Pressing the turbo drive space button will show you how much space is occupied in the Fast Access drive.
The turbo drive can store up to 5 MB of space but will automatically Purge after 250 sales to increase the performance of the program. Those sales are then moved to the archive drive where they are hard storaged. Before performing a backup all sales in the turbo drive must be archived. See the section on performing a backup.
Press the archive storage space button to view how much space the program has left available to accumulate sales.
Up to 100 MB of storage can be used, however it is recommended that you create a backup on a weekly or bi-weekly basis. You can then move all of your sales to the archive and perform a backup and then a soft reset to clear everything out. This will keep it program functioning efficiently and give you multiple time periods you can look at. Those backups can be used with the secondary copy of the program to recreate any data set which you have created. You can import any backup the program has created, back into the program. Be sure and read the backup section thoroughly on how to use it properly.