASIC program that was deleted with NEW or after a reset can be restored on Commodore computers as long as no new programs are entered or loaded (or the computer is powered off). For the C64, the following procedure has to be applied:
What are the respective commands for a C128 in C128 mode?
I know that the pointer to the BASIC text is at $2D/2E instead of $2C/2D and that BASIC start is at $1C00 if graphics are not used. But I think the Rechain Lines Routine (address $A533/42291 which is called by SYS) might be different.