Fastload Cautions

(Originally from Syntax Error-Orange CA)
(Thanks to Commodore Club-South too)

If you use programs that utilize REL files, then this word of caution from Batteries Included is meant for you. Why Fastloads should not be used during execution of these files: The reasoning behind why these cartridges do not work is that the 1541 drive has five buffers. These buffers are used to transfer the information on a diskette to either the internals of the disk drive or to the computer. One buffer is for the disk drive to keep track of what is where on the diskette (Block Availability Map or BAM). The other four are used to transfer blocks of data to the computer (in most cases). A REL file requires three buffers which leaves only one buffer free. These cartridges will use these buffers without checking to see if they are in use. Normally the disk drive will see this and try to work around the cartridge. Now if the cartridge claims two buffers this would force the REL to use the BAM buffer. If this corrupted BAM is saved back to the diskette then it will scramble the disk the next time you try to write to it. This scrambling is often slow and not noticed until it is too late, so it is recommended you not use FASTLOAD type cartridges (with REL files). If you have a diskette which has been corrupted by FASTLOAD, or any other reason, the data can be saved by following these steps: 

(1) Make a backup copy of the disk, if possible. 
(2) Scratch all files off the data disk except those ending in REL and HDR. 
(3) Validate the diskette according to instructions in the disk drive manual. 
(4) Follow the instructions in the manual on creating a sequential file. 
(5) Get a printout of the old record format. 
(6) Get a printout of the field list, so you know the field length. 
(7) With the information from 5 & 6 re-create the record format on the diskette which now contains the sequential file. 
(8) Read the sequential file into the new record format, then delete the sequential file.