A 1540 Disk Formatting Disaster

I apparently made a big mistake! I own a VIC-20 and a 1540 disk drive. I accidentally reformatted a disk that already had programs on it. I used the following syntax: OPEN 15, 8, 15, "N0:DISK1 SD1,1B". I noticed that I didn't hear the usual "rattling" sound. I want to know if there is any way of recovering the lost or erased files. I almost had that disk full.

Jeff Lovell

Unfortunately, your programs were erased.

A number of things happen when you format a disk. First, the entire disk is erased, then the directory and BAM (Block Availability Map) are created. Next, timing and block markers are created, and the two-character disk identification code is written on every block of the disk.

To format a disk, use the syntax:

OPEN 15, 8, 15 : PRINT#15, "N0 : DISK NAME, ID" :
 CLOSE 15

where DISK NAME is any name up to 16 characters long and ID is a two-character identification code. Because of the way the format command works, this should be done only when the disk is new, or when the files on the disk are no longer needed.

As you can see, when a disk is formatted, any programs that were on that disk are lost.