Changes
/* Technical */
== Technical ==
Uses [[XD-DOS]] v2.10 (which supports the harddisc, and additionally supports external double sided 80track disc drives). The 20 MB harddisc is split into four partitions, with drive names D, E, F, and G (drive name C isn't used here, but may be used as RAM disc, in combination with Dobbertin RAM expansion). Under [[FutureOS]] the four partitions are named I, J, K and L. The hard disc is contolled controlled by this I/O Ports:
#FBE0 Dobbertin Harddisc Data Port
#FBE1 Dobbertin Harddisc Status, Reset
#FBE3 Dobbertin Harddisc DMA, Interrupt
#FBE4 Dobbertin Harddisc Reset
The hard drive interface is an PC-XT compatible hard disc interface. The CPC's port mappings are close to the PC-XT's port mappings.
The following information was obtained from Linux/drivers/block/xd.h and MESS pc_hdc.c.
Commands (incomplete list):
CMD_WRITE 0x0A write
CMD_SEEK 0x0B seek
Status (obtained when reading status register):
STAT_READY 0x01 controller is ready
STAT_INPUT 0x02 data flowing from controller to host
STAT_COMMAND 0x04 controller in command phase
STAT_SELECT 0x08 controller is selected
STAT_REQUEST 0x10 controller requesting data
STAT_INTERRUPT 0x20 controller requesting interrupt
== Other harddisc solutions for the CPC ==
