MultiCD can be used to change to a 'new CD' without using CDDisk to write
a new partition offset onto the harddisk or having to reset the target.

The 'new CD' can be another partition on the current harddisk or on any
other harddisk on the SCSI bus that contains valid CD images. 


* For DEX boards use at least: CDBoot30.BIN or CDBoot60.BIN
  For Saturn use at least:     SatCD12.BIN or SatCD22.BIN
* Use at least: CDBIOS.COM v1.04
* For full feedback using CDBoot60.BIN, use CDMon v1.02
  (This will display the partition baseblock on an emulator reset.)




Usage: MultiCD [id [partition]]

 
- MultiCD id partition

This simulates an open door for 1 second, then changes to the new
CD at the specified SCSI ID and Partition.

NB. If an ID is selected with no HD then you will receive a
'Target did not respond' message, but as a side effect the emulator
will begin open door simulation. To close it, either reissue the
command with a valid ID and partition or close it via the MultiCD
main menu.



- MultiCD id

This displays a list of all valid partitions on the Harddisk with
SCSI ID id.




- MultiCD

This scans SCSI IDs 0..5 for any harddisks with valid partitions,
displays the results in a menu and lets you view the partitions on
each harddisk.

After scanning the 6 SCSI IDs, it requests the emulator to simulate an
open door. The target will now be able to detect the door as being open.



Pressing a highlighted digit [0..5] selects the corresponding SCSI drive's
partition list to be displayed. From here selecting a valid partition
causes this partition to become the new CD to be used for emulation and
closes the door.

'Escape' closes the door without changing to a new CD.
'R' rescans all the SCSI harddisks.
    (Use this if after an initial HD scan some are listed at 'busy'.)
'O' causes the emulator to simulate an open door.
'C' causes the emulator to close the door and restart emulation.
    (NB. Closing the door can take many seconds, so be patient.)




NB. The partition list indicates which partitions are active/inactive.
This is the partition that will be used on resetting the target.
It will not reflect accurately the current CD that is being used by
the emulator.




Error messages:
'Timed out on getting reply from emulator.'
- The CD emulator is not responding to the SCSI message being sent to it.
  This could be because the emulator hasn't been started.
  (For DEX, remember to do a RUN SelEmu.)

  Make sure the IRQ parameter for CDBIOS is correct.

  Possibly the emulator has locked-up (see below).


'SCSI Disk is still busy, and has timed out.'
'Target did not respond.'
- Try again, harddisk may be recalibrating, etc.

  NB. The emulator can lock-up if the harddisk is permanently busy, since
  its trying to communicate with the SCSI harddisk and always failing.
  So re-power up harddisk (disconnect HD or power down host machine.)


Finally, remember to have only the last SCSI harddisk in the chain
terminated.



The emulator will open the door when any of BuildCD, CDDisk and UpdateCD
are started. This is so that the SCSI bus isn't overloaded, which would
significantly reduce build time etc. This means that the emulator will
be left simulating an open door afterwards. To rectify this without
resetting the emulator and target use MultiCD and just 'Escape'
immediately to close the door and restart emulation.


TC.
Jan.96
