Saving Incomplete Programs

I recently purchased a Commodore 64 along with a 1541 disk drive. I know how to format a disk, SAVE a program, LOAD a program, and RUN it. However, I'm not sure how to SAVE a program that is not complete, then LOAD it back in to finish work on it. Also, if I LOAD a program and it has mistakes in it, I'm not clear on exactly how to correct these errors.

William H. Boothe

An incomplete program is SAVEd the same way a complete program is:

SAVE "filename",devno

(on Commodore computers, for example) where filename is a name you assign to the file (it can contain up to 16 characters), and devno is the device number (1 = tape, 8 = disk). The computer does not know (or care) if your program is complete or not.

To correct errors and make other changes to program lines, display the line you wish to change on the screen by typing LIST followed by the line number. When the line is displayed, move the flashing cursor to the desired place on the BASIC line using the cursor movement keys in the lower right of the keyboard.

To insert a character or characters into the line, move the cursor to the position where you want to insert, then hold down SHIFT and press INST/ DEL. This will insert a space each time you press the INST/DEL key. Now type your change, and press RETURN. To delete an unwanted character, move the cursor one character past the one to be removed, press DEL (without SHIFT), then press RETURN.

When you edit a program line and press RETURN, the corrected line is entered into the BASIC program in its proper place. Consult your user manual or Programmer's Reference Guide for further details.