The good news is the workaround works :)
The bad news is I don't get too far into the kernel initialising, with
the following repeating:
(apologies for the .jpg, I have no other way to capture the messages).
Those errors appear immediately after the SCSI controller is found,
then keep repeating through the very slowed down boot process, until
just after an attempt to mount the root FS. Then it seems to freeze)
The machine is a Quadra 605 - from a previous boot with a 2.2.19 kernel
the scsi info comes up as:
mac_esp: io base at 0x50f10000
esp: using quick version
esp: addr at 0x50f10000
SCSI ID 7 Clk 16MHz CCF=4 TOut 138 NCR53C9x(esp236)
mac_esp: 1 esp controllers found
scsi0 : ESP236 (NCR53C9x)
scsi : 1 host.
Vendor: IBM Model: DSAS-3720 Rev: S47T
Type: Direct-Access ANSI SCSI revision: 01 CCS
Detected scsi disk sda at scsi0, channel 0, id 0, lun 0
scsi : detected 1 SCSI disk total.
SCSI device sda: hdwr sector= 512 bytes. Sectors= 1427328 [696 MB] [0.7