Changes
=== Implementing a storage device driver ===
Using "drvtable" get gets the list of DPH addresses for each drive. This is actually fixed at FE2F and is referenced by the XBIOS.
Amstrad have extended the DPH.:
* +23,+24 - address of a DD WRITE SECTOR (XBIOS) compatible function
* +25,+26 - address of a DD READ SECTOR (XBIOS) compatible function
* +27,+28 - unknown function, but does call DD LOGIN (XBIOS) if successful
* +29,+31 - unknown function, calls RET
The XBIOS calls these and assumes bank 0 is active. If you write a driver in TPA space you will need to transition to and from bank 1 using selbnk etc.
=== Links ===
