stephen_usher wrote:Derek_Stewart wrote:This driver is built into the TT, which is probably why the emulator recognises, the QWA file on the SCSI hard disk option.
That's actually not true.
The TT's ROM only has enough intelligence to scan the SCSI bus (as it does the ACSI bus, which is a simplified version of SCSI) and read the boot sector of disk ID 0. After this, as with ACSI, it relies upon the hard disk driver software, such as AHDI, ICD, HDDriver or PP's driver.
The MegaSTe only has ACSI but has an internal host adapter so that it connect to a SCSI drive. It's merely an STe in a TT case with a VME bus added plus a CPU booster (16MHz + cache).
As I mentioned, ACSI is actually a simplified SCSI bus and the host adapter acts as a translator. Early host adapters were simple and dumb.
Of course, once SMSQ/E boots it throws all of that away and relies upon its own drivers for the hardware.
Thank you for tge information, but why does the QLE.WIN file attached to SCSI 0 in the Hatari Disk setup only read and boot up when the System is set to TT, rather any other option on the system option.