Thank you so much for your reply and for the tool. I’ll try that.
Eventually I want to try to replace the xtide rom with multy flippy bios extension, whicch is also 8k.

Thanks for this OP. Allowed me to easily boot a HDD on my 286 TA P35 (AKA Olivetti PCS 286), which has a proprietary Olivetti BIOS that limits HDDs to just 2 specific models.

Thank you BurnedPinguin for this,
I also have an old Olivetti like giantenemycat,and I tried several times to upgrade the preinstalled 40mb hd with a CF card or another hard drive to the max supported by bios (100mb) , no matter the combination the end result (I could use the pc for a while, and suddenly...) was some nasty "unrecoverable memory error" that the only way to fix it was to remove some memory sticks , reboot and put them again. Now a 256mb CF is set up as primary and no errors whatsoever.

Tested on OLIVETTI M250 , 256MB CF: OK.

Only just found about this project - what a great idea.

Haven't used it yet, but I can think of several past machines where it would have been useful...

Thanks

This is so useful that the thread should always on the first page.