When merging MS-BASIC programs with the MERGE command (see p. 119, MS-BASIC
manual), care must be taken with the program to be merged with the program in
memory: make sure that you have saved IN ASCII FORMAT the program to be merged.
Make sure also that the line numbers of both programs do not overlap or repeat,
because the MERGE function overwrites the lines in memory with lines from the
disk file that have matching line numbers. To avoid the problem, renumber the
program in memory with the RENUMB command described on p. 154 of the MS-BASIC
manual.