conflict with internal HD and external US in Mega STe

[czietz]

As for your original question. Iirc, you only change the ACSI ID on the ACSI-SCSI host adapter board. The SCSI hard disk always needs to be set to SCSI ID 0. Another option would be to change the ACSI IDs of the Ultrasatan: http://joo.kie.sk/?page_id=255.

[rubber_jonnie]

You're right, it doesn't make sense. It's also not true, i.e., both Frank and rubber_jonnie remember it wrong. The original Atari MegaSTE ACSI/SCSI host adapter does pass the ACSI bus through. You can still use external ACSI devices with the host adapter card installed.

(Maybe they were confusing it with the internal Ultrasatan adapter for the MegaSTE. That one indeed disables the external ACSI port.

Yes, that is entirely possible.