This program was published in Electron User in November 1987 but would only display a single side of a disk. As I have a double-sided drive, I decided to modify it show both sides. With the original program, you also needed to break out of it by pressing ESCAPE to re-run for a change of disk. I have added lines to prompt you to insert a disk and press RETURN before the display is shown, so that it is easier to change disks.

A single-sided disk is shown, as before, but for a double-sided disk, the display of the tracks is narrower and the numbers above are doubled. Also, the data below is amended.

When the display is completed, a message is printed to ask you to press R to re-run the program or SPACE to exit.

If you display a DS disk with a large amount of free space, the display can take some time to complete. I have managed to convert the program to a m/code file which speeds this up quite noticeably. It was made up after some experiementing and by doing it in several stages, the assembler listing has become rather untidy. If I can rearrange this, I will send it in later - it will illustrate some other points in converting BASIC to M/code.

Richard Dimond, EUG #25

Richard Dimond