I upgraded BOOTER to new version and I tested it again. I set internal or external ROM in VICE and at start in VIC screen was all working correctly. When I set 40/80 key and reboot VICE hangs - so I started monitor and saw same result which described Robert Willie (aka Hydrophilic) with MMU config problem. When I start computer at VIC screen all is ok and bank 15 is set. When I start at VDC screen in $FF00 is stored unusable value $16... really what there makes changes between 40 and 80 column screens?
Really see no difference if I start it on other screen, only 40/80 key status, address 215 value... if are there any differencies it cannot to be so important that it disables setting $FF00 to any value.
Thank you for explaining my problem, many thanks - I'll get new REU 1750 with free EPROM socket and want to burn it to EPROM - so it's for me important.
Commodore 64 was great, Commodore 128 is bigger, better, faster and more powerful... Commodore 65 was almost here, now is back in Mega 65 and is more than ever was...