It was while byte-fighting BACKUP.BA for the TDD2 that I noticed the call: CALL 62297,X,Y (CALL 58980 for the 200.) Where X: X=1 Format Disk X=2 Write to disk X=3 Read from disk X=5 Seems to check status of disk? Where Y points to a four byte location: First two bytes: Location in memory to load or save from. Third byte: Sector Forth Byte: Unknown After the call is executed: First Byte: Error Codes > 1 Then Error = 3 Then Drive Not Ready = 5 Then I/O Error = 6 Then Write protected = 8 Then No Disk = 9 Then Hard trouble I used this call when I wrote SPELL2.CO and I'm sure there are other things I'm missing. FLOPY2 chould become 'THE' Dos for the TDD2