Before we get too involved with making changes let’s provide a simple way to make backups of your master program (that is an empty basic program and machine code).
Break into the program (see instructions in the Pro/file manual-page 97) and then add these two lines:
9990 CLEAR: SAVE "PRO/FILE" LINE 9991: BEEP .5,30: SAVE "p/f" CODE 63488,2046: BEEP .5,30: VERIFY "": VERIFY ""CODE : BEEP .4,40: GOTO 9996
9991 BORDER 0: PAPER 0: INK 7: CLEAR 63487: LOAD ""CODE : CLS : POKE 23658,8WARNING: Later we will use many variables to save memory and you will change most lines to take advantage of them. However, do not use any variables in either of the above lines because the first thing that happens on execution is that all variables and data are erased!
Now, make sure you have a copy of your program and data before we use this to ever make a backup since all data will be erased. When that is done just type RUN 9990 or GO TO 9990 after you have started your tape. When you hear a beep, quickly press ENTER to save the machine code. When the next beep sounds you are done and the program will wait for you to rewind the tape and play it back for verification.
You can now create a new file or load in another or just break in again and repeat the process to make another master copy. Since these two lines remain you can make new master copies at any time.
When you load in one of these copies it will auto-run at 9991 which loads in the machine code and then it restarts as the original does.