Long Commodore Tape Saves

With long programs it is often not possible to finish typing in a listing in one sitting. I have been saving part of the program on tape and when I continue the second part, I erase the first part on the tape and rerecord the whole thing.

I would like to just continue recording with the next line number of the program. Please advise if there is a way.

J. R. Blundin

When you SAVE to tape, the computer first writes a header which contains information such as program name and starting address. Then the program is saved twice, and an end-of-file marker is written when the tape file is closed. (Commodore computers save programs twice as a safety measure.)

These SAVE procedures make it impossible to position the tape and append the second half of the program onto the first. Attempting this would probably result in a DATA error, and both halves might be lost.

During long typing sessions, you should SAVE your incomplete program occasionally (every hour or so). This way, if some sort of catastrophe happens, you won't lose the entire program. You can load the last version you saved and continue typing.

Also, it's not a good idea to continually rewind the tape and keep saving programs over the same section of the tape. Saving programs consecutively will afford another safety measure—you'll always have backup versions. If, for example, a tape becomes crinkled in one spot, you can rewind to the previously saved version.

Finally, when you SAVE a program, the cassette will perform the save, then stop. The place where it stops is where you want to start the next SAVE. Knowing this, you can save the time and worry involved in positioning or rewinding the tape.