Well, there were a lot more things which needed changing or fixing than I initially thought, but at last I'm close to releasing a firmware update which might warrant the adjective 'final'.
One thing which will hopefully be considered an improvement, at least in terms of flexibility, is the ability to use the ROM of the SIDE/SIDE2 cartridge alongside the U1MB PBI hard disk. This will be at the expense of the ATR swap button (which still works just the same when the external cartridge is turned off), but will allow the use of the previously redundant 256KB of banked cartridge ROM while the hard disk is in use. Not that there's much to put there yet, but hopefully some conversions will be forthcoming. We'll see.
Anyway: the only thing that worries me is that having the ATR Swap Button 'Enabled' is now ESSENTIAL to preventing the SIDE cartridge's loader from booting instead of U1MB's SDX ROM or a disk-based DOS on a partition. Leaving the swap button disabled has never previously served any practical purpose whatsoever, since the external cart ROM was always suppressed by the PBI HDD regardless. But now that disabling the button allows whatever is on the cart to boot while the HDD is active, I worry about people becoming hopelessly confused by the fact they must enable the ATR Swap Button in order to stop the loader on the SIDE cart from booting instead of SDX or an attached disk or HDD volume.
I was thinking of renaming the 'ATR Swap Button' setting to 'SIDE Cartridge ROM' and reversing the logic, but I don't know if that would be better or worse. To make the button work, one would then have to disable the cartridge ROM. As it stands, one must disable the cartridge ROM by enabling the button.
Really, I think things should have worked this way right from the beginning, but Candle was absolutely adamant that the SIDE cart's ROM should be totally redundant when the PBI HDD is enabled and I just went with the flow. The upshot is that until now, the SIDE loader on the cart would never boot if the PBI HDD was turned on, regardless of the button setting. Users are therefore conditioned to expected operation occurring regardless of the button setting.
Imagine running a build of Action!, etc, off the SIDE cart under SDX with your PBI HDD, though.
Any thoughts on the naming convention of the button option would be appreciated, anyway. As would any other thoughts on this change.
Edited by flashjazzcat, Sun Feb 3, 2019 3:20 PM.