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X-DDOS

999 bytes added, 17:43, 2 December 2020
/* RSX commands */added content
* X-DDOS can be used as a rom 7 replacement.
* X-DDOS can autoboot CPM if it's drive ROM 0.
* X-DDOS has a checksum check
X-DDOS extras: |SYSCOPY, |TYPE, |GDUMP, |DIR128, |DIR64, |HELP, |XDRIVE
 
X-DDOS 2 extras: |COPY (great command to copy files from any drive/partition/user-number to any drive/partition/user-number. That can be users from 0 to 15 and A, B, C, D, E, F and G where C = RAMdisc and D, E, F, G = Harddisc)
|HELP,<number> - display list of RSX commands for the given rom <number>
|CPM or |CPM,<drive> - Boot CPM from drive A, or chosen drive. A=0,B=1,D=3,E=4,F=5,G=6. Can boot from D,E,F,G if HD is detected. Can't boot from drive C.
 
== Booting CPM ==
 
The process to boot cpm is the same on floppy discs and hard disk and uses a common read sector function that re-directs to low-level functions based on the chosen drive.
 
Using |CPM,<drive> you can define which drive to boot from.
 
When |CPM is executed:
* on 2.10 and later, the hard disc is detected and be4b is set to ff if detected, 00 if not detected.
* the bios jumpblock is copied to be80 from c07b.
* iobyte (0003) is set to 81
* the current drive is written to &0004. A = 0, B = 1, D=3 etc.
* 'enter firmware' (&ad33) jp is setup.
* the XDPB is queried to find the location of the boot sector
* the boot sector is loaded to &100.
* if the boot sector has code, then the boot sector is executed from &100.
== Floppy Discs ==
X-DDOS supports B drives on all CPCs with 80 tracks and 2 sides. It's compatible to the 704 KB Vortex format of the Vortex drives. Additionally it provides the Dobbertin Data- and System format (about 0.7 MB).
X-DDOS supports CP/M and CP/M Plus on 0.7 MB B-drivesand can boot from either disc drive.
== Hard Disc HD 20 ==
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