Changes
/* Technical */
* If 'ROM read' is active then CPC will see 16 KB pages from the X-MEM flash at ROM slots 0-6 and 8-31. If boot from CPC, then ROM 0 will be from CPC.
* If 'free' is active, the CPC will also see 16 KB pages from the X-MEM flash at &40-&4f. All are visible regardless of booting from CPC or X-MEM. ROM select &47 contains the alternate lower ROM.
* When boot from CPC is active, OS and BASIC are from CPC and not from X-MEM but they can still be accessed at &40-&4f if free is set.
