EP_Count ($27) - Return number of files in File Area slot C

Register Parameters

IN:
   A = EP_COUNT
   C = slot number containing File Eprom Area

OUT:
   Fc = 0, File Eprom available
        HL = total of active (visible) files
        DE = total of (marked as) deleted files
        (HL + DE are total files in the file area)

   Fc = 1, File Eprom was not found at slot C

Registers changed after return:
   ..BC..../IXIY same
   AF..DEHL/.... different

Notes

Count total of active and deleted files on File Eprom in slot C (excl. NULL file on Intel Flash card).

Due to a strange side effect with Intel Flash Chips, a special "NULL" file is saved as the first file to the Card. These bytes occupies the first bytes that otherwise could be interpreted as a random boot command for the Intel chip - the behaviour is an Intel chip suddenly gone into command mode for no particular reason. The NULL file prevents this behaviour by saving a file that avoids any kind of boot commands which sends the chip into command mode when the card has been inserted into a Z88 slot. The NULL file is not part of the total active count.