@Tigger
1.3 supports Harddisks, thats the only major change between 1.2 and 1.3 on the prom.
Actually no, it's not.
The only difference between Kickstart 1.2 and 1.3 is a bugfix in expansion.library:
bug explainedThis bug resulted in AUTOCONFIG(TM) autoboot malfunctioning. Everything else worked, but you just couldn't boot from the HDD directly. AFAIK booting from floppy and then using the HDD worked. This is the reason why many older HDD controllers such as A590 have a jumper to disable the autoboot (to avoid crash with 1.2, but still allowing to use the HDD when booted off floppy).
What I meant with losing the HDD when you boot to KS 1.3 was with A600, A1200, A4000 built-in IDE. KS 1.x doesn't have the driver in the ROM.